Tag: Magnolias

Need a focal point in the garden but lack space? Want something that will produce a brilliant show without much work on your part? Looking for a tree that isn’t going to need constant pampering?

The answer to all three of those questions is a saucer magnolia.

In our guide to growing magnolias, we discuss how to cultivate these trees in your landscape. In this guide, we’ll zero-in on the saucer magnolia, and how to make this tree thrive.

Here’s what I’ll cover:

It always helps to understand a bit about a tree’s history before you jump into growing it. That way, you can have a good idea of what the plant needs. Let’s go over that first.

Cultivation and History

Saucer magnolias (Magnolia x soulangeana) don’t appear naturally in the wild.

They’re cultivated hybrid crosses of two magnolia species: lilytree (M. denudata) and tulip magnolia (M. liliiflora).

The Yulan, Chinese, or lilytree (M. denudata syn. M. heptapeta) magnolia is native to central and eastern China and has been cultivated for hundreds of years, with records of specimens planted in Buddhist temples dating back to 600 AD. It arrived in England in 1780.

M. denudata trees grow up to 30 feet tall and produce lots of citrus-scented, thick-petaled white flowers.

The Mulan, purple, red, lily, or tulip magnolia (M. liliiflora) hails from southwest China and has been popular in Japan for centuries, though it’s not native there. It was introduced to Britain in 1861 from Japan.

It’s smaller than many other species, at just 12 feet tall or so. The flowers are pinkish-purple.

Saucer magnolias combine the best features of both species.

They are small in stature at about 20 feet tall and 15 feet wide at maturity. In the early spring in Zones 5 to 9, large white, pink, and maroon flowers bud out on the stems and open up with a cupped or globular shape, measuring up to 14 inches in diameter.

The flower color, size, and shape varies depending on the cultivar. The one feature they all have in common is that the trees are extremely floriferous. When they’re in bloom, you can hardly even see the branches underneath.

After the flowers fade, they are followed by alternate, elongated leaves. Underneath all that is smooth, gray bark.

When they’re young, the trees tend to grow in quite an upright habit, but they take on a rounded or oval shape as they age.

We have French botanist and biologist Etienne Soulange-Bodin to thank for this flowering wonder. He tinkered around with the parent species and eventually bred and named the saucer magnolia in 1826.

He was impressed with its prolific flowering, and it quickly became popular in France, England, and North America. Now, there are dozens of cultivars available and you can find this tree growing in landscapes and parks practically everywhere that has the right climate.

Saucer Magnolia Propagation

As a hybrid, it’s best not to try to propagate saucer magnolia from seed as it won’t grow true and your patience is unlikely to be rewarded.

Buying a plant from a nursery for transplanting or propagating via stem cuttings are both reliable ways to get started.

From Cuttings

Propagating stem cuttings creates an exact clone of the parent plant, so if you love a particular tree, you can take a few softwood cuttings and recreate it.

In the spring just after the leaves open, find a branch that is soft and pliable with new growth and healthy foliage. Cut about eight inches in length with the end at a 45-degree angle.

Remove all the leaves except the top two. If both leaves are relatively large when compared to other foliage on the tree, cut them in half vertically. Too much foliage will drain the limited resources in the cutting before it can develop the roots.

Fill a gallon-sized container with a seed-starting mixture. Dip the end of the cutting in rooting hormone and insert it into the center of the container about two inches deep.

Moisten the medium well and place the container in an area with bright, indirect light. If you live in a dry climate, it can help to tent some clear plastic over the cutting to retain humidity. Don’t let the plastic touch the stem cutting, though. Prop it up with a chopstick or other type of support if necessary.

Keep the soil moist and wait for the cutting to develop new growth. When new growth is apparent, you can transplant the rooted cutting into the garden in the spring or summer.

Transplanting

Purchasing a saucer magnolia from your local nursery or garden center isn’t as cheap as growing from cuttings, but you get a headstart, and it’s certainly much easier.

Plan to buy and transplant your young tree in the spring. Many trees do best when you plant them in the fall, but magnolias prefer to be transplanted in the spring.

When you bring home your potted tree, dig a hole that’s the same depth and twice as wide as the container the tree is currently growing in.

Remove the plant from the container and gently loosen up the roots. You want them to grow out and away from the center, not circle around, which might happen if the plant has been growing in the container for a while.

Spreading the roots helps prevent girdling the tree, which is when the roots grow in a circle at or below soil level, and can eventually strangle the tree.

Set the plant in the ground at the same height as it was in the container and fill in around the roots with soil. Water well and add more soil, if necessary.

The more compact saucer magnolia cultivars such as ‘Brozzoni,’ ‘Lilliputian,’ and ‘Verbanica’ can be grown in containers.

You want the tree to be sitting about the same height it was in the growing container or maybe an inch or two higher. Water well and add more soil if it settles.

How to Grow Saucer Magnolias

Saucer magnolias grow well in full sun to part shade locations in Zones 5 to 9, though shade will reduce flowering.

Saucer magnolias are pretty tolerant of conditions that trouble other magnolia species, like wind and alkaline soil.

The branches don’t break as easily as some species and though they prefer organically-rich, well-draining, slightly acidic to neutral soil with a pH between 6.0 and 7.5, they’ll tolerate a pH up to 8.0.

These trees do best in areas with consistently moist soil. Any extremes on either end of the spectrum, whether that’s too dry or soggy and waterlogged, will stress or kill the tree. 

That means you’ll need to irrigate if Mother Nature doesn’t provide the necessary moisture. Anytime the soil begins to dry out, add water until it feels like a well-wrung-out sponge.

It’s especially important to stay on top of watering for the first five years of the plant’s life. After that, it can tolerate a bit more variance.

Containers dry out faster than ground soil, so you’ll need to keep a close eye on the soil moisture, especially during dry spells.

Now, we have to talk about the heartbreaking part of growing this plant. After waiting patiently all winter long, in early spring the buds swell and the flowers open. Then along comes a late frost, and boom. The flowers are dead, and you have to miss out on this year’s display.

There isn’t much you can do to prevent this other than select one of the cultivars that bud out a bit later in the spring if your area is prone to late frosts. If you have enough frost cloth and you can reach the entire tree, you can cover it to protect the buds and blossoms.

