Quick Guide: Pansy Diseases and Insect Pests in South Carolina
Affected Plants: Pansies (Viola × wittrockiana)
Primary Disease Types:
- Anthracnose
- Leaf spots
- Black root rot
- Root and crown rots
- Gray mold (Botrytis blight)
Primary Insect Pests:
- Aphids
- Spider mites
- Slugs
- Snails
Primary Causes:
- Excess moisture
- Poor air circulation
- Overhead irrigation
- Poorly drained soils
- Environmental stress
Most Important Prevention Strategy:
- Grow pansies in well-drained soil
- Avoid overhead watering
- Maintain good air circulation
Chemical Control: Fungicides and insecticides may help suppress severe problems when combined with proper cultural practices
Pansies are among the most popular garden flowers grown today. They are most commonly grown as annuals, producing the best flowers and growth when temperatures are mild in the fall and spring.
Although they are relatively trouble-free, several problems can affect them.
Pansy Diseases: Anthracnose on Pansies
Anthracnose is a fungal disease that causes leaf spotting, blighting, and flower damage on pansies.
Cause
Anthracnose is caused by fungi in the Colletotrichum species.
Symptoms
Symptoms of anthracnose on pansies may include:
- Pale yellow spots with distinct black margins
- Browning and blotching on leaves
- Dry, tan centers within spots
- Concentric ring patterns within lesions
- Spotted or distorted flower petals of infected plants
- Premature decline or death of severely infected plants
Prevention & Treatment
Cultural Controls
- Dig up and destroy severely infected plants.
- Remove infected leaves as soon as symptoms appear.
- Avoid overhead watering.
- Apply a thin layer of mulch around plants to reduce soil splashing onto foliage.
- Improve air circulation around pansies to reduce leaf wetness duration.
Chemical Control
Preventative fungicide applications are typically more effective than curative treatments.
For severe anthracnose infections on pansies, fungicides containing the following active ingredients may help suppress disease development:
- Chlorothalonil
- Mancozeb
Apply fungicides at 7- to 14-day intervals when environmental conditions favor disease development.
Refer to Table 1 for example fungicide products labeled for anthracnose management on ornamental plants.
As with all pesticides, read and follow all label instructions and precautions.
Pansy Diseases: Leaf Spots on Pansies
Several fungal leaf spot diseases can affect pansies, causing spotting, blighting, and premature foliage decline.
Cause
Several fungi may cause leaf spot diseases on pansies, including:
- Alternaria species
- Cercospora species
- Myrothecium species
- Ramularia species
Symptoms
Leaf spot diseases on pansies may cause:
- Transparent tan spots
- Brown lesions
- Black spots on foliage
- Enlarging patches of dead tissue
- Merging lesions that create larger blighted areas
Prevention & Treatment
Cultural Controls
- Remove and destroy infected leaves as soon as symptoms appear.
- Avoid overhead irrigation.
- Reduce leaf wetness when possible.
- Apply mulch to help reduce splashing of fungal spores from the soil onto plants.
- Maintain adequate spacing between pansies to improve air circulation.
Pansy Diseases: Cercospora Leaf Spot on Pansies
Cercospora leaf spot is a common fungal disease of pansies that typically develops during cool fall weather.
Cause
Cercospora leaf spot is caused by fungi in the Cercospora species group.
Symptoms
Symptoms of Cercospora leaf spot on pansies may include:
- Dry, brown blotches on foliage
- Irregular purple lesions
- Increased spotting during cool weather conditions
Prevention & Treatment
Cultural Controls
- Remove infected foliage promptly.
- Avoid overhead watering.
- Improve air circulation around plants.
- Reduce prolonged leaf wetness.
Chemical Control
For severe Cercospora leaf spot infections on pansies, fungicide sprays containing thiophanate-methyl may help suppress disease development.
Apply at 7- to 14-day intervals while environmental conditions favor disease development. Refer to Table 1 for example fungicide products.
As with all pesticides, read and follow all label instructions and precautions.
Pansy Diseases: Black Root Rot on Pansies
Black root rot is a soilborne fungal disease that causes root discoloration, stunting, and decline in pansies.
