Watch out for fungal diseases this month

The recent warm, damp weather has provided the perfect conditions for fungal diseases – powdery mildew, blight, leaf spot and plenty more.

Below are some images of common problems to help you identify them. The treatment is generally the same regardless of which fungal problem your plants are dealing with. Bear in mind that this is the time of year that many plants naturally get affected, so tolerating it to an extent is advisable. But if things get bad, try the below:

  1. Remove/burn affected foliage & crops as quickly as possible to prevent spread (don’t just add it to the compost pile)
  2. Try to create a bit more space for air to circulate between plants – it may be that you decide to pull up a couple of plants and sacrifice them
  3. Be careful when watering not to spray the leaves with water.
  4. Keep soil healthy and nutritious so that the plants are stronger and can fight disease naturally – adding a mulch or liquid feed can help.
  5. Harvest what you can before the disease takes over – for example, pull up leeks before the main shaft is affected, harvest tomatoes before the fruits are affected etc etc

An exception to the above: Chocolate leaf spot in younger transplants

You can expect them to grow out of it quite quickly once they’ve got their root system down – for example you may receive spinach or chard plants with a few spots here and there…they should soon produce healthy new leaves at the centre.

Leaf Spot

Blight on Tomatoes

Powdery Mildew (squashes & courgettes)

Alternaria Leaf Spot (on brassicas)

Leek Rust

Downy Mildew (squashes etc)