Carnations are herbaceous perennials from the Dianthus genus known for their gorgeous flowers and sweet, spicy fragrance. However, all types of carnations are vulnerable to various pests and diseases. In this article, we’ll look at ten common carnation pests and diseases and how to deal with them.
10 Common Carnation Pests and Diseases:
Aphids are small black or green sap-sucking insects that can feed on carnations. Aphids gather underneath leaves or along stems. Symptoms of aphid infestations include black mold and distorted or stunted growth.
Spray plants with a hose to dislodge large numbers of aphids. You can also eliminate aphids using insecticidal soap or horticultural oils like neem oil. Alternatively, you can encourage aphid predators like hoverflies and ladybirds.
2) Bacterial Wilt
Bacterial wilt is a fungal disease that can infect carnations. Symptoms of bacterial wilt include wilting leaves and brown, mushy stems. Bacterial wilt also causes black spots with yellow outer rings to appear on infected plants.
Growing carnations properly helps prevent bacterial wilt. Plant carnations in loose, well-draining soils and space them 6 to 12 inches apart to improve air circulation. Some carnations are also resistant to bacterial wilt.
3) Botrytis Blight
Also called gray mold, botrytis blight is a common fungal disease. Infected carnations display deposits of gray mold. Other symptoms of botrytis blight include brown spots on the flowers or blackened flower buds.
Promote good air circulation by spacing carnations 6 to 12 inches apart. Avoid overwatering carnations as botrytis blight thrives in warm, humid environments. Cut off infected parts of any carnations showing symptoms.
Caterpillars are the larval stage of moths and butterflies, and various species can target carnations. These common carnation pests eat through leaves before turning into adult butterflies or moths. Visible caterpillars and bite marks on the leaves are the main symptoms.
Pick off any caterpillars that you find on your carnations. Healthy carnations should survive small caterpillar infestations, although larger infestations can kill carnations.
5) Fusarium Wilt
Fusarium wilt is another fungal disease that can affect carnations. Infected plants start wilting on one side. The leaves also become discolored and turn yellow. The stems might also split and start showing brown lesions. Fusarium wilt is more common in warm temperatures.
Unfortunately, there is no treatment for fusarium wilt. Destroy infected carnations and replace them with cultivars that are resistant to fusarium wilt.
6) Leaf Spot Diseases
Leaf spot diseases infect carnations and cause brown spots with purple rings to appear on the leaves. These common carnation fungal diseases are more prevalent in warm, humid conditions. Leaf spot diseases can also cause carnations to drop their leaves.
Promote good air circulation by growing your carnations in loose, well-draining chalky, sandy, or loamy soils. If your carnations do become infected, eliminate leaf spot diseases using organic fungicides.
7) Powdery Mildew
Powdery mildew is a fungal disease that causes powdery white patches to appear on carnations. Other symptoms of powdery mildew include curled or discolored leaves. Powdery mildew thrives in warm, humid conditions.
Remove any leaves that show signs of powdery mildew. Grow carnations in loose, well-draining soils with approximately 6 to 12 inches of space away from other plants. This promotes good air circulation.
8) Root Rot
Root rot is a common carnation fungal disease that is usually caused by overwatering. Root rot causes drooping, yellowing leaves, and misshapen or stunted growth. Infected carnations will have brown, mushy, or smelly roots.
Trim off infected roots and replant your carnations. Plant them in loose, well-draining soils and water them once a week. Give carnations at least six inches of space away from other plants to promote air circulation.
9) Scale Insects
Scale insects are sap-sucking insects with waxy armored shells. Scale insects can be seen feeding on leaves. Symptoms of scale insects include black mold, which is caused by deposits of honeydew, and white eggs underneath leaves.
Eliminate these common carnation pests and diseases by using insecticidal soap or horticultural oils. If your carnations are suffering from a large infestation, use organic pesticides. Alternatively, use biological controls such as nematodes or ladybird larvae.
10) Spider Mites
Spider mites are tiny insects that feed on chlorophyll. Symptoms of spider mite infestations include white webs on the leaves, stunted or distorted growth, and brown or yellow leaf spots. Spider mites are more common in hot, dry conditions.
Get rid of spider mites using insecticidal soap or horticultural oils like neem oil. Carnations can survive small spider mite infestations. However, eliminate large infestations using organic pesticides.
Carnation Pests and Diseases FAQs:
What are some common garden pests that affect carnations?
Some common garden pests that can damage carnation plants include scale insects, mites, aphids, and mealybugs.
How can I identify a carnation pest problem?
Look for signs of damage, such as distorted or curling carnation leaves or flowers, yellowing leaves, or a sticky residue on the plant. You may also be able to see the pests themselves on the plant through careful observation (though many can be tiny!).
What can I do to prevent pests from damaging my carnations?
What are some common diseases that affect carnations?
Carnations can be susceptible to fungal diseases such as leaf spot, leaf gall, yellow mottle virus, and root rot.
How can I identify a carnation disease problem?
Look for signs of discoloration or spots on the leaves, wilting or drooping of the plant, or fungal growth on the plant.
What can I do to prevent diseases from damaging my carnations?
Are there any organic or natural methods for controlling pests and diseases on carnations?
Yes, there are several natural methods for controlling pests and diseases on carnations, including introducing beneficial insects such as ladybugs or lacewings, using neem oil or garlic spray, and adding compost or other organic matter to the soil to improve plant health.
Carnation Pests and Diseases: Wrapping Up
Carnations are vulnerable to pests like aphids and scale insects and diseases like gray mold and powdery mildew. Eliminate pests using horticultural oils and insecticidal soap. Provide good growing conditions and give carnations plenty of space to promote good air circulation and prevent diseases. Treat diseases using organic fungicides.
For more, see our in-depth guide to carnation growing zones and native ranges, the uses and benefits of carnation flowers, carnation plant toxicity to pets, the fastest growing carnation flowers, tips on managing non-flowering carnations, beautiful flowers that pair well with carnations, and how to propagate and transplant carnation flowers in your garden.
Edd is a budding content writer and gardener living in the United Kingdom. He has a bachelor's degree in Creative and Professional Writing and has written for several gardening publications online. He is passionate about nature and sustainability with a focus on gardening and wildlife.