Cause
Black root rot is caused by the fungal organism, Thielaviopsis basicola, which can affect many ornamental plants.
Symptoms
Symptoms of black root rot on pansies may include:
- Yellowing foliage
- Small, crinkled leaves
- Reduced plant vigor
- Black discoloration moving upward from the root tip
- Stunted growth
- Decline of older plants
Diagnosis may be difficult without professional assistance because root symptoms can resemble other root diseases.
Prevention & Treatment
Black root rot develops more readily in poorly drained or excessively wet soils.
Cultural Controls
- Remove and discard any infected plants promptly.
- Provide good soil drainage
- Avoid excessive irrigation and saturated soil.
- Reduce conditions that promote prolonged soil moisture.
Chemical Control
Fungicides containing thiophanate-methyl may help suppress black root rot, but will not cure infected plants.
Refer to Table 1 for example fungicide products labeled for ornamental disease management.
As with all pesticides, read and follow all label instructions and precautions.
Pansy Diseases: Root and Crown Rot on Pansies
Root and crown rot diseases are common soilborne problems that can cause wilting, yellowing, and plant death in pansies.
Cause
Several soilborne fungi may cause root and crown rot diseases on pansies, including:
- Phytophthora species
- Pythium species
- Rhizoctonia species
- Fusarium species
These fungi infect roots or the crown area near the soil line.
Symptoms
Symptoms of root and crown rot on pansies may include:
- Wilting foliage
- Sudden plant collapse
- Yellowing leaves
- Dark, sunken stem areas near the soil line
- Root decay
- Weak or stunted growth
- Poor plant vigor
Some infected plants may survive but remain stunted and unhealthy.
Prevention & Treatment
Cultural Controls
- Plant pansies in well-drained locations.
- Improve drainage by using raised beds where needed.
- Avoid excessive irrigation
- Allow soil to dry between waterings.
- Avoid overcrowding plants.
- Do not apply excessive mulch around plants.
- Remove and destroy diseased plants promptly.
Chemical Control
Fungicides containing potassium salts of phosphorous acid, applied as a drench, may help suppress root and crown rot diseases on pansies when used preventatively.
Repeat applications are required because fungicides are most effective before severe infection develops. Refer to Table 1 for example fungicide products.
Apply all chemicals according to directions on the label.
Pansy Diseases: Gray Mold (Botrytis Blight) on Pansies
Gray mold, also called Botrytis blight, is a fungal disease that causes soft decay and fuzzy gray growth on pansy flowers and stems.
Gray mold develops most readily during cool, humid, and crowded growing conditions.
Cause
Gray mold is caused by fungi in the Botrytis species.
Symptoms
Symptoms of gray mold on pansies may include:
- Fuzzy, gray fungal growth on flowers and stems
- Soft, slimy, and decayed plant tissue
- Flower blight
- Stem decay
- Visible gray spore clouds when infected flowers are disturbed
Prevention & Treatment
Cultural Controls
- Keep plant surfaces as dry as possible.
- Remove aging and infected flowers promptly.
- Provide good air circulation around plants.
- Avoid overcrowding plants.
- Reduce prolonged moisture on foliage and flowers.
Chemical Control
For severe gray mold infections, fungicides containing the following active ingredients may help suppress disease development:
- Chlorothalonil
- Copper fungicides
- Mancozeb
Repeat applications every 7 to 14 days while environmental conditions favor disease development. Refer to Table 1 for example fungicide products.
As with all pesticides, read and follow all label instructions and precautions.
For additional information on gray mold and its control, please see Gray Mold (Botrytis Blight) (HGIC 2100).
Pansy Insect Pests: Aphids on Pansies
Aphids are common sap-feeding insect pests that damage pansy foliage and produce sticky honeydew on plants.
Identification & Biology
Various aphid species may infest pansies. Aphids are soft-bodied insects that range in color from:
- Black
- Green
- Pink
- Tan
Aphids range in size from 1/16 to ⅜-inch long and feed by piercing plant tissue and sucking plant sap.
