Leaf drop is a frustrating problem because it's so hard to diagnose and correct ... and it may not even be a problem at all! Leaf drop is a normal condition of growth for many plants, whose lower leaves gradually die and fall off. If, however, you suddenly lose a lot of leaves at once, or you start losing healthy green leaves, then you might have one of the following problems:
- Shock. This is the most common cause of leaf drop, but it can be the hardest to correct. In my experience, shock is most often caused by a sudden change in conditions. This can mean fluctuations in temperature, light, or watering habits. Newly acquired plants, for instance, often go into shock as they transition from the perfect conditions of a greenhouse to less-than-ideal home conditions. The same is true for newly repotted or divided plants. Sadly, there's not much you can do about shock, other than hope the plant survives.
- Too cold. If the plant is exposed to cold drafts, many tropical plants will begin to drop healthy leaves.
- Physical damage. Plants that are in high-traffic areas or are frequently brushed will sometimes drop leaves inexplicably. Pets and children rubbing plants can cause leaf drop.
- Pests. Certain pests, like mealybugs, can cause leaf drop. Check fallen leaves carefully for telltale signs of infestation. If you see pests, treat the plant and the leaf-drop should stop.