Try to avoid planting next to a brick or cement wall that faces south. This area is usually warmer than the surrounding area and it might encourage the flowers to bud out earlier than normal, leaving them exposed to late frosts.

Pruning and Maintenance

Alright, strap in. We’re about to dive into the complex world of pruning magnolias. Wait, did I say complex? I meant to say incredibly simple.

You probably don’t ever need to prune your saucer magnolia, unless there’s a problem like a broken branch or signs of disease.

When the trees are young, you can prune them to encourage a more tree-like shape if that’s what you prefer, since they can sometimes take on a shrubby appearance.

Otherwise, prune off any diseased or damaged branches as you see them.

You don’t even need to prune to open up the canopy, as you do with some species, unless you want to. The best time to prune for shape is in the spring before the blossoms open.

If you are growing your specimen in a container, you shouldn’t need to repot, but if you start to see roots growing out of the drainage holes, remove the tree (enlist the help of a friend) and trim the roots and put the plant back in the pot.

Then, trim the canopy a bit to reduce the load on the roots.

Saucer Magnolia Cultivars to Select

Alba Superba

With large, heavily fragrant flowers that are mostly white with just a hint of purple blush at the base, this cultivar is dressed in a pale robe of flowers for weeks in the early spring.

It grows to about 20 feet tall, making it ideal for smaller spots.

Bred in The Netherlands at the Van Geert Nursery in 1866, This cultivar gained a steady following and nabbed the Royal Horticultural Society’s Award of Garden Merit in 1969.

Each blossom is deep purple and rose on the exterior and creamy white inside. So the tree looks vibrant pinky-purple as the flowers bud out and then takes on a bicolored appearance as they open.

The blossoms appear a little later than other saucer magnolias, and they might pop up again in the summer in smaller numbers.

Managing Pests and Disease

Saucer magnolias are relatively free from pests and diseases. I will, however, suggest that you set up camp in the spring as the buds are developing.

Arm yourself with an air horn and a good book, and blast the squirrels out of the area, because they will eat the flower buds.

Deer ignore them, though, so that’s a relief!

There really aren’t many diseases to worry about and the only insect pest to stress about is scale.

Scale

Magnolia scale (Neolecanium cornuparvum) is the largest scale insect in the US, coming in at nearly half an inch in diameter.

It’s a North American native and it doesn’t feed on anything but magnolias, with saucer being one of its favorites.

The pests are orange-pink and oval with a white waxy coating, and they use their sucking mouthparts to draw the sap out of the trees.

Light infestations may stress the tree, causing leaf drop or branch dieback, but in the case of a heavy infestation, a tree can die.

As they feed, the insects excrete a sticky substance known as honeydew. Not only does this drop onto the lawn, cars, walkways and anything else under the tree, but it also attracts unsightly sooty mold.

Learn more about how to deal with scale insects in our guide.

Tulip-Poplar Weevils

Tulip-poplar weevils (Odontopus calceatus) will chew holes in the leaves, but they aren’t anything to worry about.

Just know that if your tree has some holey leaves, that’s likely the cause. If it drives you nuts, treat them with insecticidal soap.

Verticillium Wilt

In terms of disease, verticillium wilt is evil. It can rapidly kill an otherwise healthy, mature tree and there is no cure.

Look for symptoms like leaf scorch, unusually heavy seeding, and branch death. Because the symptoms are somewhat vague, cut off a branch and strip the bark. If you see brown streaks or brown sapwood, you can confirm the problem.

If your tree is infected, you can’t save it. Remove it to prevent infecting other plants.

The fungus lives in the soil for years, so don’t plant anything there that’s susceptible to the disease for at least ten years. And many, many trees are susceptible.

The list of those that aren’t susceptible is pretty short. Try growing birch, ginkgo, juniper, spruce, pine, dogwood, hawthorn, fig, mulberry, oak, sequoia, and willow trees instead.

Best Uses for Saucer Magnolias

The saucer magnolia can be grown in a large container if you’re willing to prune consistently. Talk about a focal point on your patio!

You can also use the tree in espalier, but please, please don’t train it against a wall. The heat will reflect off the wall and onto the tree and cause it to flower a bit earlier, leaving it exposed to killing frosts.

Otherwise, the saucer magnolia makes a perfect specimen or background tree in the landscape. The more compact cultivars can make a major impact in a small space.

If you opt to allow the tree to take on a shrubby appearance, you can plant a few as a floriferous hedge for privacy or to create a natural boundary.

Magnolia flowers are also edible, and I find the blooms from saucer magnolias to be some of the tastiest.

The deeper the color, the more floral and citrus the flavor seems to be. Pickle them, use them in tea, or chop them up to add a bit of color to salads.

The southern magnolia is the state tree of Mississippi, sometimes called the bull-bay, big-laurel, large-flower, or evergreen magnolia, and can be cultivated in USDA Hardiness Zones 6 to 10.

As some of the common names indicate, the leaves look somewhat laurel-like, but they’re much, much larger and often have attractive bronze-colored undersides.

You’re probably already familiar with this North American native if you live in the South, but the trees can grow in a variety of climates outside of their native range.

They’re even popular in locations with completely different climates to the humid heat of the south, like England and the Pacific Northwest.

I have a tulip poplar that I’m itching to tear out, and when I do, a southern magnolia is going in its place.

I can’t wait to enjoy the year-round color and giant, waxy, fragrant flowers. Until then, I’ll continue to marvel at the many specimens growing in my neighborhood.

Do you fancy one of your own, too? We’re going to help make that happen by discussing the following:

Cultivation and History

The southern magnolia is classified in the Magnolia genus, which comprises about 240 species.

It’s native to North America, where it grows in the southeastern United States of Alabama, Florida, Georgia, Louisiana, Mississippi, North Carolina, and Texas.

It favors coastal plains, upland, and lowland areas, and doesn’t grow above 500 feet in elevation in the wild, but is seen in cultivation at higher altitudes.

It grows in areas that receive at least 40 to 80 inches of rain per year with temperatures between 15 and 90°F, in warm temperate or semi-tropical climates.

The species is the only evergreen in the Magnolia genus, and generally grows to about 80 feet tall, though some specimens have achieved much greater heights.

There are a few in Florida measuring over 125 feet tall. In cooler climates, they tend to stay much shorter.

Southern magnolias tend to be moderately fast growing, adding up to 18 inches of height each year, and require up to 50 years to reach their mature height.