Symptoms & Plant Damage
Aphid infestations on pansies may cause:
- Feeding damage on young leaves and stems
- Distorted or weakened new growth
- Sticky honeydew (a sugary waste material) on foliage
- Sooty mold fungus growth on leaves
- Unsightly, dark fungal buildup on plant surfaces
Prevention & Treatment:
Biological Control
Several beneficial insects help naturally suppress aphid populations on pansies, including:
- Ladybird beetles (ladybugs)
- Lacewings
As much as possible, these predators should be allowed to reduce aphid populations. Planting small-flowered nectar plants, such as Queen Anne’s lace (Daucus carota), will help attract these beneficial predators.
Cultural Controls
- Monitor pansies regularly for aphid activity on new growth.
- Preserve beneficial insect populations whenever possible.
- Avoid unnecessary insecticide applications that may kill natural predators.
Chemical Control
Because of their phenomenal reproductive ability, aphids are very difficult to control with insecticides. Leaving a small number of aphids alive can result in the production of a new colony very quickly.
In addition, insecticides kill the beneficial insects that normally keep aphid populations in check.
If natural predators do not reduce aphid populations sufficiently, insecticides containing the following active ingredients may help suppress infestations:
- Acephate
- Bifenthrin
- Cyfluthrin
- Insecticidal soap (naturally occurring)
- Lambda cyhalothrin
- Malathion
- Permethrin
- Zeta cypermethrin
Refer to Table 2 for example insecticide products labeled for aphid management on ornamental plants.
For additional information on less toxic pest management options, see Insecticidal Soaps for Garden Pest Control (HGIC 2771) and Less Toxic Insecticides for Garden and Landscape Pest Control in South Carolina (HGIC 2770).
As with all pesticides, read and follow all label instructions and precautions.
Pansy Insect Pests: Spider Mites on Pansies
Spider mites are tiny sap-feeding pests that damage pansy foliage during hot, dry weather conditions.
Identification & Biology
Two-spotted spider mites (Tetranychus urticae) are occasional pests of pansies.
Spider mites are not insects but are more closely related to spiders. Mites are extremely small and are often difficult to see without magnification.
Spider mite infestations are more common during hot, dry weather.
Symptoms & Plant Damage
Spider mite infestations on pansies may cause:
- Tiny pinprick feeding spots on leaves
- Small tan speckling on foliage
- Leaf discoloration
- Leaf death during severe infestations
- Fine webbing visible on leaves
Early feeding damage may be difficult to detect without close inspection.
Prevention & Treatment
Cultural Controls
- Grow pansies during cooler spring or fall conditions.
- Monitor plants closely during hot, dry weather.
- Reduce plant stress through proper watering practices.
Chemical Control
When spider mite infestations occur, begin applications of insecticidal soap weekly as needed.
Other pesticides labeled for homeowner use against spider mites include products containing:
- Bifenthrin
- Insecticidal soap
- Tau fluvalinate
Refer to Table 2 for example products labeled for spider mite management on ornamental plants.
As with all pesticides, read and follow all label instructions and precautions.
Pansy Insect Pests: Slugs and Snails on Pansies
Slugs and snails are moisture-loving pests that feed on pansy leaves and flowers, especially at night.
Identification & Biology
Snails and slugs are mollusks related to clams and oysters. These pests require consistently moist conditions to survive and are most active at night.
During the day, slugs and snails hide under:
- Flower pots
- Leaf litter
- Mulch
- Moist, shaded areas
Symptoms & Plant Damage
Slug and snail feeding on pansies may cause:
- Large, irregular holes in leaves
- Damage to flowers and blooms
- Ragged feeding injury
- Slimy mucus trail on foliage or nearby surfaces
Prevention & Treatment
Cultural Controls
- Remove mulch and leaf litter near plants to reduce the moist hiding areas.
- Handpick slugs and snails during the evening using a flashlight.
- Water the area before evening inspections to encourage slug and snail activity
- Reduce excessive moisture around plants whenever possible.
Trapping Methods
Slug and snail traps may help reduce pest populations around pansies.
Beer Traps
- Fill shallow containers with beer.
- Place containers in the soil with rims level to the soil surface.
- Slugs and snails are attracted to the yeasty odor and may drown in the liquid.
Board Traps
- Place a board approximately one inch above the soil surface.
