The fact sheet HGIC 2103 "Flowering Bulb Diseases" is currently being reviewed and will be posted here as soon as it is complete.  The following is a transcript of the taped message on this subject which can be accessed by South Carolina residents using the Home & Garden Information Center's toll-free message system. 

Most diseases that can affect bulbs do not generally become a problem, if you start with healthy bulbs and plant them in sterilized soil. Some of the common problems that may occur include several types of bulb rots, viruses and nematodes.

There are various disease-causing fungi that live in the soil, which can cause bulbs to rot. Plants that are affected may be stunted and have yellow leaves. In some cases plants may fail to emerge. A whitish growth may be visible on the underground shoots and bulbs.

These diseases occur mainly under cool, moist weather conditions and in soggy soils. Remove and discard infected plant material.

Bacterial rot, or soft rot, may begin as a slow yellowing of the leaves often beginning at the leaf tips. Leaves may wilt, collapse and die. Bulbs and the base of the leaves decay and often have a foul-smelling odor. Soft rot is most serious in wet, heavy soils. Provide adequate drainage, and remove infected plants.

Viruses can infect plants, causing leaves or flowers to be mottled or discolored and growth to be distorted. Control aphids and other sucking insects, which can spread viruses. Dig up and destroy infected plants.