When a jade plant loses its leaves, it can mean that its sun, soil, water, or fertilizer needs aren't being met, among other issues. Ahead, gardening experts share the common reasons a jade plant loses its leaves—and how to save it. Inspect your jade plant regularly to treat pest infestations as quickly as possible. DiseaseFungal diseases, which are often caused by excess moisture, can cause a jade plant to drop its leaves. To prevent your jade plant from contracting fungal diseases, Singh recommends reducing watering and improving airflow.