- Slugs and snails will hide beneath the board during the day.
- Lift the board regularly to remove and dispose of them.
Physical Barriers
Sprinkle diatomaceous earth around pansies to reduce slug and snail activity.
Diatomaceous earth damages the soft bodies of these pests, leading to dehydration. Reapply after rainfall or irrigation.
Chemical Control
Slug and snail baits containing the following active ingredients may help suppress infestations in landscape beds:
- Iron phosphate
- Metaldehyde (3 percent)
Iron phosphate products are generally less hazardous to pets, birds, and non-target animals than metaldehyde products.
Refer to Table 3 for example slug and snail bait products.
As with all pesticides, read and follow all label instructions and precautions.
Other Problems on Pansies
Environmental and cultural problems can also affect pansy growth, flowering, and overall plant health.
Pansy Problems: Short Blooming Period on Pansies
High temperatures and environmental stress can shorten the flowering period of pansies.
Causes
Pansies grow and flower best when temperatures are below 75°F. Excessive heat may cause flowering to decline and plants to deteriorate prematurely.
Symptoms
Symptoms associated with shortened blooming periods on pansies may include:
- Reduced flowering
- Declining flower quality
- Premature plant decline
- Heat stress symptoms during warm weather
Prevention & Management
- Plant pansies during cool fall or early spring conditions.
- Remove spent flowers regularly (deadheading).
- Cut plants by approximately one-third to stimulate new growth.
- Reduce heat stress whenever possible.
Pansy Problems: Spindly Growth on Pansies
Insufficient light levels may cause weak, elongated growth in pansies.
Causes
Pansies may become spindly when grown in areas with inadequate light.
Symptoms
Symptoms of inadequate light exposure on pansies may include:
- Lanky growth
- Weak stems
- Reduced flowering
- Poor plant form
Prevention & Management
Cultural Controls
- Grow pansies in strong filtered light.
- Provide full sun during cool weather whenever possible.
- Avoid excessively shaded planting locations.
Pansy Problems: Oedema on Pansies
Edema is a physiological disorder caused by excessive internal water pressure within the tissues.
Causes
Oedema develops when plants absorb water faster than can be released through transpiration. The pressure inside the plant builds up, and water ruptures from the stems and leaves.
Cool, cloudy weather combined with wet soil commonly contributes to this disorder.
Symptoms
Symptoms of oedema on pansies may include:
- Wart-like bumps on stems
- Raised growth on flower stalks
- Rough-textured stem surfaces
Prevention & Management
Cultural Controls
- Allow the soil to dry slightly between waterings.
- Plant pansies in well-drained soil.
- Avoid excessive mulch around plants.
- Plant at proper spacing to allow adequate air circulation.
Pansy Problems: Nutrient Deficiencies on Pansies
Nutrient deficiencies in pansies are common in South Carolina landscape beds with improper soil pH.
Pansies grow best at:
- Soil pH of 5.4 to 5.8 in soil-less mixes for containers
- Soil pH of 5.6 to 6.0 for in-ground plantings
Improper soil pH may contribute to micronutrient deficiencies and poor plant growth.
Symptoms
Boron Deficiency Symptoms
- Stunted main shoot growth
- Small, thickened foliage
- Cupped developing leaves
Iron Deficiency Symptoms
- Interveinal chlorosis
- Yellowing between leaf veins
- Symptoms primarily on younger leaves
Magnesium Deficiency Symptoms
- Interveinal chlorosis on expanded younger leaves
- Yellowing between veins on mature foliage
Prevention & Management
Cultural Controls
- Test the landscape soil annually.
- Maintain proper soil pH.
- Avoid excessive application of leaf or mushroom compost.
- Improve soil conditions before planting pansies.
Chemical & Nutritional Amendments
Boron and Iron
To help correct boron and iron deficiencies, apply a micronutrient product containing:
- Boron
- Iron
Micronutrient products may also help lower excessively high soil pH.
Southern Ag Essential Minor Elements is an example of a micronutrient product that contains iron, boron and several other micronutrients.
Apply 1 cup per 10 square feet of beds. Always apply this product when the foliage is dry and water the granules into the soil.
