Only you can promote its welfare. If you fail to do that effectively, you are likely to be your plant worst enemy. Common Houseplant Diseases Diseases Description Favored by Powdery Mildew White powdery coating on leaves, buds and stems Too much humidity associated with poor air circulation. Roots rotten and decay. Stems and crowns watersoaked and darkened at soil level.
Stems collapse or wilt and die.
Poor drainage or overwetness and excessive soil compaction. Damping-off Fungal caused. Seedlings turned dark at the soil level, eventually rot and fall over. Gray Mold or Botrytis Blight Fungal caused. A whiskery fuzz of gray mold covers young foliage, flower buds or flowers, usually causing them to become damp and decay.