Hi there

I had blight last year on most of my tomato plants.
What is the best thing to do to prevent it this year?

Thanks

Del Rees

Our Gardens Expert replies:

Blight on tomatoes is a rapid spreading fungal infection that shows as lesions on the leaves and stems that quickly spreads onto the fruit turning them brown and eventually rotting the fruit. It is caused by a fungus called Phytophthora infestans. Spores are spread via the wind, and splashing rain. The problem is worsened by warm and wet conditions and spores can over-winter in the soil, but the likely hood of re-infection from the soil is far less than infection from air-borne spores. Potatoes can also be infected so it is important to dispose of all infected material including any seeds and not to add them to any compost bins you may have!

The safest way to avoid blight is to grow tomatoes in a greenhouse where the risk of infection is less than plants grown outside. You should employ preventative measures by using sprays such as Mancozeb or copper sprays, these should be applied before any signs of infection and don’t always work….but it might delay the spread of the disease long enough for fruit to develop and be harvested.

There are varieties that claim to be resistant such as ‘legend’ but there is no 100% guarantee…so try a few varieties and see which works best for you!

Sven