Tag: Christmas Cactus

Plants that come into our homes from commercial greenhouses have been grown in exacting conditions that few of us can replicate.

And ones that come indoors from spending the summer out in the garden also have to adjust to changes in humidity, light, moisture, and temperature.

A few dropped buds can be expected as plants acclimate to a new environment, but with a little forethought to their needs, bud drop is easy to minimize and even eliminate!

Are you ready to enjoy an exuberant floral display this holiday season? Then let’s unwrap the steps on how to prevent Christmas cactus bud drop.

Here’s what you’ll find ahead:

Favorable Lighting

Native to the coastal mountains of Brazil, Schlumbergera species and hybrids are indigenous to tropical rainforests where they grow on tree branches and rocks in filtered sunlight.

As houseplants, they do best with indirect light of bright or medium intensity.

This makes east-, north-, and west-facing windows the best choice.

South- and south-west-facing windows should be avoided as hot, direct sunlight can cause sunburn and scorching to the stems as well as dropped buds.

You can learn more about Christmas cactus care in our growing guide.

When in bud, these short-day plants need to receive around 14 hours of darkness each night. You can learn more about how to encourage them to bloom in our guide.

Placing them in a room with bright, artificial light that stays on long after sundown can also cause buds to drop. Instead, place them in a location where overhead lights can be turned off or dimmed in the evening.

Keep Things Cool

As much as possible, try to mimic the climate of their greenhouse environment – which in turn, mimics their native habitat’s late fall weather of cool evenings and warm days.

Overnight temperatures of 55 to 65°F are ideal with daytime highs of up to 80°F.

In your home, aim for a range of 70 to 80°F and avoid hot rooms with poor air circulation – temperatures over 90°F are problematic for maintaining blooms.

Also, don’t place your plants close to cooling and heating vents or drafty doors and windows – cold or hot blowing air is another reason for bud drop.

And if your plants spend summer and early fall outdoors, be sure to bring them in before the first frost as icy temperatures are another cause of falling flowers. Get the scoop on outdoor care here.

Humidity and Water

These rainforest natives love humidity but they don’t appreciate wet feet.

Overly wet roots or irregular watering when budding or in bloom are a couple of additional stressors that can cause flower loss.

Although holiday cactus can handle dryish conditions for most of the year, when setting buds and when in bloom, consistently moist soil is important, but wet soil needs to be avoided.

Check out our guide to saving an overwatered Christmas cactus if this is a problem for you.

Allow the top one inch of soil to dry out between water applications.

Bottom watering in a sink or tub of water is the preferred method for Schlumbergera, but moving them when they’re ready to flower, or in bloom, isn’t recommended.

Instead, water slowly just until the liquid emerges from the bottom of the pot into a catchment saucer. Allow the soil to reabsorb water for up to an hour, discarding any that remains in the saucer after that.

Mist lightly on a weekly basis to provide the humidity they like.

If the winter air in your home is very dry, try placing your potted cactus on a shallow bowl of pebbles and water.

As the water evaporates, it envelops your plant in moist air. But don’t nestle the pot into the pebbles – keep its base on top of the stones and above the water line to prevent wet soil which can lead to root rot.

Hold the Feed

Holiday cacti are light to moderate feeders and can suffer when overfertilized.

Providing too much nutrition can burn the roots with mineral salt buildup and can also produce  an excessive number of buds, with several on a single stem tip.

Too many nascent flowers can cause some to drop off in order to provide room for others to develop fully.

Suspend fertilizing in late summer and only resume feeding plants when the new growth cycle resumes in spring.

For feeding details, check out how and when to fertilize Christmas cactus in our guide.

Holiday cacti will drop their cladodes – the leaflike structures – naturally as they age. It’s usually just one or two here and there, and the plant will look perfectly healthy otherwise.

Speaking of, check out our guide to growing Christmas cactus to learn what it takes to keep your specimen in good shape.

