How to recognise it
The majority of bulbs will fail to sprout and those that do will have distorted leaves and shoots. The withered shoots may have a covering of grey mould with black fungal bodies (sclerotia) in damp conditions. Leaves will have sunken, yellowish spots surrounded by dark green, which will also developing on neighbouring plants as the disease spreads. The flower stalks may have elongated dark brown areas (giving the impression that it has been scorched by fire) with black fungal bodies (sclerotia). The buds may fail to open and have a white mould covering them, with small brown-white spots or blisters.
The bulbs will have small black fungal bodies (sclerotia) on the outside and inside the bulb the outermost scales may have sunken circular areas, sometimes with black fungal bodies (sclerotia) in them. In later stages the whole bulb may rot and have black fungal bodies (sclerotia) covering the outside.
Any flowers which develop may be spotted and will rot rapidly in wet weather.
Why it’s a problem
Affected tulips cannot be saved and must be destroyed. It spreads quickly (the fungal spores become airborne and move from plant to plant) and can rapidly affect an entire bed of bulbs. The small black fungal structures, the sclerotia, are produced on dead tissue and can survive for 2 to 3 years in the soil or on stored bulbs.
Where you are likely to find it
Generally identified as symptoms affecting planted and growing tulips, although the disease can also be present on stored bulbs. Occasionally this will also affect lilies.
How to prevent it
Infection is spread by planting infected bulbs, so ensure that any bulbs you store are free of any signs of this disease. You can use a fungicide to dust or wash bulbs prior to storage. Do not store any damaged bulbs as this makes them susceptible to infection.
How to get rid of it
Immediately destroy any infected bulbs as this can spread rapidly to neighbouring plants. A fungicide can be applied to neighbouring plants to try and reduce the chances of infection. Do not re-plant tulips on infected land for at least three years. If you must re-plant within three years then dig the soil deeply so that the upper layers are buried below the planting area and plant bulbs shallowly.
Is it good for anything?!
Other useful information
The disease is called ‘tulip fire’ due to the affected leaves and stalks looking as if they have been scorched.
Tulip grey bulb rot can also lead to patches of tulips not sprouting.