How do I control Potato Blight?

Q: How do I control Potato Blight?

What is it?

Potato blight is devastatingly destructive and can wipe out your potato and tomato plants overnight. It was responsible for the Irish potato famine in 1845. It's also a tricky individual as, like many bugs such as our own common cold, it is mutating and adapting all the time. I have to say it's also hard to control.

What it looks like:

Don’t be surprised if you suddenly find your plants infected. It can happen overnight following a spell of warm and wet weather. Watery spots on leaves soon develop and start to rot. Brown lesions on stems can develop, eventually resulting in rotten tubers or fruits.

How to prevent or treat:

First up, you can try growing blight resistant varieties of potato and tomato. Work is ongoing at breeding stations around the world and various strains of potato and tomato are now available which are resistant to blight. Remember they’re resistant and not immune - you may still get a slight attack but nothing on the scale of other susceptible varieties.

Another good tip for reducing the severity of an attack is to keep the leaves of your potatoes and tomatoes dry. Obviously, this is impossible in rainy weather but if you ever have to water by hand only wet the soil. Never stand there idly spraying water over the canopy of leaves because the spores of potato blight need water on leaves to move.

Covering plants in times of blight attack can reduce infection but will not stop it. You can always avoid potato blight by only growing early varieties – ones that crop before late summer when blight is more prevalent.

Blight is a bit of a headache for gardeners who love growing their own spuds and toms. But good gardening practice and an eye on the weather will reduce infections. 

Garden Pests