A small amount of leaf compost mixed into the soil (10% by volume) will provide the boron that plants require.
Magnesium
A magnesium deficiency may occur if the soil pH drops below 5.4 or if calcium levels are high due to excessive application of leaf or mushroom compost.
For magnesium deficiency, apply Epsom salts (magnesium sulfate) at a rate of:
- 1 tablespoon per gallon of water
Always follow all product label directions and precautions.
Table 1. Fungicides for Pansy Disease Management
The following fungicides are labeled for suppression or management of common pansy diseases in home landscapes.
Active Ingredient |
Example Product Names |
| Chlorothalonil | Bonide Fung-onil Multi-purpose Fungicide Concentrate Bonide Fung-onil Multi-purpose Fungicide Ready to Use Ferti-lome Broad Spectrum Landscape & Garden Fungicide GardenTech Daconil Fungicide Concentrate GardenTech Daconil Fungicide Ready-to-Use Hi-Yield Vegetable, Flower, Fruit And Ornamental Fungicide Ortho MAX Garden Disease Control Concentrate Southern Ag Liquid Ornamental and Vegetable Flowable Fungicide Tiger Brand Daconil |
| Copper Fungicides | Bonide Captain Jack’s Liquid Copper Fungicide Bonide Copper Fungicide Spray or Dust Ready to Use Camelot O Fungicide/Bactericide Monterey Copper Fungicide Garden Spray Liqui-Cop Natural Guard by ferti-lome Copper Soap Fungicide Concentrate Natural Guard by ferti-lome Copper Soap Fungicide Ready to Use Southern Ag Liquid Copper Fungicide |
| Mancozeb | Bonide Mancozeb Flowable with Zinc Concentrate Southern Ag Dithane M-45 |
| Potassium Salts of Phosphorous Acid | Monterey Garden Phos |
| Thiophanate Methyl | Southern Ag Thiomyl Systemic Fungicide |
Table 2. Insecticides and Miticides for Pansy Pest Management
The following insecticides and miticides are labeled for the management of common pansy insect pests and spider mites.
Active Ingredient |
Example Product Names |
| Acephate | BioAdvanced Science-Based Solutions 2-in-1 Systemic Rose & Flower Care Granules with 6-9-6 Fertilizer Bonide Systemic Insect Control II |
| Bifenthrin | Hi-Yield Bug Blaster Bifenthrin 2.4 Ready to Spray Hi-Yield Bug Blaster II Bifenthrin 2.4 Ready to Spray Monterey Mite & Insect Control Monterey Mosquito Control Martin’s FLEE Ready to Use Yard Spray Ortho Outdoor Insect Killer Concentrate Ortho Bug B Gon Insect Killer for Lawns & Gardens1 Ortho BugClear Insect Killer for Lawns & Landscapes Bifen I/T Talstar P Professional Insecticide Up-Star Gold Insecticide Hi-Yield Vegetable & Ornamental Insect Control Granules Bonide Eight Insect Control Flower & Vegetable Above & Below Soil Insect Granules |
| Cyfluthrin | BioAdvanced Science-Based Solutions 24 Hour Lawn Insect Killer Ready-to-Spray BioAdvanced Science-Based Solutions Complete Brand Insect Killer for Soil & Turf Ready-to-Spray I BioAdvanced Science-Based Solutions Insect Killer for Lawns Ready-to-Spray BioAdvanced Science-Based Solutions Rose & Flower Insect Killer Ready-to-Use |
| Insecticidal Soap3 | Bonide Insecticidal Soap Multi-purpose Insect Control Ready to Use Garden Safe Brand Insecticidal Soap Insect Killer Miracle-Gro Nature’s Care Insecticidal Soap Natria Insecticidal Soap Ready-to-Use Natural Guard by ferti-lome Insecticidal Soap Concentrate Safer Brand Insect Killing Soap Concentrate II Whitney Farms Insecticidal Soap 1 |
| Malathion | Bonide Malathion 50% Insect Control Gordon’s Malathion 50% Spray Hi-Yield 55% Malathion Insect Spray Martin’s Malathion 57% Ortho Max Malathion Insect Spray Concentrate Southern Ag Malathion 50% EC Spectracide Malathion Insect Spray Concentrate Tiger Brand 50% Malathion |
