Monty Don, the renowned horticulturist and BBC Gardeners' World presenter, has issued a critical warning for UK gardeners about the increasing risk of potato blight in July. The fungal disease thrives in warm, humid conditions, which are becoming more common during the month. Don emphasizes the need for immediate action to protect potato crops.
Monty Don's July Birthday Tradition
Don, whose birthday falls on July 8, has a yearly ritual of digging first early potatoes for a celebratory meal. He notes that the harvest varies greatly depending on planting time and weather. However, he now primarily grows first earlies because they mature faster and are less susceptible to blight. He explains: 'One of my yearly rituals is to dig first early potatoes on July 8th, my birthday. The harvest varies hugely depending on when I planted them and the subsequent weather, but tradition demands I lift enough for a celebratory meal. I now only grow first earlies because the risk of blight is so great.'
Understanding Potato Blight
Potato blight manifests in two forms: early blight and late blight. Both can rapidly devastate plants and tubers. The disease develops quickly when temperatures are high and humidity persists for 23 hours or more. Don warns: 'The fungi develop very fast when the temperature is high and the air humid for 23 hours and these conditions are becoming increasingly common in July.'
Immediate Action Required
Don advises gardeners to act promptly upon noticing telltale signs: chocolate-colored circular areas on leaves that quickly spread and collapse. He recommends: 'Remove all foliage and compost it (the fungi do not survive the composting process) and make sure that there is a good soil covering over the tubers. Then wait for a dry day and harvest the crop.'
Preventative Measures
To minimize blight risk, Don suggests starting with blight-resistant potato varieties such as the Hungarian Sarpo range, Sarpo Mira, Cara, and Setanta. These are recognized for outstanding resistance to viruses and late blight. Additionally, gardeners should choose open planting locations with proper airflow, space plants adequately to allow foliage to dry quickly after rain, and practice crop rotation to avoid disease spore buildup in soil. Applying a protective fungicide from June, especially during damp conditions, and reapplying after a few weeks can also help protect fresh growth.
Impact of Blight
Blight can render potatoes inedible and unstoreable. Don emphasizes the urgency: 'The crop can be saved if the foliage is removed immediately after the tell-tale chocolate coloured circular areas of the leaves are noticed.' By following his advice, UK gardeners can safeguard their harvests and enjoy a bountiful July crop.