But if young leaves are falling or more than a few are dropping at a time, you need to read this guide and figure out what’s going on.

Here’s the list of issues we’ll go over:

The first topic we’ll discuss is probably one of the least common unless you are a chronic overwaterer.

1. Disease

If the cladodes are falling and you notice little tan lesions or black water-soaked spots on the foliage, you’re probably dealing with Fusarium wilt, caused by the fungus Fusarium oxysporum.

This pathogen needs a lot of moisture to thrive and spread, so overwatering or keeping your plant in poorly draining soil or containers can invite it.

You might be able to save the specimen if you catch it early enough, but if not, your best bet is to take a cutting to propagate a new plant and toss the infected one.

2. Inappropriate Temperature

Anytime they are exposed to temperatures above 90°F or below 50°F, you run the risk of flower buds or leaves dropping.

Don’t assume that you’re safe just because you keep your home at a moderate temperature.

If your Christmas cactus is situated next to a single-pane window or an exterior door, it could be exposed to extreme temperatures often enough to cause problems.

Single pane windows don’t provide much insulation, which means they get hot during the heat of summer and they let in a lot of cold during the chilly winter days.

If you live in an area that experiences particularly frigid winters or sweltering summers, keep your Christmas cactus away from windows and doors.

Anywhere toward the interior of the house with supplemental lighting or skylights, or near well-insulated, multi-pane windows is fine.

3. Not Enough Light

Yes, they’re houseplants, and they can survive in the same light we have in our homes.

But Christmas cacti thrive in direct sunlight in the fall and winter, and direct light in the morning followed by bright, indirect light the rest of the day in spring and summer.

Anything less than that, and you run the risk that the plants will drop their cladodes.

If insufficient light is the cause, the plant will also be etiolated, which means it will be paler than it should be if it was kept in the correct exposure.

The fix for this cause is easy: move it into a spot with brighter light!

4. Nutrient Deficiency

I wouldn’t call Christmas cacti particularly greedy, but even if you’ve been feeding regularly, if the soil is old and depleted, your Christmas cactus might not be able to access the nutrients it needs.

You should be fertilizing your plant regularly starting in late winter or early spring. As soon as you see new growth developing, that’s when you need to start feeding.

Use a 10-10-10 or 20-20-20 NPK fertilizer once a month until fall.

Two weeks after you apply the fertilizer, add a teaspoon of Epsom salt dissolved in a gallon of water to add magnesium to the soil.

Holiday cacti are greedy for magnesium. Provide the typical amount of water you normally use and set aside any excess solution. It will last for several weeks.

Learn more about how to fertilize Christmas cacti in our guide.

If you haven’t replenished the soil in the past five years or so, remove the plant from its pot and brush away all the soil.

Repot with fresh, new potting soil. Not sure what potting soil to use? Check out our comprehensive guide.

5. Pests

Sap-sucking pests like aphids, spider mites, and mealybugs can drain the plants enough that they might start dropping their leaves.

Before this happens, you’ll notice other symptoms like yellowing leaves and a sticky substance on the foliage known as honeydew.

Visit our guide to Christmas cactus pests to learn about identifying insect problems and how to get rid of them.

6. Too Little Water

It’s harder to underwater these plants than it is to overwater them. The paddle-like, succulent leaves store water well.

But if they go long enough without water, the cladodes will start to shrivel up, turn yellow or brown, and fall. The entire specimen will appear droopy, as well.

This probably won’t happen if you forget to water one time, but chronic underwatering will cause it.

The solution, of course, is to stay on top of your watering schedule while making sure you aren’t overwatering, which we’ll talk about next.

7. Too Much Water

It’s surprisingly easy to overwater a Christmas cactus, and when you do, leaf drop is sure to follow.

When you overwater, the roots in the soil basically drown. They can’t access oxygen, and they start to rot away. Aboveground, that means the plant can’t support its cladodes, and they get ejected.