| Lambda or Gamma Cyhalothrin | Bonide Eight Insect Control Garden & Home II Ready to Use Cutter Backyard Bug Control Spray Concentrate Cyzmic CS Controlled Release Insecticide Martin’s Cyonara Lawn & Garden Insect Control Martin’s Cyonara Lawn & Garden Insect Control Ready-to-Spray Spectracide Triazicide Insect Killer for Lawns & Landscapes |
| Permethrin | Bonide Eight Insect Control Vegetable, Fruit, & Flower Concentrate Bonide Eight Yard & Garden Ready to Spray Hi-Yield 38 Plus Turf, Termite & Ornamental Insect Control Hi-Yield Lawn Garden Pet & Farm Insect Control Southern Ag Permetrol Lawn & Garden Insecticide Tiger Brand Super 10 Brand |
| Tau-Fluvalinate | BioAdvanced Science-Based Solutions All-in-One Rose and Flower Spray BioAdvanced Science-Based Solutions 3-in-1 Insect, Disease & Mite Control BioAdvanced Science-Based Solutions 3-in-1 Insect, Disease & Mite Control Ready-To-Use BioAdvanced Science-Based Solutions 3-in-1 Insect, Disease & Mite Control I |
| Zeta Cypermethrin | Gordon’s Bug-No-More Lawn & Garden Insect Control Gordon’s Bug-No-More Large Property Insect Control GardenTech Sevin Insect Killer Concentrate GardenTech Sevin Insect Killer Ready-to-Spray |
| 1 RTS = Ready to Spray (a hose-end sprayer) 2 RTU = Ready to Use (a pre-mixed spray bottle) 3 Do not apply insecticidal soaps when the temperature is above 90 °F or to drought-stressed plants. Spray late in the day for best control. With all pesticides, read and follow all label instructions and precautions. |
|
Table 3. Slug and Snail Baits for Pansies
The following bait products may help manage slugs and snails around pansies in landscape beds and containers.
Active Ingredient |
Example Product Names |
| Iron Phosphate Baits | Bonide Bug & Slug Killer (contains spinosad) Bonide Slug Magic – Makes Slugs Disappear Garden Safe Brand Slug & Snail Bait Monterey Sluggo – Kills Slugs & Snails Monterey Sluggo Plus (contains spinosad) Natural Guard Brand by ferti-lome Bug, Slug & Snail Bait (contains spinosad) Natural Guard Brand by ferti-lome Slug & Snail Bait Whitney Farms Slug & Snail Killer 1 |
RTS = Ready to Spray (a hose-end sprayer)
RTU = Ready to Use (a pre-mixed spray bottle)
Pesticide Disclaimer
Pesticides are updated annually. Always read and follow all label directions, precautions, and restrictions.
Mention of specific products does not imply endorsement by Clemson University, nor does omission imply discrimination against similar products.
Protecting Pollinators During Pesticide Applications
Pollinating insects, including honey bees and bumblebees, may be harmed by unnecessary or improperly timed pesticide applications.
Reduce Pollinator Exposure
- Avoid spray pesticide applications whenever possible.
- Avoid unnecessary use of systemic insecticides.
- Apply pesticides only when pest populations justify treatment.
- Use cultural and non-chemical controls first whenever possible.
- Spray pesticides late in the evening to reduce exposure to pollinators.
- Avoid spraying plants during active bloom periods when pollinators are present.
Lower-Risk Pest Management Options
Several lower-risk pesticide products may help reduce impacts on pollinating insects when used properly.
Examples may include products containing:
- Insecticidal soap
- Horticultural oil
- Neem oil extract
- Spinosad
- Bacillus thuringiensis (B.t.)
- Botanical oils
Neem oil extract or botanical oil sprays may also reduce plant damage by repelling many insect pests.
If soil-applied insecticides are used, apply them immediately after flowering to reduce pollinator exposure.
For more information, contact the Clemson Home & Garden Information Center.
Pesticides are updated annually. The last updates were made on 05/26 by N. Jordan Franklin.
Originally published 05/99
