My Hibiscus Has Black Mites

Spider Mites

• If mites are attacking your hibiscus, they are most likely spider mites, which thrive in hot, dry temperatures. Spider mites are not easily visible to the naked eye. One of the first signs of these insects is yellow foliage, which may start off as a few mottled yellow and green leaves and quickly spread until nearly all of the leaves have yellowed. If the infestation continues, you will begin to notice webbing at the ends of the hibiscus branches, and a magnifying glass can help you see both the webs and the mites. If you do not get rid of them, mites can cause all of the hibiscus leaves to fall off.

Black Aphids

• Those tiny black spots on your hibiscus may not be mites but aphids. While spider mites can be difficult to see without a magnifying glass, aphids are visible to the naked eye. They do not build webs but excrete a sticky substance that lands on the leaves and causes a black mold to begin forming. This mold can cover the plant and, if left untreated, will prevent it from getting the necessary sunlight. Aphids reproduce rapidly and can infest your entire plant in a matter of a week or two.

Getting Rid of Insects

• You can kill both spider mites and aphids in a variety of ways. A pesticide with the chemical abamectin is good for getting rid of a mite infestation while the chemical imidacloprid works well on aphids. You can also use a horticultural oil to spray the plant down for either infestation, though you will need to repeat this process every few days to keep the insects from returning. Your local garden center can advise you further on which product to use and how to use it.

Additional Tips

• You may also be able to get rid of spider mites and their eggs by drowning them. Use a hard stream of water from your garden hose and wash the plant from top to bottom, making sure to get every leaf, branch and twig. Aphids may respond to this as well but check with your garden center to be sure. When treating pests on your hibiscus, choose a method you are comfortable with and whose instructions you can carry out explicitly -- this is your best defense against a returning infestation.