Holiday cacti are true cacti, but they like a good amount of moisture, unlike their desert-dwelling cousins.

You should be allowing the surface of the soil to dry out before you add more moisture. When the plant isn’t blooming, you can leave it until the top half-inch of soil dries out.

The easiest way to avoid overwatering is to mount the plant on wood or wire. As epiphytes, they grow well this way, and it’s almost impossible to overwater mounted specimens.

If you’ve never mounted a plant before, it involves wrapping the roots in moss and fastening the plant to wood or wire to recreate the natural environment that epiphytes thrive in.

For information about how to rescue an overwatered Christmas cactus, head on over to our guide.

It gave me a boost then and now, and I have one in my home all the time for the cheerful inspiration it gives me just as I’m considering a move to the tropics.

I can totally understand how these plants are so popular in the Northern Hemisphere, far from their original home in Brazil.

So enough about me. I’m sure you have your own love story with these plants and are just wondering what makes one different from the other.

All of the plants commonly known as holiday cacti are epiphytes or in rare cases lithophytes, which means they grow on other trees or shrubs, and sometimes rocks.

They aren’t parasites, though, drawing energy from a host. They just use the host as a support, deriving nutrients from the debris and rain that comes down through the rainforest canopy.

All types of holiday cacti species are from the Brazilian rainforests in high elevations, and they share many similar physical characteristics.

If you aren’t familiar with the subtle nuances, they all look extremely similar, so you can see why they are grouped together under the term “holiday cactus.”

But included in this moniker there are many different species, hybrids, and cultivars, all with their own unique shapes, bloom time, and colors. It just takes some time to cut through the confusion out there about them.

We’re going to make it all clear as we talk about the different holiday cactus varieties.

Here’s what I’ll cover:

Before we talk about the different types, we need to clarify our terms so we’re on the same page.

The leaf-like structures on the plants that hold the flowers aren’t actually leaves at all.

If the plant forms leaves, these are typically inconspicuous and brown or green in color. The flattened, leaf-like parts are actually segmented stems known as cladodes or phylloclades.

Looking closely at the cladodes will help you determine broadly which type you’re dealing with.

Along the margins of the cladodes are little horns, spikes, or teeth, which is a type of growth known as “dentate.”

The flowers emerge at the end of the cladodes from growths known as areoles, and it is this growth that defines these as true cacti rather than succulents.

This is a confusing group of plants if you ask retailers and botanists.

Those commonly referred to as Thanksgiving cactus are sometimes sold as Christmas, and vice versa; and often the hybrids are sold under the “Christmas” or “Thanksgiving” moniker as well.

Easter types might be sold as “holiday” and any hybrid using an Easter species might be classified as a Thanksgiving or Christmas.

Basically, it’s hard to identify them based on the common names.

Broadly, you can assume that the plants are categorized by when they bloom, but that’s not always the case – “Christmas” tends to be a catch-all term.

S. kautskyi, for example, blooms in late summer but is commonly called Christmas cactus.

Then, there is the sorting of the genera. All of the holiday cacti plants used to be classified as species in the Schlumbergera genus, but many have since been shuffled around into the Hatiora or Rhipsalidopsis genera.

Unless you check out the botanical name, you might have a hard time telling which one you’re buying when you’re out shopping, and the botanical name isn’t always listed.

Most of the plants that you find in stores are hybrids, usually between S. russelliana and S. truncata, known as S. x buckleyi.

So, now that we’ve really muddied the waters, let’s filter through the info.

1. Christmas

S. x buckleyi is what experts consider the true Christmas cactus. It’s a hybrid cross of S. russelliana and S. truncata, and all of the plants are sterile, so you can’t propagate them from seed.

Remember the plant bedstemor grew that sparked my interest? It’s highly likely that it was one of these.

It was originally cultivated in 1852 by breeder William Buckley at the Rollisson Nurseries in England. Since then, cuttings have been used to propagate the majority of new plants, and it has become the one that you will typically find in stores.

