The main factors that may cause black leaves are as follows: diseases and insect pests; improper fertilization; and improper planting environment, which mainly includes light conditions, ventilation status and watering amount.
If the leaves of the umbrella grow black first and then rot, it may be caused by bacteria. At this time, it is recommended that you spray some fungicides such as carbendazim on the leaves. If you find that there are obvious small insects on their leaves, you can choose to spray "Black Whirlwind". After removing the insects, they will get better after a period of time.
If the fertilizer is not applied properly, the phenomenon of "burning leaves" will appear, which is also the main reason for the discoloration of leaves. If you apply a small amount of fertilizer at a time, but still have black leaves, it is possible that the fertilizer is too close to the root of the umbrella.
Parasol is a plant that likes sunshine. Make sure that the parasol plants are fully illuminated. But the big leaf umbrella is not resistant to high temperature. We should pay attention to the hot weather such as midsummer. Because parasol is generally used as indoor foliage plant cultivation, some friends may ignore the demand for light, if the growth environment is too dark, it will also cause the parasol to drop leaves.
The indoor ventilation condition is as important as the drainage of the soil selected for cultivation. Keep the environment around the umbrella relatively dry. When 80% of the basin soil is dry (at least on the surface), water it again.
