Do not allow fertilizer to contact the leaves. Water thoroughly after fertilization to prevent fertilizer burn. Caladiums are not drought tolerant and should be watered on a regular basis. Most home gardeners prefer to remove the bloom since it takes away energy from the foliage and reduces tuber size. Several bacteria or fungal organisms cause tuber rot.
Bacteria cause a soft, slimy decay, while fungi cause a dry, chalky rot.
To reduce the potential of tuber rot, select disease-free tubers for planting and store tubers properly to avoid high humidity and cool temperatures. Never store caladium tubers in the refrigerator. Tubers purchased in early spring, before ideal planting time, should be held at room temperature. Follow soil and planting procedures mentioned previously. An anthracnose fungus can cause the lower leaves to develop light tan to brown spots.