They will start fruiting and flowering much sooner, producing flowers when they are just three years old and typically fruits appear when they are 10 years old. The trees can live up to 120 years.

Most have a pyramidal growth habit, but there are some cultivars with oval, round, or columnar shapes. The bark is smooth and gray, though older specimens take on a scaly texture.

The simple, alternate leaves are elliptic or oval shaped with solid (entire) margins.

The leaves are typically medium green and glossy on top, and brown or rust-colored and matte with a faint fuzz underneath. They can reach up to eight inches long. The foliage doesn’t change in the fall. Remember, this is an evergreen.

And then there are the flowers. The huge, showy, saucer-shaped blossoms can be up to 14 inches across and are creamy-white with a waxy coating and an intense lemon fragrance. When they’re blooming, the whole yard will be perfumed.

These blossoms appear in the spring and may sometimes reappear in the summer in smaller numbers.

After the flowers fade, small fuzzy brown fruit cones develop.

At maturity they are about five inches long and covered in bright red drupes, which the birds love. So do squirrels and other herbivores, especially when they fall to the ground.

Southern magnolias are cultivated around the globe and are popular in the UK, where they were introduced in the early 1730s.

It’s often confused with the sweetbay magnolia (M. virginiana), but sweetbays are smaller in every way, from the leaves and flowers to the height and trunk circumference.

Southern Magnolia Propagation

Southern magnolias are one of the easiest species in the genus to propagate.

These trees can be grown from seed. However, the resulting tree could be very different from the parent in terms of size, shape, growth rate, and flowering, unless you’ve managed to secure seeds from a species tree and not a cultivar.

If growing magnolia from seed is something you’re interested in, our guide has all the details. M. grandiflora is extremely easy to propagate by seed, so it’s an excellent option if you’re considering this method.

From Cuttings

Unlike starting from seed, propagation via cuttings will give you an exact clone of the parent plant.

Wait until the spring, when new growth has started developing at the end of the stems, and take an eight-inch cutting using clean, sharp trimmers. Make the cut at a 45-degree angle.

Remove all of the leaves except for the top two. Cut these in half vertically to reduce the amount of tissue the cutting has to support.

Fill a gallon-sized container with seed starting medium and poke a hole in the center.

Dip the end of the cutting in powdered rooting hormone and set the cutting into the hole you made. The cutting should be about two inches deep.

Soak the medium so it feels moist but not soaking wet, like a well-wrung-out sponge, and place the pot outdoors in an area with dappled or partial sunlight.

Keep the soil moist as the cutting develops roots, which can take a month or more. Eventually, you’ll start to see new foliar growth develop.

So long as the weather isn’t too hot and dry, when you see the new growth you can put the plant in the ground. However, I’d recommend keeping the plant in the container until the following spring or the following fall.

It’s best to transplant before the new specimen reaches four feet tall. A height between two and four feet is ideal.

Transplanting

It’s best to transplant southern magnolia saplings in the spring rather than the fall. Many trees do well when planted in the fall, but magnolias, in general, do better in the spring.

That said, if fall works better for you, they’ll probably be just fine. Southern magnolias are adaptable.

Young southern magnolias have long taproots, so be careful not to disturb or break the root. As the tree ages, the roots become more extensive with lots of lateral growth, rather than relying on the taproot.

These trees are prone to girdling, which is when the roots grow in a circle around the trunk, either at or below the soil line. This can act like a gradually tightening noose around the trunk, strangling the plant.

To help avoid this, be careful to spread out the roots when you transplant.

The roots grow extremely wide, so don’t place the magnolia too close to things like building foundations or a septic system.

Assume that the roots will grow four times as wide as the canopy width at maturity. Plants should be 40 feet apart, not just to accommodate the roots, but because the canopy can grow that wide.

Pick your location carefully because these wide roots make it difficult to transplant the tree if you need to move it later on.

Once you’ve chosen your location, dig a hole large enough to accommodate the root system of your sapling.

Place the plant only so deep that you can see the beginning of the root flare, which should put the bottom of the trunk about two inches above the surrounding soil line.

Then, backfill with soil. Heap three inches of bark or leaf mulch over the soil, but keep it away from the trunk.

If you place the plant too deep in the soil, the roots will want to grow upwards and outwards rather than down.

For the first four years after planting, the magnolia will be establishing its root system, so keep the soil moist but not wet.

The mulch will help retain moisture and reduce weed competition. If any weeds do manage to poke through, pull them up promptly.

How to Grow Southern Magnolias

Southern magnolias thrive in full sun to partial shade. When they’re young, they can tolerate nearly full shade, but as they mature, they need brighter sun.

Luckily, they tend to take care of that themselves by growing tall enough to escape the shade cast by shorter trees and shrubs. If young specimens are grown in shadier conditions, they might mature to have a shrubbier shape.

They prefer loamy, peaty soil, but a bit of clay or sand is fine, as well. The soil can be slightly alkaline, neutral, or acidic, but the ideal pH is slightly acidic, with a pH between 5.5 and 6.5.

The soil should be well-draining but able to retain moisture as southern magnolias need consistent moisture to grow best.

These trees can tolerate a bit of temporary drought, but if you live in a hot region with dry summers, it’s probably best to put your young magnolia in partial shade and heap lots of mulch on top of the roots to help the soil stay cool and retain moisture.

They will also tolerate temporary wet soil in the case of seasonal flooding, but don’t let it sit around too long, or it will cause root rot.

Once established, you won’t need to add any moisture unless you have an abnormally prolonged drought. The exception is if you live in a desert climate, the tree will require irrigation. The soil should be watered once it’s fully dry.

Pruning and Maintenance

The lower branches of southern magnolias tend to bend to the point where they can intrude on traffic or even touch the ground. Prune these off at the trunk.

You should also remove any branches that have a tight crotch, which means two branches are growing close together at their bases. These are weak and tend to break. Remove the smaller of the two.

Pruning is best done in late winter or very early spring before the buds start to swell. Make sure the air temperature has been above 35°F for the preceding days so avoid pruning frozen wood.

Otherwise, there isn’t any further work required. Southern magnolias are truly low-maintenance.

The biggest challenge will be leaf clean-up. Each leaf lives about two years and then it drops from the tree. Since each one can be eight inches long, it only takes a few to create a big mess.

