Amaryllis Bulb Rot

Fungal Disease

• A fungal disease called red blotch or leaf scorch attacks amaryllis bulbs that are grown outside, usually those in shadier areas, or those that frequently get hit by a sprinkler, according to TheFlowerBulb.com. Eventually, red spots form on the leaves and flower petals and the area is weakened and may break at the point of attack. Dark reddish spots will appear on the bulb and can develop into rotted areas. Destroy infected bulbs, as the fungus will reappear on new growth from the infected bulb.

Overwatering

• Overwatering is a common cause of bulb rot. Water an amaryllis only when its top 2 inches of soil are dry, according to the University of Minnesota Extension. If excess water drains into the plate beneath the plant, empty it promptly to discourage rot.

Prevention/Solution

• Good drainage is the key to preventing rot. Be sure to plant the bulb in a pot that isn't more than an inch larger than the bulb, as the excess soil will retain too much water. Use a well-draining potting soil. North Dakota State University Extension recommends a potting soil consisting of "equal parts garden loam, peat moss and Perlite or sand."