Blossom end rot

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 Time to act in September

Do Time to act in October

Do Time to act in November

Do not Time to act in December

Blossom end rot is caused by calcium deficiency. Without calcium, a plant’s cell walls collapse and die, resulting in the bruised appearance of the fruits. Plants take up calcium from the soil through their roots, so if it’s dry, the calcium stays locked in the soil and the plant suffers. Acid soils always have low levels of calcium. If treated early, later fruits will go on to ripen successfully. The problem can also be triggered by applying fertiliser to dry soil.



Just when your tomatoes, peppers and aubergines are starting to ripen, they develop a mass of spots at the end of the fruit. These merge to form a sunken, leathery, dark brown area.

Find it on

tomatoes, peppers, aubergines



Don’t allow the soil around the plant’s roots to dry out. Water plants regularly, as even a short period of drought can encourage the problem. Compost sold specifically for tomatoes, such as grow bags, contains sufficient calcium for a good crop of fruits. Never apply fertiliser to dry soil, always give plants plenty of water first.