And somehow, they can travel. My neighbor’s southern magnolia regularly sends leaves into my yard. That might not seem surprising, but this neighbor happens to be two houses away from me!

Insects

As mentioned, this tree is relatively resistant to pests and diseases. There are just a few insects that can be a problem.

Borers

Magnolia borers (Euzophera magnolialis), root collar borers (E. ostricolorella), and black twig borers (Xylosandrus compactus) all target magnolias, particularly trees that are stressed by drought or soggy soil.

Magnolia borers feed only on southern magnolias and are only found in the South.

The first two borers mentioned are brown moths and the black twig borer is a beetle, but it’s not the adults that you have to worry about. It’s the larvae that cause problems.

The larvae tunnel into the twigs and branches, producing cankers, frass, and round entrance or exit holes. As the tree suffers, it takes on a generally unwell appearance.

All three are opportunistic and typically attack trees that are already stressed or sick. If you cure the original problem, they will often head to greener (erm, browner?) pastures.

However, black twig borers can introduce Fusarium solani, a nasty infection which causes twig death and can even kill small trees.

Scale

Magnolia scale (Neolecanium cornuparvum) is a soft-scaled insect that doesn’t hang out in one spot like your typical scale species.

It’s highly mobile, crawling up and down the tree looking for the best spots to feed on the sap using their sucking mouthparts.

They’re also one of the largest types of scale insects in North America at half an inch in length. They have a protective waxy coating over their pinkish-brown bodies.

As you can imagine, given their size, a large infestation of these insects can cause serious damage. They can weaken a tree enough to kill it.

Plus the honeydew they secrete attracts sooty mold and makes an unholy mess under the tree. Woe be to anyone who parks their car under a magnolia infested with scale – I say this from experience.

The good news is that southern magnolias aren’t their preferred source. They’ll generally shoot for star (M. stellata) and cucumber magnolias (M. acuminata) first.

Natural predators should keep scale populations in check, but if you spray insecticides in your garden, it’s likely that populations of predators like lady beetles and lacewings have been reduced.

In that case, stop spraying, if you can, and introduce these beneficial insects into your garden.

Ladybugs are suffering due to their popularity for releasing into the garden and wild populations are under threat.

That’s why it’s vital that you try your best to make your garden a place where they can thrive.

This disease attacks many, many species and can kill a huge, mature tree or beloved shrub that has been around for decades in just one season. Plus, there is no cure. Sadly, southern magnolias are susceptible.

Leaf scorch, heavy seeding, and branch death are all common signs. If you cut off a branch and strip the bark, you can see brown streaks or brown sapwood.

If your tree is infected, there’s nothing you can do but remove it. And, because the pathogen lives in the soil for years, you can’t plant anything there that’s susceptible to the disease for at least ten years.

Ginkgo, juniper, spruce, pine, sequoia, birch, dogwood, hawthorn, fig, mulberry, oak, and willow trees are all resistant options.

Learn more about common diseases that affect magnolias in our guide.

Best Uses for Southern Magnolias

As a shade tree, there are few rivals. The southern magnolia works in home gardens, commercial areas, and parks.

Just keep in mind that nothing but complete shade lovers will grow underneath them. Don’t plan to have a nice lawn area under your tree.

Hostas (Hosta spp.), English ivy (Hedera helix), ferns, barrenwort (Epimedium spp.), deadnettle (Lamium spp.), sweet woodruff (Galium odoratum), and vinca (Vinca major) are going to be your best friends.

The trees can be planted streetside since they tolerate pollution, though they will probably require pruning to keep those lower branches from blocking traffic or parking areas.

If you choose one of the columnar cultivars, you can use them as a screen or a windbreak.

They also work well for espalier and smaller cultivars can be grown in containers.

Keep in mind that the trees continually drop old leaves as new ones replace them.

That means there will be leaf litter under the tree pretty regularly. You might not want to plant yours next to a patio if you don’t like to do regular cleaning.

You can certainly cut the flowers and use them in arrangements, but don’t forget the foliage. It makes a beautiful addition to an arrangement, and it’s available all year round.

Salt doesn’t faze these trees, so coastal gardeners can enjoy their elegant performance.

They will tolerate areas with exhaust pollution so you can grow them in urban or suburban areas. Just remember, they have extensive roots and can lift sidewalks or driveways.

They also survive hurricanes relatively intact, with perhaps some branch loss, but they tend not to topple over. Thanks to their year-round, dense foliage, as a shade tree, they can help reduce the cost of cooling your home.

So if a magnolia fails to bloom, it’s pretty devastating.

Sometimes, it’s just bad luck, but other times the cause is preventable.

In our guide to growing magnolias, we discuss how to cultivate these trees in the landscape.

This guide is all about the reasons why a magnolia tree may not flower, what you can do about it, if anything, and how to prevent it in the future.

Here are the seven common causes we’ll talk about:

Most magnolias bloom in early spring, but others, like lily (M. lilliflora), M. x loebneri hybrids, and star (M. stellata) magnolias will bloom a second or even third time in the spring or summer. This round is usually smaller than the first one, with fewer flowers.

If a reblooming type doesn’t produce a second flush one year, don’t worry. It’s a sign that the tree may have been stressed for some reason, such as an unusually hot or dry spring. If the next year is better, the tree should rebloom as usual.

Trees that fail to bloom at all are a different matter.

The first common cause we’ll talk about is pretty straightforward and the cure is patience:

1. Age

Flowers are the plant’s method of reproduction, and as with humans, the plant isn’t ready to reproduce until it reaches maturity.

The age that the plant reaches maturity will depend entirely on the particular species, hybrid, or cultivar you are growing.

Some, like saucer magnolias (M. x soulangeana), start young. It’s not unusual to see them blooming when they’re just three years old.

A southern magnolia (M. grandiflora), on the other hand, needs a decade or longer to get started.

If you have a young tree and it has never bloomed before, it’s likely your specimen isn’t mature enough to flower yet – so there’s nothing to worry about.

Add another few years if the magnolia was started from seed.

2. Cold Weather

Frost is the saddest and also the most common cause of a failure to bloom.

My least favorite thing about magnolias is how brief their bloom period is – sometimes, it’s just a week of blossoms in spring. That means 51 weeks of waiting for the big show.

