Aphids on hibiscus are a frequent problem in the spring and not just hibiscus but on many kinds of plants.
Aphids are very tiny, pear-shaped insects measuring no more than 6/100 of an inch long.
They vary in color from pale yellow-green to a deep greenish black depending upon the species of aphids.
The Melon aphid (Aphis gossypii) which is also known as the black aphid is especially attracted to the juicy stems and leaves of the Hibiscus plant.
They tend to feed on succulent new growth and hibiscus flower buds.
What Damage Do Aphids On A Hibiscus Cause?
Large aphid populations can cause extensive damage:
- Leaf distortion
- Pale yellow or cream-colored spots
- Leaf Curling
- Entire leaves may turn brown and fall
- They leave a black sooty mold on the foliage
Very large, untreated aphid infestations can cause plant collapse. In addition to direct damage, aphids carry plant viruses that affect Hibiscus plants.
Pest Management: How To Control Aphids on Hibiscus?
Aphids tend to gather in clusters on the undersides of leaves of the plants and on hibiscus buds.
Using their needle-like mouthparts they suck the sap of plants.
Even though they are very tiny, they are usually easy to see with the naked eye.
If you don’t immediately see aphids, you may see ants. Ants like to feast on the sweet, sticky substance aphids excrete called honeydew.
When you notice aphids, control them with one or more of these tips.
Encourage Beneficial Insects
One of the best methods of aphid pest control on Hibiscus is to avoid having them at all. You can do this by encouraging natural enemies (predators) in your garden.
Ladybugs (lady beetles) are famous for feasting on aphids, and they make a cheerful and pleasant addition to any garden. Other beneficial bugs making short work of aphids include:
Wash Aphids Away
If aphids manage to get a toehold in your garden, try washing them away. Use a strong stream of water from your garden hose every other day.
Wash your infested hibiscus plants thoroughly spraying the entire plant and knock the aphids to the ground.
For the most part, a strong stream of water will drown aphids. Even those managing to survive will not be able to make their way back onto your plants again.
Once you’ve got the problem under control, make a habit of washing your plants down once every couple of weeks to discourage aphid infestation.
Use Natural Oils and Soaps To Get Rid Of Aphids
Aphids are quite delicate and easy to kill off with horticultural oil, Neem oil or insecticidal soap solution.
The addition of essential oils such as oil of rosemary or oil of lavender, garlic or hot pepper may also help in killing aphids.
These natural products are inexpensive and do little harm to natural predator populations. If you do use a natural pesticide, be sure to spray every part of the plant.
Get the undersides of the leaves and any crooks and crannies to be sure of contacting every single aphid.
NOTE: It is best to spray in the early morning when the outside temperatures are below 80° degrees Fahrenheit.
Pyrethrum is a botanical poison is a step up from natural soaps and oils. It will kill aphids and can harm beneficial insects, so use it with care and only when necessary.
To use it, mix a tablespoonful of concentrated pyrethrum into a pint of rubbing alcohol and apply as a spray directly on the congregated aphids.
Use Diatomaceous Earth (DE)
Dust DE on the leaves and stems of Hibiscus suffering infestations. DE can be harmful to all sorts of insects, so apply it judiciously and only as needed.
Don‘t Use Sticky Traps
Although you may see some recommendations for sticky traps designed explicitly for aphids, these are not a good idea. The traps do not discriminate.
They may be designed explicitly for aphids, but their bright yellow color and deadly sticky substance can do a great deal of damage to beneficial insects as well as aphids.
Use imidacloprid As A Last Resort
Imidacloprid is a systemic pesticide that can be used as a soil drench. The chemical is taken up into the tissues of the plant through the roots.
It poisons aphids as they consume the sap of your plant. Unfortunately, this pesticide will also kill bees visiting your flowers. Never use imidacloprid on plants in bloom.
This pesticide should be used only as a last resort in the event of very severe infestations in gardens suffering from a lack of natural predators and pollinators.
Aphids Infestation On Hibiscus
How To Prevent A Return Of Aphids
In addition to establishing an environment that encourages beneficial insects, you can also discourage aphid reproduction by keeping your yard and garden clean.
At the end of the growing season, clean up the flower beds and hedges thoroughly.
Clean up stray twigs, and leaf litter then dispose of the debris by burning. This will eliminate aphid eggs waiting to hatch in the springtime.