Tag: Pansies

I’ll even pop one of the edible flowers onto my salad now and then to cheer up my winter meals.

These plants are resilient enough to survive and even keep blooming through a heavy freeze. They can often perk back up after being buried in snow for a few days. They’re a lot tougher than they look.

But then summer rolls around, and the plants don’t always look so healthy. Heat is their Achilles heel.

In our guide to growing pansies, we cover how to cultivate these colorful, easy-care flowers in your garden.

This guide explains what kind of temperatures species in the Viola genus can tolerate, what to do with your plants during the warm weather, and we’ll even offer up a few options that will tolerate a bit more heat than most.

Here’s what I’ll cover:

What Temperatures Do Pansies Prefer?

Pansies, violets, and violas are much happier on the cooler end of the temperature scale than in heat.

Depending on the cultivar, they can survive down to 15°F, though most will suffer some cold damage or stop blooming when temperatures drop below about 25°F.

This damage primarily comes from the roots being unable to take up water when the soil is frozen rather than the freezing temperatures themselves.

You might see the leaves and flowers turning mushy if the plant is suffering from freeze damage.

On the other end of the scale, when the temperature starts to creep into the mid-70s, the plants begin to go dormant.

Species in the Viola genus are known as facultative long-day plants, which means that they are influenced to bloom by the number of daylight hours but they will still bloom any time of year regardless of daylight hours.

They just flower more rapidly and abundantly when the number of daylight hours is 14 or over.

What this tells us is that the number of daylight hours promotes blooming but it’s the temperature that causes them to stop flowering, not the arrival of summer.

If the temperatures stay cool longer than normal, or turn hot earlier than normal, the flowering will be influenced.

Learn more about when pansies bloom in our guide.

You might have noticed that violets become long and leggy during the longer days. That’s because the flowers fade more quickly without giving the plant time to develop lateral shoots.

One day of high temperatures won’t hurt them. It’s when the conditions are hot day after day that things get dicey.

Whether they flower or not also depends on how much the summer temperatures drop at night. It’s the average temperature measured over 24 hours that is important.

Let’s say the temperature climbs to 90°F during the day, but it drops to 45°F at night. That makes the average around 67°F, which is low enough to keep the plants happy.

On the other hand, if it’s 95°F during the day and 65 at night, the average is 80°F. That’s too hot for pansies.

So whether your flowers are happy or not might depend more on the nighttime temperatures in your region than the heat of the day.

How to Care for Pansies in Summer

When the weather starts to warm up, you might be tempted to dramatically increase the amount of water you’re giving your plants, but this isn’t a good idea, as they enter a dormant state and the roots won’t absorb as much water.

Just keep watering them consistently so the soil remains evenly moist but not waterlogged. It’s very easy to overwater and cause root rot.

On the other hand, not enough water will cause your plants to dry out and eventually die. So try to keep the amount of water consistent throughout the year.

You can cover your plants with shade cloth to shield them from the heat of the day and the afternoon sun, this will help keep the temperatures around them a bit lower.

Many gardeners treat their pansies as annuals and just toss them out when the weather gets too hot, and that’s certainly an option.

You can keep your pansies in place, providing consistent water and a bit of shade, and most will survive unless it is extremely hot and sunny. They just won’t bloom.

I keep mine during the summer and they stop blooming when the temperatures are consistently above 80°F, but the greens stick around.

Then, in the fall, when the temperatures start to drop, they pick back up – but I live in a region with relatively mild summers.

Even if you do live somewhere that experiences very hot summers, if you plan ahead and put your plants in a spot that is protected from direct sun in the afternoon, yours should be fine.

They’ll start blooming again when the weather cools off a bit in autumn.

As the temperatures start to rise, trim back any remaining or spent flowers and pinch the plants back a bit to remove any leggy growth.

Go ahead and surround them with other low-growing summer annuals to jazz up the area.

If you have a plant that you adore and you don’t want to give up on it, you can also bring it indoors to grow as a houseplant during the hottest time of year.

The climate in your home is probably a lot cooler than the great outdoors. Just make sure the plant receives plenty of direct light.

Cultural requirements include organically rich, moist, well-draining soil and a location with full sun to partial shade.

Our guide to growing pansies has all you need to know to enjoy plants in your outdoor living space.

