Hey Everyone!
Summer is well on the way here in the South, and your crape myrtles should be hitting their stride with vibrant new growth and those beautiful blooms on the way. But this time of year, many of us notice something else showing up: aphids. 🪲
These small insects are one of the most common pests for crape myrtles, especially here in North Florida. Don’t panic — they rarely kill a healthy, established tree — but they can make your plants look unsightly and stressed if left unchecked.
Meet the Crape Myrtle Aphid
The specific aphid that targets crape myrtles is Tinocallis kahawaluokalani (also known as the crapemyrtle aphid). These tiny insects are usually pale yellow to light green and about the size of a pinhead. You’ll most often find them clustered on the undersides of leaves and along tender new stems.
They appear in spring as eggs laid the previous fall hatch with the new leaf growth. Throughout the summer, they reproduce rapidly — females can produce live young every 10–14 days without mating, leading to quick population explosions when conditions are right. By fall, they shift to producing males and females that lay overwintering eggs.
Why They Show Up Now
Aphids love tender new green growth. That lush, succulent foliage your crape myrtles push out in late spring and early summer is basically an all-you-can-eat buffet for them. They use piercing-sucking mouthparts to drink the plant’s sap, which is rich in sugars.
First Signs of an Infestation
The earliest clue is often shiny leaves. This comes from honeydew — a sticky, sugary substance that’s essentially aphid waste (yes, aphid poop). You might also see leaves beginning to curl, distort, or yellow. If things progress, you’ll spot the aphids themselves and, soon after, black sooty mold.
What an Infestation Can Do
Heavy aphid feeding can:
- Cause leaf curling and distortion
- Reduce the tree’s vigor and bloom production
- Lead to premature leaf drop in severe cases
The real eyesore is the honeydew, which coats leaves, branches, and anything underneath the tree. This sticky layer allows sooty mold (a fungus in the genus Capnodium) to grow. Important note: sooty mold doesn’t feed on the plant itself — it feeds on the honeydew. It blocks sunlight and photosynthesis, making leaves look black and dirty, but controlling the aphids is what truly stops the mold.
Prevention and Control Strategies
Prevention is your best friend. Healthy trees with good air circulation, proper watering, and balanced (not excessive nitrogen) fertilization are less attractive to aphids.
Here’s what works well in our experience:
- Dormant Oil: Apply horticultural dormant oil in late fall (as leaves drop) and again in early spring (as buds swell). This smothers overwintering eggs and can significantly slow spring populations.
- Systemic Insecticide: A soil drench with imidacloprid (a systemic) in spring, after a few inches of new growth, provides good season-long protection. It’s absorbed by the roots and moves through the plant, protecting new growth as it emerges. Many gardeners reapply mid-summer if needed.
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Organic and Gentle Options:
- Strong spray of water (early morning) to knock them off
- Insecticidal soap or neem oil sprays (apply in evening to protect pollinators)
- Homemade mild dish soap solution
- Encouraging natural predators like ladybugs, lacewings, and hoverflies
For heavier infestations, targeted foliar sprays may be needed, but always follow label instructions and apply in the evening.
A Note on Sooty Mold
Once sooty mold appears, it won’t disappear overnight even after the aphids are gone. It gradually weathers away as new leaves emerge and old ones drop. The key is preventing the honeydew in the first place by staying on top of the aphids.
Aphids are just part of gardening with crape myrtles in the South. With early attention and the right steps, your trees will bounce back beautifully and still put on a spectacular show this summer.
Have you dealt with aphids this season? What methods have worked best in your garden? Share in the comments — I always love hearing real-life tips from fellow gardeners.
Until next month, keep those hands dirty and your crape myrtles thriving!
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