It’s hotting up in Martin Fish’s polytunnel!
Warmer soil means it’s time to get my early vegetables started
It’s certainly far too cold and wet outside in my garden to even think about getting started with vegetables, but in the polytunnel it’s a different thing. Even without any artificial heat, it’s surprising how different it feels undercover, and the soil is now gradually starting to warm up.
When the sun shines it feels lovely and warm and some of this heat is transmitted into the soil, which acts like a storage heater and helps keep the air a few degrees warmer at night. Already the soil is around 7C (45F) and rising, which is two or three degrees warmer than outside in the garden. Having the polytunnel allows me to start growing around four or five weeks earlier than I’d normally start in the garden, which is a great bonus. It’s lovely to potter on a fine day, assisted by my dog, Molly.
Back in the early winter I forked in a few inches of organic matter to keep the soil in good condition, and to prepare for sowing and planting I’m lightly forking it over again and raking to create a fine seed bed.
I’m growing vegetables that will withstand slightly cooler conditions, such as early varieties of carrots, beetroot, spring onions, lettuce and other salad leaves. I’m also planting some first early potatoes which should be fine, as by the time the tops start to push through the soil it’ll have warmed up even more.
Of course, early sowing and planting undercover without heat still has its risks and if we get really frosty weather, it will freeze in the polytunnel. To protect my newly sown seeds and potatoes I’ll cover them with some garden fleece for added protection and keep my fingers crossed. I’m happy to take the risk for the reward of some tender veg a few weeks earlier than from the garden.