This year we seem to have been lucky with blight but I’ve had a few questions by email about blight. The one below I thought worth sharing since there’s more people with the same problems around and it sums up the questions I’m being asked.
Hi John, unfortunately our Sarpo potatoes have blight but later in the year than we have had on other varieties. Not sure about keeping qualities now. It hasn’t reached the potatoes yet so we have removed the tops. We are in Somerset and it has been warm and very wet. The tomatoes on the allotment( Outdoor Girl, have just got it too. Can I save them by picking green ones and freezing them for chutney? Due to extensive works on the kitchen cooking is out of the question.
Firstly, warm and wet are the perfect conditions for blight, see Smith Periods in this article on Potato Blight. The western areas of the British Isles being the wettest are often the worst affected by blight.
The Sarpo potatoes are resistant to blight but not immune. The problem is that the blight strains vary, just like the flu. So some years it will be unaffected but other years it will go down, although it’s often the last variety to succumb.
What To Do If You Have Potato Blight
- Once blight has a foothold sprays are useless and the only thing to do is to cut off the haulm (leaves). You can hot-compost the haulm but burning is safer. Don’t cold compost the haulm, it’s infectious.
- Leave the potato tubers in the ground for three weeks. This prevents the spores getting to the tubers and causing them to rot in store and also allows the skin on the tubers to harden which may help them resist better if spores do land on them.
- When harvested, rinse off the soil and dry the potatoes thoroughly before putting them into sacks for storage.
- Check them frequently whilst in storage and immediately remove any tubers showing signs of rot before it spreads.
Tomatoes being members of the same family as potatoes, Solanaceae or nightshade, are hit by blight although greenhouse crops often escape it as the spores don’t get to them. Like potatoes, once infected there is little that can be done to save the plants.
Any fruit that is unaffected can be rinsed to remove any spores on the surface and treated as fruit from uninfected plants, although I would suggest it best to process or eat quickly as the spores are in the air.
If you’re unable to use them promptly then by all means bag them up and freeze to make into chutney or soup etc. later.