In order to pinpoint the likely cause, it helps to thoroughly examine the plant and take note of any pests or environmental factors that may be affecting its overall health. common reasons for a plant dropping leaves. leaves drop for many reasons, including environmental stress, pests and disease.. Some leaf drop on houseplants is normal. older plants should be expected to drop a leaf or two occasionally. this is particularly the case with plants that grow upright like umbrella plant or cane plant, losing lower leaves as newer ones form on the top.. The plant is shedding lower leaves to allow new growth. insects: mealy bug and scale can be a slight problem. here you will find instructions and advice for pruning and repotting a dracaena marginata