The cladodes are long and smooth with gently scalloped edges, and the plant blooms in late November through February, which is why we call it the Christmas cactus. The flowers are usually red or magenta, but some are expanding beyond these hues.

S. kautskyi was discovered in 1991 in the southernmost tropics of Brazil, so it is only now catching on in the commercial market.

It has cladodes with short teeth that end in a blunt edge rather than a pointed tip. The segments vary dramatically in length, lacking the uniformity of some species.

The flowers are purple to fuchsia and appear before any other species. They begin popping up in late summer and last through November – not at Christmastime at all!

Native to the tropical mountains of southeastern Brazil, S. orssichiana isn’t commonly seen growing as a houseplant, but hybrids of it are.

This species has pink flowers held somewhat vertically and they can appear three times each year, starting in late summer, again in early winter, and finally in early spring. It has spiked phylloclades, similar to those of S. truncata.

As one of the primary parent plants of many of the holiday cacti on the market, you’ve probably seen S. russelliana and didn’t realize it.

The flowers, which hang downwards, are bright pinkish-red and appear later than most other species in the Schlumbergera genus.

You’ll typically see them appear in February to April, though they can persist through June.

In the wild, this species only appears in a tiny part of southeastern Brazil in the mountains.

S. russelliana can be identified by the irregularly and subtly notched edges of the rounded cladodes and the large, long, pinkish-red flowers with curving petals.

Formerly known as S. bridgesii, you will often see it listed under this name.

It tends to have a pendulous growth habit and blooms longer than the hybrid (S. x. buckleyi) that is considered the true Christmas cactus.

2. Easter

Easter cactus, Rhipsalidopsis gaertneri, (syn. S. gaertneri, H. gaertneri) is an outlier. Its taxonomy is unsettled, and it has been reclassified several times in recent decades.

Sometimes called Whitsun cactus, this species indigenous to the southeastern Brazil rainforest and blooms late in the holiday season.

It doesn’t look entirely different from those in the Schlumbergera genus. In fact, to the uninitiated, it looks pretty darn similar. The spring blossoms can be red, orange, or white and are star-shaped rather than tubular.

To differentiate this one from the other types, look for the rounded cladodes. These sometimes have golden-brown bristles at the end. These bristles are the leaves of the plant.

R. rosea (syn. H. rosea and S. rosea) is a parent of many Easter hybrids and is sometimes called the dwarf or rose Easter cactus.

It’s a repeat bloomer, typically starting in the early spring and reblooming in the fall.

It’s closely related to the Easter species (R. gaertneri) and comes from the same region of Brazil.

The flowers, which appear around Easter, are rose pink and extremely fragrant. The phylloclades are gently scalloped.

3. Thanksgiving

S. truncata is typically known as Thanksgiving cactus because of the period when it blooms. You might also see it called “false” Christmas cactus, crab, or Christmas cactus.

The pink, orange, or white flowers appear right around the time when people are defrosting their turkeys, mashing up potatoes, and setting up cardboard tables for the kids to sit at.

It might bloom a second time in February if it’s really happy.

You can distinguish this one by its pointed teeth at the tips of the cladodes. The shape is often compared to a crab claw, though it doesn’t always have the two large teeth at the end that create this resemblance. It might just have one, or it might have three.

Most cultivars have flowers that are held horizontally, which is how the species plant appears.

4. Other Holiday Species

S. lutea (syn. H. epiphylloides) isn’t like the others. I mean, it’s the same in that if you saw it sitting in a room with a bunch of other holiday cacti, you probably couldn’t call it out.

Except for the gorgeous yellow flowers. While most holiday cacti have blossoms in red or purple hues, this one is sunny yellow.

Hailing from southeast Brazil, there are two subspecies: lutea and bradei.

They have elongated phylloclades with gently toothed margins and a subtle triangular shape.