Then, Old Man Winter decides he isn’t done with us, and he blows a chilling frost our way. Magnolia flowers are sensitive to frost.

While the buds can usually survive 32°F and lower, if the temperatures drop below that when the flowers are starting to open, they’re toast. Some years, I notice that those tucked deep into the tree or close to a building survive, but the majority turn into a brown, mushy mess.

There isn’t anything you can do unless your tree is small enough that you can toss some frost cloth over it to provide some protection.

Frost isn’t only a concern when the flowers have opened. Some species, such as banana (M. figo), are sensitive to frost, and cold temperatures when the buds are forming can kill them, and others will even halt flowering the year following a cold winter.

3. Drought

Drought, and particularly dry conditions toward the end of the growing season in the fall, will deprive the tree of the energy it needs to produce flowers.

The blossoms are the tree’s way of reproducing, so when conditions are optimal, they’ll use their energy to produce flowers.

But in times of stress, the tree may need to put all its energy into survival instead of producing blooms.

Adequate water, especially in the fall, is vital. Depending on the species, the ground should be evenly moist at all times.

If nature isn’t providing enough water, get in there and irrigate your trees to keep the soil moist.

4. Fertilizer Problems

Too much nitrogen from overfertilizing is a problem for many reasons. For one, it’s causing serious problems in our water systems.

Second, it causes the accumulation of nitrates in the vegetative tissue. But in relation to your magnolia, it results in excessive leaf growth at the expense of flowering.

You should always test your soil in the spring, or in the fall after most of your plants die back for the year.

Gardeners often waste so much fertilizer feeding when the soil is already full of the nutrients we are adding.

Once you have the results of the test, amend your soil accordingly. You might find that you only need to add phosphorus and not nitrogen or potassium. Or maybe you won’t need to add any nutrients at all.

5. Pruning at the Wrong Time

Magnolias start developing their flower buds well in advance of their actual bloom time, usually in the early fall. So if you prune the trees in the fall, you end up cutting out the developing buds.

This is the easiest issue to prevent, simply do your pruning in the spring or summer, after flowering. Fortunately, most species don’t need much pruning to maintain a nice shape.

In general, I advise not to prune magnolias at all unless absolutely necessary.

These aren’t trees that bounce back readily from a pruning, and I’ve known more than one that never recovered.

Leave them alone unless pruning is needed to remove diseased, damaged, or deformed branches.

6. Stress

If the tree experiences stress during the previous growing season, it might not have the energy to produce flowers the next year. Those blossoms are an energy-intensive business.

Prolonged flooding, pest infestation, or disease, particularly in the fall when the buds are developing, can result in fewer or no flowers.

To avoid this, do your best to support your tree with appropriate care, and watch closely for pests and disease so you can treat them before they stress the tree.

You can learn more about magnolia diseases in our guide.

7. Too Much Shade

Some species are happy in partial shade, while many need full sun to thrive and flower.

M. grandiflora, M. laeviflora, and M. stellata can all grow in part shade. There are also many cultivars that are bred to handle some shade. But generally, these trees do best in full sun.

This can be tricky because most species tolerate some shade when they’re young, but they need full sun as they mature.

That makes sense when you picture their natural environment. Young plants start in the understory of the forest and then grow larger than everything around them, taking up all the sun.

So if we plant magnolias in some shade because they’re happy there when young, but they mature, the trees are then denied the sun they require.

When a magnolia is in too much shade, it won’t bloom.

On a cloudless day, observe your tree and determine how much direct sun it receives. If it isn’t receiving at least eight hours, a lack of sun could be causing the lack of flowers.

You can either plant a new tree in a better location, move your specimen, or prune nearby plants that are blocking sunlight.

In this guide, we’ll discuss 13 common magnolia diseases, and how to identify and treat them, so you can bring your tree back to full health.

Here’s what I’ll cover:

A quick reminder for keeping any plant disease-free: proper and sanitary cultivation is key.

A healthy plant is better at fighting diseases than one that’s already struggling to stay alive. By providing your magnolia with everything it needs to thrive, you’ll also improve the odds that it’ll survive threats to its health.

If you need a refresher on cultivating magnolias, check out our growing guide.

And I know “sanitary” is a bit oxymoronic, since garden work is naturally a dirty endeavor.

But by keeping your gardening implements sterile and being mindful of how pathogens can spread, you’ll be doing your magnolia trees, and other plants in your garden, a huge favor.

1. Algal Leaf Spot

If you didn’t think that algae could afflict land-dwelling trees… think again.

Caused by the parasitic alga Cephaleuros virescens, algal leaf spot spreads by spores that travel via wind and rain to nearby plant surfaces. Multiplying in number, the spores collect in raised blotches or patches on leaf and stem surfaces.

Grayish-green, brown, or orangish in color, these spots cause localized chlorosis, necrosis, and leaf drop, along with overall plant weakness.

The causal algae overwinters in infected foliage and twigs, whether they’re on the plant or on the ground. The following year, the cycle begins anew.

Eliminate possible overwintering sites by raking up nearby plant detritus, and remove spotted leaves and twigs whenever you first notice symptoms.

2. Anthracnose

Caused by species in the Colletotrichum genus of fungi, anthracnose and its symptoms are about as subtle as an open-carried .50-cal revolver at a Texas gas station. Not very.

Overwintering in dead leaves and branches, the spores of the causal pathogen spread via splashing water to nearby foliage, causing large, angular spots near leaf margins.

As the disease progresses, these spots develop a burned look, surrounded by a yellow halo of discoloration.

On upper surfaces of the magnolia foliage, the spots develop blister-like fruiting bodies, which ooze masses of pink spores. Eventually, entire leaves can turn chlorotic yellow and drop.

Foliage should be removed as soon as symptomatic spots are noticed. Nearby leaf and twig detritus should be collected and disposed of, as well.

If the majority of leaves on your magnolia start to become symptomatic, a fungicide program may be needed – look for products containing mancozeb as a main active ingredient.

Bonide Mancozeb Flowable

You can find Bonide’s mancozeb flowable with zinc in 16-ounce concentrate available at Amazon.

Be sure to follow the manufacturer’s directions for application.

3. Bacterial Blight

Blight, noun: a thing that spoils or damages something. In the case of bacterial blight, that sounds about right.

