Informational table showing disease name, symptoms, pathogen/cause, and management of Tulip diseases. Disease Symptoms Pathogen/Cause Management Basal Rot Large spots on bulbs are dark brown. White or pink fungal growth forms on the bulbs. Flowers from infected bulbs are deformed. Foliage dies prematurely. Fusarium oxysporum f. sp. tulipae Do not plant bulbs that have white or pink fungus on them. Purchase and plant fungicide-treated bulbs. Fire Leaves may fail to emerge or may be stunted or deformed. The shoots may curl to one side. Dead spots are surrounded by dark green. Spots turn white or yellow and have small black granules (sclerotia) in them. Botrytis tulipae Purchase fungicide-treated bulbs. Apply a fungicide to protect plants. Pythium Root Rot
Bulbs have soft, gray spots with brown borders at the base of the bulb. Shoots fail to emerge. Pythium Plant in chemically or steam-pasteurized potting mix. Discard infected plants. Stem and Bulb Nematode
Bulbs have gray to brown patches that feel spongy. Bulbs feel lighter than normal at planting and the interior of the bulb is mealy in texture. Ditylenchus dipsaci Purchase and plant hot water treated bulbs. Discard infected bulbs. Viruses Leaves may be mottled, have yellow flecks or stripes. Flower color may break or flowers may be distorted. Many viruses are known including tulip breaking, tobacco necrosis, tobacco rattle, tobacco mosaic, and cucumber mosaic virus. Discard infected plants. Purchase virus-free plants.

Fire (Botrytis).

Blue mold.

Blue mold.