Gardenias are my favorite shrub plants, they are very fragrant. Which makes them an incredible option to have as indoor flowers, I always have them near a window. Personally, their scent is sweeter than the most fragrant roses, so you can imagine. Furthermore, gardenias also have glossy, dark evergreen leaves which make a beautiful backdrop to their flowers. However, they are also susceptible to diseases. So imagine my frustration when I see the leaves with a sooty film. The panic was there too so I start to immediately look for solutions so I don’t lose my beautiful gardenia plants! Hence, if you face the same problem, keep reading and see how to get rid of the black soot on gardenia leaves.
What is that black sooty mold?
Well, the sooty substance is actually sooty mold. Yes, that’s right, the fungus is invading your gardenia leaves and it is spreading due to insects. Hence, as you can probably assume, the problems only get worse. Thus, this means you need to act immediately so the leaves remain healthy and your flower blooming. Fortunately enough, the black soot only remains on the leaf’s surface, so there is no damage to the structure of the plant. However, the fungus will interfere with the plant’s process of blooming. Thus, a severe infestation will definitely make your plant weaker considerably.
Let’s see some effective methods you can use to get rid of this black soot on gardenia leaves:
Prevention & Insect Control Methods
Yes, this black soot only exists because there are insects, mostly whiteflies, aphids, scales, and mealybugs. These little annoying pests feed on the sap of plants. While feeding on a plants sap, the insects will excrete a substance such as honeydew. A heavy insect infestation will coat all of a plant’s leaves with honeydew.
Thus, the fungi start feeding on the honeydew and it quickly spreads to surrounding leaves, stems and plants. Hence, the best solution for this issue is prevention and insect control.
To rid your plants of black soot, you need to control the insects which are producing the sugary honeydew that the fungus feeds on. One way would be to use insecticides which are very useful for controlling insect populations.
Thus, for whitefly and aphid control, you should try neem oil or paraffinic oil.
Furthermore, for scales and mealybugs, you should try fish oil or horticultural oil.
You could also make your own DIY solution of soapy water and spray your plants every few days. Hence, use two big squirts of dish soap to one gallon of water in a one-gallon sprayer. It is important to douse every inch of the plant, paying special attention to the underside of leaves.
So, basically, if you cut off the food source, you will eliminate the bugs and the fungus will slowly starve to death. As to the residual mold, spraying your plants with the soapy water washes most of the mold off. If there is still quite a bit of sooty mold left, you could use a garden hose with an adjustable spray nozzle to finish the job.