The notable symptoms of bacterial blight – caused by Pseudomonas syringae pv. syringae and Pseudomonas cichorii – are small, dark, necrotic spots, each surrounded by a yellow halo, which slowly expand into blights of larger, more irregular lesions that interfere with plant photosynthesis.

Spreading via wind, insects, or contaminated tools, the causal bacteria enters plants through flower buds and/or wounds, leading to the development of sunken, infected cankers.

Magnolia branches with cankers can exhibit foliar and stem wilt. Oozing dark and sticky fluid, these cankers also act as overwintering sites for the pathogen.

Although typically seen more often in plant nurseries than the landscape, bacterial blight can still be a dangerous threat to your trees.

Prune infected shoots when you notice them, making sure to sterilize your tools between cuts.

If pruning your magnolia doesn’t provide satisfactory control, copper-based bactericides can be used to manage the disease in susceptible environments.

4. Bacterial Leaf Scorch

A systemic, chronic, and incurable disease. Gotta love those.

Bacterial leaf scorch kicks off with Xylella fastidiosa bacteria invading a magnolia tree’s xylem, which is basically a plant’s internal water plumbing.

Overwintering in the xylem year after year, the bacteria can access any and all branches connected to the trunk. Leaves turn brown in midsummer, starting with the older ones and ending with those closest to the branch tips.

Separated from the healthy tissue by a thin yellow border, the brown sections gradually work towards the center of each leaf, eventually causing them to turn entirely brown and drop from the tree.

As years pass, this browning-and-dropping occurs earlier and earlier in the season, weakening and killing parts of the tree in bits and pieces until the entire plant eventually perishes.

As bacterial leaf scorch is spread via xylem-feeding insects such as leafhoppers and spittlebugs, it pays to manage your local pests.

When branches start to turn brown and die off, remove them. If entire trees are in severe decline, remove those as well – you may need to recruit a professional’s help for this.

You can try springtime injections of oxytetracycline antibiotics into the root flare, but those will most likely only reduce bacterium levels enough to delay symptoms by a couple of weeks.

You can consult an arborist if you’re curious, but otherwise, I’d take solace in what J. R. R. Tolkien called “the long defeat,” and remove infected specimens.

5. Bacterial Leaf Spot

Save for the causal pathogens being species of bacteria in the Xanthomonas genus rather than Pseudomonas, bacterial leaf spot causes similar symptoms to those of bacterial blight: dark foliar spots surrounded by faint yellow discoloration, which leads to hindered photosynthesis and reduced aesthetics.

And the “hows” of managing both in magnolias are pretty similar. Prune affected plant tissue and spray with copper-based bactericides in the case of extensive infection.

6. Cankers

We’ve mentioned these already, but they’re definitely harmful and annoying enough to warrant their own entry.

Cankers are necrotic, localized lesions that manifest on the branches, trunks, and/or roots of trees. Often sunken and rounded in appearance, cankers also tend to exhibit discoloration and ooze with gnarly, sticky fluid.

Caused by a variety of different bacterial or fungal pathogens after mechanical or environmental damage, cankers can cause local or systemic dysfunction in foliage and bark. Foliage will turn yellow, brown, and wilted, bark will peel, and plant tissues will die.

As cankers can occur via wounds, it pays to keep your magnolias safe from blades, trimmers, and tree-climbing children.

Prune with caution, give root flares a wide berth when working in the vicinity, and limit Little Timmy’s climbing to the playground until he learns to not peel away bark with his foot placements.

When you notice a canker on a magnolia branch, prune the entire branch. Make your cuts several inches below the canker towards the trunk, to stay on the safe side.

If cankers are on the trunk or roots, I’d recommend you consult with an arborist or plant pathologist – removing those takes skill that’s hard to learn as an amateur. 

7. Crown Gall

I will say, crown galls aren’t as gross as cankers. They are, however, rather honkin’ in size and conspicuous-ness.

Caused by the fun-to-pronounce Agrobacterium tumefaciens, crown galls are essentially tree tumors.

When A. tumefaciens bacteria in nearby soil infects a plant through wounds, it stimulates the plant to produce a large, swollen mass of tissue on trunks, stems, or even roots that provides ample resources for the pathogen to feed on and reproduce in.

This can be harmful to young magnolia plants in particular, as gall development can stunt their growth, inhibit water and nutrient transport, and leave them top-heavy and prone to breakage.

But in older magnolias, the drawbacks of galls are cosmetic and minor.

You can cut out galls during the dry season if you know what you’re doing, or you can recruit someone with more know-how to do it for you.

If the gall takes up a large section of the trunk, you may have to remove the entire tree if its growth is extremely stunted.

You can learn more about crown gall in our guide.

8. Pestalotiopsis Leaf Spot

In case you’re wondering, it’s pronounced pesta-low-she-opsis. I didn’t know the phonetics either, until I looked it up!

Caused by fungal species in the Pestalotiopsis genus, this disease has unique symptoms: circular, necrotic, and black-bordered spots on the foliage.

Inside the black borders, the spots are an orange to tan hue. Take a closer look, and you’ll notice subtle cracking on the surface of necrotic leaf tissues, especially in older spots.

Typically in spring or fall, spores produced by the fruiting body of the fungus spread via wind and water, so it pays to watch your watering, especially during cool and overcast conditions.

Avoid splashing leaves with irrigation, but if you do end up wetting the foliage, water early enough for it to dry before nightfall.

This disease is a little unsightly and hinders photosynthesis, so you should prune infected leaves when you see them.

9. Phytophthora Root Rot

Affecting many different trees and shrubs in the landscape, Phytophthora root rot is no joke. Not that any of these diseases are, but this one falls especially flat, humor-wise.

As moisture-loving water molds (oomycetes), Phytopthora species can survive in soil for years, provided that it stays moist.

The causal pathogen spreads primarily via water, such as splashing rain, irrigation, or runoff – but can also travel via contaminated soils and garden tools.

It favors the cool and rainy weather of early spring and late fall, and doesn’t require a wound or other damage to gain entry to plant tissues.

Infection in magnolias causes the foliage to wilt, lose its vibrant color, and otherwise appear drought-stressed.

The tree bark at soil level will typically look unusually dark, and the wood underneath it will appear an unhealthy-looking reddish-brown. After a few years of declining health and putting up a fight, infected trees will most likely perish.

