Basal rot

Symptoms - This is one of the most serious diseases affecting narcissus, and it occurs in most soils. The fungus infects bulbs through bulb roots or small wounds, made usually when the bulbs are lifted. Bulbs can develop brown discoloration and softened tissue. Rot spreads, scales turn reddish brown, and a pink-white fungus is seen on affected tissue. Eventually bulbs become brittle, shrink and dry out or mummify. When already planted out, Narcissus lack flowers and the foliage is sparse, yellow and stunted.

On Crocus the plant become yellow and the foliage dies. If you lift the bulbs, you will see a rot spreading through the bulb.

Storing bulbs and corms in warm temperatures (more than 22oC (72oF)) can also encourage rot.