Tulipa sp. (Tulip) tend to get Botrytis (the leaf infection is called "tulip fire"), bulb rot and a mosaic-type virus disease. Discard rotting or moldy bulbs. Eradicate virus infected plants. Fungicides and sanitation are helpful for Botrytis.
Written by James Schuster, Extension Educator, Horticulture, and reviewed by Bruce Paulsrud, Extension Specialist, Plant Pathology and Phil Nixon, Extension Entomologist, University of Illinois at Urbana-Champaign.