Make sure that your soil is very well-draining prior to planting. If you’d like, planting on a raised mound of soil can help keep water from pooling up around the roots. But make sure that the root flare of your magnolia trees are exposed!

Once the magnolia is in the ground and growing, don’t overwater, and ensure you plant in well-draining soil.

If an infected tree becomes heavily diseased and/or more trouble than it’s worth, remove it – along with the soil within the root zone – and replace it with a resistant tree such as arborvitae, elm, or ginkgo.

10. Phyllosticta Leaf Spot

A particular foe of the southern magnolia, M. grandiflora, Phyllosticta leaf spot is a fungal condition caused by Phyllosticta magnoliae.

When a pathogen is named after a plant it infects, you know that it’s an epic rivalry.

Overwintering on nearby fallen plant detritus, the fungus spreads to new leaves in spring via splashing water.

On the upper surfaces of new foliage, small purplish-black lesions form, eventually growing in size and manifesting dirty white centers while surrounded by chlorotic halos of yellow.

As with any leaf spot disease, photosynthesis is reduced and the tree’s health may suffer if the damage is extensive.

Wet, humid conditions promote disease spread, so avoid wetting the foliage and watering late in the day. If you notice any spotted leaves, remove them.

If this disease ends up infecting most of the canopy of your magnolia and becoming a bigger problem than pruning can fix, early-season applications of copper fungicides can help prevent it and limit its spread.

11. Powdery Mildew

It’s kinda nice when the name of a disease lets you know its symptoms. Exhibit A: powdery mildew.

In magnolias, the causal fungus is usually either Microsphaera penicillata or Phyllactinia corylea.

Spreading by wind in spring to early summer, the spores cause white powdery patches to form on upper surfaces of foliage, which can lead to curled leaves and stunted growth overall.

A particular problem when days are warm to hot and nights are cool and dewey, this disease overwinters as fungal mycelium in dormant buds or as spores on fallen leaves.

Properly prune your magnolia tree canopy to allow for airflow to dry the foliage. If you notice severely mildewy foliage and branches, cut them right away. 

12. Verticillium Wilt

When it comes to killing your beloved magnolia trees, Verticillium wilt doesn’t waste time. The one time you wouldn’t mind a little dilly-dallying…

Verticillium wilt kicks off with the invasion of fungal Verticillium species such as V. albo-atrum or V. dahlia into a tree’s wounded roots.

You can tell you’re dealing with Verticillium wilt by a general browning of the inner sapwood, should you cut away a stem’s bark to take a look.

This infection clogs up the vascular tissues and leads to leaf and branch dieback, typically on one side of the plant.

The stress of the disease allows for opportunistic fungi to invade the tree, tag teaming it into further decline. In a year or two, the plant will most likely die.

The causal fungi live in soil and spread via wind, soil disturbance, and gardening tools.

Stressed-out roots allow for the the pathogen to enter the magnolia, so be sure to water properly – not too much, not too little – and be careful not to accidentally wound the tree with pruning tools, weed whackers, or runaway lawn mowers.

I hate to say it, but if your trees are sick, remove ’em and replace them with more resistant trees such as oaks, conifers, or dogwoods.

13. Wetwood

I bet you can guess wetwood’s signature symptom.

Also known as slime flux, wetwood is caused by the ingress of various bacteria into tree wounds, primarily those in the roots.

Bacterial fermentation produces gaseous and liquid byproducts, which leads to an ooze of dark liquid from tree crotches, bark cracks, and pruning wounds that reaches its peak in summertime.

This gross liquid also moves within a plant, causing wilting, defoliation, branch dieback, and reduced vigor. Thankfully, plant death is a rare occurrence.

Aside from avoiding wounds and removing severely symptomatic branches, not much can be done about wetwood. It’s kinda like the runny nose of magnolia trees, if that’s any consolation.

Why would you want a tree that goes bare in the winter if you don’t have to? Deciduous magnolias are more versatile in the garden, for one.

They come in smaller sizes, there are those that can survive in swampy conditions, and there are some with even larger, showier blossoms than the good old Southern type as well.

Plus, since they lose their leaves each year, those in regions that receive snow won’t have to deal with the branches being weighed down and breaking nearly as often.

It’s about time these lesser-known trees got their time in the spotlight. Move over, Southern magnolia! We’re focusing on deciduous magnolias today.

Here are the beauties we’ll talk about in this roundup:

There are around 40 species of deciduous magnolias, and this number includes many garden favorites.

The bigleaf (M. macrophylla), Campbell’s (M. campbellii), cucumber (M. acuminata), Fraser (M. fraseri), lily (M. liliiflora), Sprenger’s (M. sprengeri), star (M. stellata), sweetbay (M. virginiana), umbrella (M. tripetala), and Yulan (M. denudata) and their hybrids are the ones you most commonly see on the commercial market.

Regardless of which you choose, they have fairly similar growing requirements. Learn about growing magnolias in our guide if you need some tips.

To start with, we’ll discuss a cultivar from the Little Girl series, one which has become a mainstay in gardens:

1. Ann

‘Ann’ was bred from M. liliiflora ‘Nigra,’ a small tree with deep purple blossoms, and M. stellata ‘Rosea,’ a larger tree with star-like pink blossoms that fade to white.

The result is a small tree, under 12 feet tall and 15 feet wide, that flowers later in the spring to dodge most late frosts. She might even give you a second round of blossoms in the summer if there’s enough moisture.

That makes them the largest of a single-leaf deciduous tree native to North America. In warmer climates, these trees can be semi-evergreen.

They don’t sacrifice flowers for leaf size, though. The blossoms can be a full foot and a half in diameter. When it comes to non-tropical flowers, they’re the largest in the world.

Really, nothing about this tree is small. While it isn’t the tallest magnolia, it can grow up to 65 feet in the forest understory environment that it prefers.

It takes a long time for this tree to mature to the point where the white and purple flowers appear, at least 12 years.

Sadly, it can be a beast to keep happy in the garden. It needs super loose, well-draining soil, a perfect balance of sun and shade, and consistent moisture.

While it isn’t usually troubled by pests or disease, any extreme variation in moisture and temperature will shorten its life considerably. But many of its hybrids have the dramatically-sized leaves and flowers combined with a more forgiving nature.