This article discusses nine pests you may encounter while you are growing pansies, including their physical characteristics, avoidance measures, and treatment options.

Here’s what we’ll cover:

Let’s get ready to battle these bugs!

While pansies are not especially prone to pests, factors like moisture stress and proximity to affected plants may make them vulnerable to infestation.

In addition to causing disfigured foliage, insects that feed on pansies may carry diseases that cause severe damage and even plant death. Let’s look at nine of the most common culprits.

1. Aphids

Aphids are soft-bodied sapsuckers that destroy plant tissue with their chewing mouthparts, secreting toxins that disfigure foliage, causing it to become misshapen, yellow, and stunted.

In addition, their sticky excrement known as honeydew is a perfect breeding ground for a fungal condition called sooty mold.

Cultural Controls

Avoid overfertilizing your pansies and the use of high nitrogen products that promote overly lush foliage attractive to aphids.

Inhibit stressors like too much or too little water that render pansy plants more vulnerable to attack.

Interplant pansies with aromatic herbs like dill and fennel that can deter aphids.

Keep the weeds down to avoid increasing the number of available host plants.

Lay silver mulch around plants. The reflective surface acts as an effective deterrent.

Space plants generously to avoid increasing the ambient humidity around plants which may promote the development of fungal disease.

Synthetic organophosphate insecticides such as acephate and malathion may prove effective but are toxic to bees, beneficials that may feed on aphids, marine life, pets, and people.

Synthetic pyrethroid insecticides containing permethrin, cyfluthrin, or bifenthrin may be an effective last resort.

Pyrethroids are synthetic products that simulate the naturally occurring pyrethrins in chrysanthemums. Unfortunately, they are toxic to marine life, people, pets, and beneficial insects, including bees.

See our guide to aphids for more information.

2. Beetles

Many types of beetles feed on vegetable crops and ornamentals, especially when the weather is warm, dry, and wind-free.

And while their colors vary, they all jump, have shiny shells, and leave rounded, irregular holes and pitting where they chew foliage.

One of the most likely species to dine on your pansies is the spotted cucumber beetle, Diabrotica undecimpunctata.

The adults feed on the pansy blossoms and leaves, while the white larvae eat the roots. Young plants are especially vulnerable to root damage.

Cultural Controls

Avoid planting your pansies near vegetable crops.

Deter the pests with reflective silver mulch. For new beds, cover the soil with mulch and cut planting holes six to 12 inches apart to accommodate mature dimensions.

Mechanical Controls

Hand-pick and destroy the beetles as you see them.

Net your pansies to protect them from a neighboring infestation.

Place sticky traps in the vicinity of an outbreak.

Spread diatomaceous earth over the soil to inhibit egg-laying and larval development.

Organic Controls

Apply neem oil on the foliage and the soil around the near the pansies as a deterrent. It is not an effective treatment during infestation.

Chemical Controls

Malathion, is a synthetic organophosphate broad-spectrum insecticide is effective, but it’s likely to destroy beneficials as well as the target beetles, and is toxic to marine life, pets, and people.

Synthetic pyrethroids containing cyfluthrin or permethrin are effective but toxic to people, pets, marine life, and beneficials.

3. Caterpillars

Many butterflies and moths are considered to be beneficial pollinators. Those that lay their eggs on pansies include cutworm moths, fritillary butterflies, leaf tier moths, and looper moths.

Unfortunately, when the larvae, known commonly as caterpillars, hatch, they feed on the pansy foliage, leaving telltale signs such as irregularly chewed holes, folded-over leaves, and stunted growth.

Caterpillars prefer temperate weather. Their colors vary widely, including black, brown, cream, gray, orange, pink, tan, variegated, and yellow.

Many species feed visibly during the day, but others, like cutworms, are active at night.

Cultural Controls

Grow your pansies away from other susceptible ornamentals and vegetables.

Keep the garden free of pest-harboring weeds.

Mechanical Controls

Hand-pick and destroy caterpillars as you see them.

Install feeders and houses that attract caterpillar-eating birds, like warblers, vireos, and grosbeaks.

Bacillus thuringiensis subspecies kurstaki (Bkt) is a microbial insecticide that does no harm to people, pets, marine life, or beneficial insects.

Apply it as soon as the caterpillars hatch for best results. You can read more about Bt in our guide.

