I live in Central Florida (Brevard County), and I have two tropical hibiscus trees that I purchased from Lowe's about a year and a half ago. The tags said they are "Celia" hibiscus. They have the large, ruffled, layered red flowers. I have had them in two large concrete planters ever since. They did well for a long time. Then I went through an aphid infestation, which I struggled with for several months and finally got rid of. They did well for a few months after that and now I am noticing ants crawling around in trails along the trunk and branches of the plant. Also, the leaves towards the center of them are turning a mottled yellow green color and eventually dropping off. I see no signs of other pests (aphids, etc.). I treated them a few days ago with an organic pesticide called "Organocide," which I purchased from Walmart after having no luck with soapy water. This pesticide is supposed to treat almost any pest or disease in the garden. The problem still seems to persist. However, we have received a lot of rain over the past few days. Do I need to retreat? Here is the care routine that I perform on the plants regularly: I water them every 1-2 days when we do not have rain and I don't allow them to dry out. I fertilize with a water soluable fertilizer packet 15-30-15 for blooming plants (Cottage Farms Bloom Booster Packets, which I use on all my other blooming container plants with great results). The directions say to dilute one packet in one gallon of water and I usually put about one gallon on each tree. I am wondering if maybe it could be an issue related to fertilizing. Do I need to be using a more balanced fertilizer? The plants are loaded with blooms but why the dropping yellow leaves and ants? I would really appreciate any help anyone could provide, as I just don't seem to know what to do. I love these trees and would be so dissapointed if they die, and I am tired of them looking so bad. The plants still have green leaves but there is a lot of yellowing going on. I have also been clipping the yellow leaves off and disposing of them but the yellow leaves return within a few days.
Tropical Hibiscus Issues
Certified GKH Gardening Expert
The ants themselves are not a problem, but they are likely on the plant because of aphids, which secrete sweet honeydew. This is what attracts the ants, so really getting rid of the aphids will in turn get rid of the ants as well. Neem oil is the most effective pesticide and is safe to use. Here is more information: https://www.gardeningknowhow.com/problems/pests/neem-oil-uses.htm For additional suggestions, these articles should help: https://www.gardeningknowhow.com/plant-problems/pests/keeping-ants-of-flowering-vines-vegetables-and-flowers.htm, https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/answers-to-what-causes-hibiscus-leaves-turning-yellow.htm