9 Common Hibiscus Pests and How to Deal With Them

Whilst hibiscus plants take pride of place in my summer display, I find they can be pretty attractive to a variety of pests. In my experience, Aphids are one of the most common invaders; they’re tiny, sap-sucking insects that can cause the leaves to curl and weaken the plant. Spider mites, which are even smaller and can be hard to spot, also pose a threat, especially in dry, hot conditions, leading to speckled leaves and overall plant stress. In addition, there’s the pesky Whitefly and determined Thrip to deal with. In this guide, I’ll go through 9 of the most common hibiscus pests and share what I do to tackle the problem in my garden.

1) Aphids

Aphids are common sap-sucking garden pests that target hibiscus plants. These tiny black or green insects excrete honeydew, a sticky substance that encourages the growth of sooty black mold. Misshapen or stunted growth is another symptom of an aphid infestation.

Aphids congregate underneath leaves and along stems. In my experience, the best pest control method is to use a hose to remove large numbers of aphids quickly. Alternatively, I’ll use biological controls, insecticidal soap, or horticultural oils like neem oil.

2) Botrytis Blight

Botrytis blight is a common fungal disease often called gray mold after the growths that appear on infected plants. Large spots that turn from brown to black may also appear on flower buds.

Botrytis blight loves humid conditions, so provide good air circulation by leaving enough space between your hibiscus and other plants. When present, I remove any infected parts of my hibiscus and burn them to stop the disease from spreading.

3) Japanese Beetles

Japanese beetles are annoying pests that eat hibiscus leaves and flowers. Adults have brown bodies with metallic green heads and lay their eggs in the soil. The larvae start to eat nearby roots once they hatch.

Whilst not the friendliest of options, I recommend picking off adult Japanese beetles and submerging them in a bucket of water. Another option is to use Japanese beetle traps to lure these pests away from your hibiscus. You can also eliminate them using horticultural oils or insecticidal soap.

4) Leaf Spot Diseases

Leaf spot diseases are common fungal infections that can impact hibiscus plants and thrive in warm, humid conditions. Yellow or black spots appear on infected leaves. The grayish-white fungus may develop on the undersides of infected leaves.

Leaf spot diseases interrupt photosynthesis, causing your hibiscus to produce weak or stunted growth. In my experience, the best method to eliminate leaf spot diseases is using organic fungicides and giving my hibiscus plants plenty of space to promote good air circulation.

5) Mealybugs

Mealybugs are slow-moving, sap-sucking insects with oval-shaped bodies covered in white wax that can impact hibiscus plants. Symptoms of a mealybug infestation include clumps of fluffy white wax and weak or stunted growth. Mealybugs also produce honeydew, which can lead to the appearance of sooty black mold.

Mealybugs cause hibiscus plants to produce weak or stunted growth. I always treat them using insecticidal soap or horticultural oils. You can also use biological control methods like mealybug destroyers.

6) Powdery Mildew

Powdery mildew is a common fungal disease that can infect hibiscus plants. Symptoms of powdery mildew include powdery white growths on hibiscus foliage and curled or discolored leaves. Powdery mildew can also cause stunted growth.

Powdery mildew thrives in humid conditions, so avoid overwatering your hibiscus. In my experience, promoting good air circulation by leaving plenty of space around your plants is often the most effective method. I also remove infected leaves and any leaf debris around my hibiscus.

7) Scale Insects

Scale insects are another type of sap-sucking pest that can infest hibiscus plants. Scale insects are small bugs with waxy armored shells that can be spotted crawling over leaves. Symptoms include deposits of honeydew, sooty black mold, and white eggs on the undersides of leaves.

I find the best way to get rid of scale insects is to use insecticidal soap or horticultural oils. You can also use biological controls or organic pesticides to eliminate large-scale insect infestations.

8) Whiteflies

Whiteflies are small white-flying insects closely related to aphids. Whiteflies feed on sap and excrete deposits of honeydew that can lead to the growth of black sooty mold. Other symptoms include yellowing or wilting leaves on hibiscus plants.

In my experience, the best methods to eliminate whiteflies are biological controls, insecticidal soap, and horticultural oils. I also use a hose to dislodge eggs and adults from my hibiscus. Whiteflies thrive in warm weather, so be vigilant during the summer.

9) Wilt Disease

Wilt disease is a fungal infection caused by fungi entering your hibiscus through the roots. These fungi impair your hibiscus’s ability to circulate water properly. Wilt disease affects the entire plant, causing wilting, dying leaves that turn dark green or black rather than yellow.

I treat this issue by misting the leaves of my hibiscus daily until the leaves look healthy and new growth appears. In some cases, the disease can’t be stopped, which unfortunately means you’ll have to dispose of your hibiscus.

Wrapping Up

Hibiscus flowers can be vulnerable to pests like aphids, mealybugs, or diseases such as gray mold or wilt disease. Treat diseases with organic fungicides and eliminate pests using horticultural oils and insecticidal soap. Provide ideal growing conditions to reduce the risk of pests and diseases in the future.

Further reading: See our in-depth Hibiscus handbook.