A blighted tomato plant with rotting fruit and withered leaves

Tomato blight

Learn how to recognise and tackle tomato blight, in this expert guide.

A table displaying which months are best to sow, plant and harvest.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Time to act
Time to act

Do not Time to act in January

Do not Time to act in February

Do not Time to act in March

Do not Time to act in April

Do not Time to act in May

Do Time to act in June

Do Time to act in July

Do Time to act in August

Do not Time to act in September

Do not Time to act in October

Do not Time to act in November

Do not Time to act in December

Tomato blight, a fungal infection called Phytophthora infestans, spreads by wind and water-splash. It also attacks potatoes and is triggered by warm, wet conditions, making outdoor tomatoes more susceptible than those in a greenhouse. The crop is quickly ruined and even if it’s immediately picked you can’t stop the tomatoes rotting.


In this clip from Gardeners’ World, Monty reveals the tell-tale symptoms of tomato blight, and how to deal with it. Find out how he salvaged the remaining crop and what you should do with blight-affected plants to limit any further spread of the disease:


Ripening tomatoes develop brown sunken spots, which spread to the leaves and stems.

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Remove blight-infected plants as soon as they are identified, to prevent spread to other plants.



Since most copper fungicides have gradually been withdrawn from sale, there are currently no chemical treatments available for use on blighted tomatoes.