Oh, and buy a big, sturdy rake along with your tree, if you decide to plant one of these. You haven’t seen fallen leaves until you have to rake up after your bigleaf!

Bigleafs can grow in USDA Hardiness Zones 5b to 9b.

3. Butterflies

Beautiful ‘Butterflies’ is a cross between M. acuminata ‘Fertile Myrtle’ and M. denudata ‘Sawada’s Cream.’

The leaves are dark green on top and pale green underneath.

One of the drawbacks of this tree is that late frosts will kill the flowers if it’s planted in a region that has them, though the subspecies mollicomata flowers a bit later in the year, so it might dodge this issue.

The species has also been used to create numerous beloved late-flowering hybrids and there are several beautiful cultivars like ‘Alba’ and ‘Strybing White,’ with pure white blossoms, and ‘Lanarth,’ with massive deep violet flowers.

The species grows best in Zones 7 to 10.

5. Cucumber

Cucumber trees, M. acuminata, aren’t really adored for their flowers, which are small, greenish-yellow, and appear high up in the tree where they can be difficult to see.

They’re valued for their huge leaves, which grow up to nine inches long with an attractive, open shape.

The foliage takes on a golden hue in autumn, unusual for magnolias which usually lack striking fall foliage.

While it might not be wildly popular on its own, this North American native has been used to create many popular hybrids.

These majestic trees can grow up to 70 feet tall with a pyramidal shape. It takes over a decade before they start to produce their slightly fragrant flowers, and fruits which look like tiny cucumbers.

This species is also adaptable, happy in Zones 4 to 8.

6. Daybreak

A cross between M. ‘Woodsman’ and likely M. ‘Tina Durio,’ ‘Daybreak’ was created by plant geneticist and breeder Dr. August Kehr and released in 1990.

It quickly became a popular option on the market and nabbed the Pennsylvania Horticultural Society’s Gold Medal in 2004, and the Royal Horticultural Society’s Award of Garden Merit in 2012.

Part of what makes this such a nice tree is that it has a columnar shape, which is uncommon in magnolias. It grows to about 25 feet tall and half as wide.

The rose-pink flowers are huge, up to 10 inches across, and come out late enough that they can usually avoid blossom-killing frosts.

This tree is tolerant of pollution which, combined with its compact growth, makes it a smart option for planting near roadways or in parking strips in Zones 5 to 8.

7. Fraser

Mountain or Fraser magnolias (M. fraseri) are native to the southeastern US ranging from Florida as far north as West Virginia, and west as far as Texas.

They stick primarily to the Appalachian Mountain Range.

These are some of the smaller magnolias, rarely topping 40 feet. The leaves can be relatively large at around 12 inches long, but they can reach a foot and a half. The flowers are about nine inches wide and they’re creamy white.

When the leaves fall from the tree, you can really get a good look at the scaly brown bark, which adds texture to the landscape.

This species doesn’t tolerate temperatures as cold as some others in the genus. It’s generally restricted to growing in Zones 8b to 10b.

8. Galaxy

Bred by the US National Arboretum in 1963, ‘Galaxy’ is a hybrid cross between M. liliiflora ‘Nigra’ and M. sprengeri ‘Diva.’

It grows to about 30 feet tall with a pyramidal shape. When young, it’s quite narrow, though it will gradually spread – as so many of us do – when it hits middle age.

The flowers open later in the year to dodge sneaky frosts in Zones 5 to 9.

Once they do, you’re treated to a galaxy of reddish-purple, 10-inch blossoms, followed by medium and light green leaves that are attractive all on their own.

Plus, it blooms while still quite young, around nine years old.

This cultivar is so nice it nabbed the Pennsylvania Horticultural Society’s Gold Medal in 1992 and the Royal Horticultural Society’s Award of Garden Merit in 1993.

9. Goldfinch

Gorgeous ‘Goldfinch’ (or ‘Gold Finch’) has pale yellow blossoms that emerge late in the spring to dodge those surprise late frosts.

It’s also one of the cold-hardiest yellow types, and the tree blooms younger than many others, so you don’t have to wait as long for the show.

It was bred by renowned hybridizer Phil Savage, Jr. in Michigan.

He used M. acuminata ‘Miss Honeybee’ and M. denudata ‘Sawada’s Cream’ to create a tree with an open, spreading habit in a compact 15-foot tall height with goblet-shaped, 10-inch-wide flowers.

Plant it in Zones 4 to 8.

10. Jane

Many magnolias lose their flowers if a late freeze happens along, as we’ve noted.

It is widely cultivated across Asia, Europe, and North America.

Magnolia liliiflora ‘Nigra’ or Black lily magnolia tree. Ornamental tree with opulent upright reddish-purple to gorgeous pink tulip-shaped flowers and its deep, glowing green leaves.

Known variously as red, purple, lily, tulip, Mulan, and Japanese magnolia, its petite height, at under 15 feet tall and wide, and its profuse, lily-shaped blossoms, have made it extremely popular as a parent for hybridizing.

The famous saucer magnolia, which we’ll cover next, was bred by crossing this tree and M. denudata.

As with most magnolias on this list, the blossoms appear in the spring before the foliage emerges, but this species and some of its hybrids might also have a smaller repeat bloom in midsummer.

While it isn’t as widely known as some of its offspring, lily magnolias would be perfect for those who have a small area for planting in Zones 5 to 9 and want something floriferous even in partial shade.

12. Saucer

Saucer magnolias (M. x soulangeana) were bred by hybridizing M. denudata and M. liliflora.

They are famous for their huge, five- to 10-inch blossoms that emerge early in spring. So early, in fact, that they are often killed off by a late frost, which can be a huge bummer.

15. Umbrella

The umbrella tree or umbrella magnolia (M. tripetala) gets its name from the shiny leaves, which cluster in a circle at the end of the stems.

You could easily see them functioning as an umbrella for a garden gnome.

Native to the Appalachian region, it grows in the forest understory, rarely reaching more than 40 feet tall.

It’s not cultivated for its large white and green flowers, pretty though they are. It’s primarily appreciated as a shade tree, though the colorful purple and red fruits are worth a second look.

Beyond lacking the striking floral show that so many people love, the flowers also kind of stink.

So the umbrella tree has found its niche in the world of cultivation as a parent for some beautiful hybrids. The species is hardy in Zones 5a to 8b.