S. x reginae is a hybrid between S. orssichiana, which hails from the mountains of southern Brazil, and S. truncata.

This one breaks with the typical holiday naming tradition. It’s sometimes called queen cactus and is recognized for its elongated phylloclades with distinct teeth on the margins.

The weeping blossoms, which appear in late fall, are pinky-purple and might have some white.

These aren’t widely available, but specialty retailers are starting to carry some beautiful cultivars such as ‘Dark Queen,’ with its blood-red blossoms, and fuchsia-flowered ‘Bristol Queen,’ the first one to be available commercially.

These are considered a bit fussier and more difficult to raise than some of the more commonly available specimens.

And while they’re easy to care for, encouraging them to bloom again can be a bit difficult.

That’s because they have specific requirements to induce bud set and flowering. It’s all about the timing of daylight to dark hours, plus knowing when to fertilize and when to stop feeding.

If you’re ready for a fantastic flowering succulent this winter, let’s unwrap the steps on how to feed a Christmas cactus.

Here’s what I’ll cover:

Holiday Cactus Basics

Christmas and Thanksgiving cacti are epiphytes in the genus Schlumbergera, native to tropical rainforests of Brazil.

Ideal houseplants, they’re easy to care for and thrive in bright, indirect light in well-draining soil with a slightly acidic pH of 5.7 to 6.5, and average moisture.

Bud set occurs during the cooler days of fall when the dark of night lengthens noticeably.

This is because holiday cactus are short day/long night plants. Like chrysanthemums and poinsettias, their photoperiodic response for flowering occurs when day length dwindles to 12 hours or less and temperatures cool off.

If you put your plants outside for part of the growing season, bud set occurs naturally, starting around the middle of September, depending on your region.

Then, when they’re brought in before the first frost, flowering occurs shortly afterwards – mine are always in full bloom for Halloween!

To time your flowering for later in the season, such as between Thanksgiving and Christmas, you may have to manipulate them with a false dormancy.

This is done primarily by artificially reducing daylight hours to eight to 10 hours per day.

If you’d like more info, dig into the easy steps in our guide to encouraging your Christmas cactus to bloom.

Along with light, moisture, and temperature, a steady supply of nutrients is needed to support overall plant health and full flowering.

When and How to Feed

To promote strong, healthy plants with an abundant bud set, fertilize your Christmas cactus during the growing season of spring and summer, or roughly from the start of March to mid-September.

Once the days start to lengthen in early spring and new growth is emerging, this is the time to begin fertilizing your plants.

To meet their nutritional requirements, feed them monthly with a half-strength solution of a balanced liquid formula such as 10-10-10 (NPK).

Experts at the University of Georgia Extension program also suggest supplementing your plants during the growing season with magnesium sulfate, aka Epsom salts – but you’ll need to use a light touch.

Mix only one teaspoon of Epsom salts into one gallon of water and apply monthly.

Alternate feeding with the Epsom salts and balanced fertilizer so they’re applied two weeks apart – avoid applying them at the same time.

Depending on the size of your Christmas cactus and the pot it’s growing in, gently work in one to two inches of compost or castings in early spring and again in midsummer.

Once the buds appear, withhold feeding until winter is over. The plants aren’t actively growing at this time and need a dormant period to rest and re-energize for another flowering season.

Leach the Soil

Regular fertilization can cause a buildup of mineral salts in the soil and this can cause damage to your plants’ roots. Leaching the soil can help prevent this.

Leach the soil after your plant has finished flowering by placing the pot in a sink or bucket and watering normally, using the same amount of water as you would during the growing season.

To avoid adding more minerals to the mix, use distilled, filtered, or rainwater if possible.

Wait five minutes to allow the salts in the soil to dissolve, then re-water, once again using the same amount of water as you would in your regular applications.

The second application should cause water containing the dissolved salts to flow from the bottom of the container, cleansing the soil and reinvigorating your plants. Discard the expelled water.