Why is there always oil on kumquat leaves raised in pots at home?

It is mainly caused by the harm of scale insects. Oily things are the secretion of scale insects. The scale insect clings to the branches and leaves, motionless. They feed on plant juice, which is fast in reproduction and harmful, and needs to be prevented in time. General drugs are not effective, so special biocides are needed.

Such as: pesticide, chlorpyrifos, machinery, stinging will kill people, etc.

In addition, you can also use an old toothbrush, which can also play a certain role. If you leave the plant, the worm will die, but there are many leaves, so it is more troublesome to brush! !