UK blight risk map
Where late blight is building right now, region by region. Search your postcode or click any area for the week's reading.
Reading the blight conditions…
What you can do about blight
Once a plant has late blight there's no saving it — so it's all about staying a step ahead. The good news: a few simple habits tip the odds firmly in your favour.
Stay ahead of it
- Grow tomatoes under cover. A greenhouse or polytunnel keeps the leaves dry — the single biggest protection. Outdoor tomatoes are most at risk.
- Choose resistant varieties. Tomatoes like Crimson Crush, Mountain Magic or Cocktail Crush; potatoes in the Sarpo range (Mira, Axona).
- Give them air. Space plants well and strip the lower leaves so the breeze moves through.
- Water the soil, not the leaves — and in the morning, so any splashes dry fast.
- Grow earlies and lift early. First and second early potatoes harvested before the August peak often dodge it altogether.
If it strikes
- Act the same day. Remove affected leaves the moment you spot the brown, water-soaked patches.
- Bin them — never compost. The spores survive a compost heap; bag them or burn them.
- On potatoes, cut the lot. The second blight hits the foliage, cut off and clear all the haulm — it stops spores washing down to the tubers.
- Then wait to lift. Leave potatoes 2–3 weeks after cutting back so the skins set before you dig.
- Don't count on sprays. The old copper fungicides are largely off the shelves for home growers now — prevention is the real tool.
The full blight guide — spotting it, the Hutton Criteria, and resistant varieties →
What this shows: late blight (Phytophthora infestans) is the disease that turns tomato and potato leaves brown and collapses a crop in days. It thrives in warm, humid spells. We use the Hutton Criteria — the UK standard — which flags a high-risk “Hutton Period” when two days in a row each stay above 10°C overnight with six or more hours at 90% humidity.
A summer story:blight risk is mostly a June–September concern. Outside those months the map sits quietly green — we light it up the moment conditions turn.
Risk is sampled at points across the UK and refreshed through the day; each region is shaded by its nearest reading. Weather data from Open-Meteo. Map © Mapbox © OpenStreetMap contributors.