Cold Summers: How to Help Your Heat-Loving Crops Thrive

We wait all year for summer, only to get a few lukewarm days, a stubborn northerly breeze, and clouds that look more November than July. Sound familiar? If you’re trying to grow tomatoes, peppers, aubergines, or courgettes, a cold summer can feel like the ultimate betrayal. But don’t throw in the trowel just yet, there are ways to help your heat-lovers find their groove, even when the sun’s playing hard to get.

Fleece Isn’t Just for Frost

Don’t pack away the horticultural fleece after spring, it’s your best friend in a cool summer too. Draped over hoops or directly over plants on particularly chilly days or nights, it helps trap heat and create a microclimate your crops will actually enjoy. I’ve kept chillies flowering well into August under fleece tunnels when the rest looked like they’d called it quits.

Think Black: Warm the Soil

Black plastic mulch or dark paving slabs placed around your crops can help absorb and radiate heat to the surrounding plants. It’s a simple hack, but surprisingly effective. You can line the base of your greenhouse tomatoes with dark slate tiles and the difference in soil warmth is instant.

Feed for Flowers and Fruit

Cold soil slows root activity, and sluggish roots mean fewer flowers. Counter this by giving your plants a gentle boost with potassium-rich feeds like comfrey tea or tomato feed. Skip the nitrogen-heavy stuff, it’ll give you big leafy plants and very little fruit, which is not the goal.

Go Up, Not Out: Embrace Microclimates

Grow vertically near south-facing walls or fences that radiate heat and offer wind protection. If you’ve got a greenhouse, polytunnel, or even a sunny conservatory, now’s the time to make the most of it.

Pinch, Prune, and Prioritise

When summer’s short on warmth, your plants need a nudge in the right direction. Regularly pinch out side shoots (especially on tomatoes), prune excess foliage, and focus the plant’s energy on producing and ripening fruit. You may not get a huge harvest, but you will get quality over quantity.

Don’t Give Up, Adapt

Gardening in the UK means embracing unpredictability. One year it’s drought, the next it’s soggy and cold. Flexibility is your superpower. Use cloches, containers, and fleece. Protect from wind. Move pots to warmer spots. And most importantly, don’t give up because the thermometer refuses to cooperate.

 A cold summer might not be what you hoped for, but it doesn’t have to spell doom for your heat-loving crops. With a bit of creativity, some smart feeding, and a willingness to experiment, your tomatoes can still blush red and your chillies can still bring the heat, even if the weather won’t.