Pyrethroids are synthetic versions of naturally occurring insecticidal compounds called pyrethrins. Apply at the egg or larvae stage.

4. Gall Midges

Violet gall midge, Prodiplosis violicola, is one of many species of gnat-like flying midges.

The immature larvae are maggot-like and may be orange, red, white, or yellow. They bore into pansy foliage, creating bump-like galls inside which they live and feed.

In addition to forming galls, violet gall midge feeding causes leaf curling and splitting.

Once a significant threat to the floriculture industry, populations of the species have recently waned. Unless a commercial greenhouse is infested, and you purchase an infected pansy plant, it is unlikely you’ll face this pest.

If your pansies have gall-disfigured foliage, remove and dispose of affected portions. Insecticidal treatments generally prove ineffective.

5. Mealybugs

Mealybugs are a soft-bodied type of scale, an insect we discuss below. They are wingless sapsuckers with a waxy exterior and a preference for warm, dry environments.

You’ll find them hiding on the undersides of the pansy foliage, along leaf veins, where they cluster like aphids and look like little tufts of grayish-white cotton wool.

The excretions of mealybugs will likely lead to an outbreak of sooty mold fungus.

Symptoms of feeding include plant decline and leaf drop. Treatment is challenging due to the waxy protective coating on their bodies and the pests’ habit of hiding.

Cultural Controls

Avoid overfertilizing, especially with nitrogen-rich products that produce the lush, new growth mealybugs prefer.

Maintain moisture to avoid overly dry conditions.

Mechanical Controls

Spray your pansies firmly with the garden hose to dislodge the insects.

Organic Controls

Azadirachtin kills mealybugs in all life stages, and products containing Beauvaria bassiana are also effective.

Horticultural oils, like neem, kill mealybugs and insecticidal soaps may help to reduce populations. 

The mealybug destroyer, Cryptolaemus montrozeuri, is the most effective ladybug species.

Chemical Controls

Isopropyl alcohol may prove an effective treatment for a small-scale infestation in a potted pansy plant. Dip a cotton swab into the rubbing alcohol and gently wipe away the pests.

Systemic pesticides containing dinotefuran, a neonicotinoid or synthetic nicotine-like compound, make foliage toxic to feeding mealybugs.

They may prove more effective than treatments aimed at killing bugs on contact, but neonicotinoids are toxic to bees, beneficials that may feed on mealybugs, marine life, people, and pets.

Our guide to identifying and controlling mealybugs has more information.

6. Scale

Scale are sapsucking insects that prefer hot, dry conditions.

They have a waxy covering or “scale” over their bodies that may be hard, aka armored, or soft, like the mealybug. There are many different types.

Brown soft scale, Coccus hesperidum, is a common pest, particularly in commercial greenhouse settings. Unlike hard scale, soft types excrete honeydew, rendering flora vulnerable to sooty mold.

Scale damage includes foliar yellowing, wilting, and decline. Despite the name “soft,” both have hard, waxy shells that many pesticides can’t penetrate.

The best time to treat is when the “crawlers” or juveniles emerge, but they are too tiny to see with the naked eye.

Cultural Controls

Avoid underwatering and dry conditions.

Mechanical Controls

Use your fingernail or a knife to scrape them off your pansy plants if you only see a few. But beware: the shells of hard scale may lift off, leaving the bodies behind. Scrape again.

The problem with this method is the likelihood of damaging the soft plant tissue of your pansies.

Alternatively, dab them with a cotton swab dipped in isopropyl alcohol.

Larger infestations can be sprayed with a mixture of one cup of isopropyl alcohol, one tablespoon of insecticidal soap, and one quart of water, according to experts at the Missouri Botanical Garden.

Organic Controls

Azadirachtin kills scale but as mentioned before is toxic to people, pets, marine life, and beneficials.

Parasitic wasps and lacewings that prey upon scale are best suited to a greenhouse setting.

Chemical Controls

Neonicotinoid insecticides like acetamiprid, dinotefuran, or thiamethoxam are effective, but best used as a last resort, as they are toxic to people, pets, and marine life, and beneficial insects.

Our scale identification and control guide has further details.

7. Slugs and Snails

Shell-less slugs and their voracious counterparts, spiral-shelled snails, are the most likely pests you’ll encounter because, like pansies, they prefer cool, moist conditions.

These hungry gastropods move by a muscular, foot-like appendage, creating telltale slime trails. They feed through the night on tender pansy foliage, leaving ragged holes.

Gastropods thrive in humidity, laying eggs on moist soil and sheltering out of sight during the day.

In addition to fresh foliage, they feed on decaying flora, like grass clippings and fallen leaves.

Cultural Controls

Avoid overwatering and water your pansies early in the day so the ground is dry by the time the slugs are ready to feed.

If you use mulch, keep it shallow to avoid excessive moisture building up around the base of the plants.

Keep the garden area free of weeds where slugs and snails may spend the day.

Rake grass clippings and fallen leaves that may attract these pests and create desirable damp places beneath them.

Remove debris, like dead plant material, old mulch, and unnecessary articles, like empty flower pots. Gastropods winter over in such places as well as underground.

Space pansy plants well to avoid overcrowding, moisture buildup, and a lack of light penetration.

Mechanical Controls

Hand-pick slugs and snails from your pansies at night.

Place copper strips around plants. Make them wide enough to cause full body contact which causes an electrical shock. Thin strips gastropods can climb over are ineffective.

8. Spider Mites

Spider mites are arachnids, relatives of spiders that favor warm days with low wind. The two-spotted variety, Tetranychus urticae, is one of the most common.

Tell-tale symptoms on your pansies include webbing, leaves with a bronze sheen, and stunted growth. Hot, dry, dusty conditions are conducive to infestation.

Cultural Controls

Avoid underwatering that causes moisture stress, weakening pansy plants and creating dry, dusty conditions.

Clear all garden debris to inhibit wintering over.

Mechanical Controls

Use a firm spray of water to disrupt the pests and dislodge them from the pansy plant. Wetting the foliage also helps to remove dust, another attraction for spider mites.

Organic Controls

Predatory assassin bugs, big-eyed bugs, lacewing larvae, ladybugs, mites, minute pirate bugs, and six-spotted thrips feed on spider mites.

Insecticidal soap and horticultural oil such as neem are also effective.

Pyrethrin-containing products kill spider mites in all life stages, but contain levels of toxicity harmful to beneficials that prey on spider mites, and marine life, pets, and people.

Chemical Controls

While some experts recommend the use of broad-spectrum pesticides containing malathion, bifenthrin, or cyfluthrin, they may not be the best chemical solutions because new spider mite strains are often pesticide-resistant.

Products containing the miticide kelthane are more likely to be effective because they specifically target mites.

These pesticides and miticides are toxic and may harm beneficials that feed on spider mites, marine life, people, and pets.

Our guide to the detection and control of spider mites has more information.

9. Whiteflies

Whiteflies are winged, sapsucking insects more closely related to the aphid and mealybug than the fly.

All life stages live on the undersides of leaves. When disturbed, the winged adults rise from the foliage like a puff of white powder.

Telltale signs of their presence on your pansies include trails of honeydew, sooty mold, stunting, and wilting.

In advanced infestations, the leaves of the pansies may turn yellow and drop. Activity is exceptionally high in hot, dry, dusty environments.

Cultural Controls

Avoid overfertilizing, especially with a nitrogen-rich product that produces lush growth appealing to whiteflies.

Maintain even moisture to avoid creating dry, dusty conditions.

Use reflective copper or silver mulch around your pansies as a deterrent.

Mechanical Controls

Install bird yard features, like baths and houses, to attract smaller avian species, like chickadees and warblers, that feed on whiteflies.

Sticky traps may be all you need to address an early-stage infestation.

Spray a strong stream of water from the garden hose to dislodge pests from the pansy plants and moisten dry, dusty growing areas.

Organic Controls

Azadirachtin kills whiteflies in all stages and Beauvaria bassiana is an effective treatment.

Insecticidal soap applied to the undersides of the leaves kills adults and nymphs, slowing down reproduction.

Neem oil may also reduce populations.

Parasitic big-eyed bugs, lacewings, ladybugs, and wasps prey on whiteflies. 

Chemical Controls

Broad-spectrum synthetic neonicotinoid insecticides containing permethrin and imidacloprid may prove effective but are toxic to beneficials, marine life, people, and pets.

Similarly, synthetic organophosphate malathion treats whitefly infestations but is also toxic.

See our guide to identifying and controlling whiteflies for details.