The Winter Polytunnel

Stephanie Hafferty
Wednesday, 23rd December 2015

Stephanie Hafferty explains how a polytunnel has multiple uses. From growing fresh vegetables across the colder winter months and helping to overwinter for spring growing, to drying washing and storing wood.

Working in the polytunnel on a grey, dismal December day as the rain fell steadily outside, offers the advantages of fresh air and and gardening without having to wear wellies and waterproofs.

December has been very mild here in Somerset so weeds are still germinating in the tunnel and hungry slugs are munching on some of my plants. There are even some tiny green caterpillars, probably baby cabbage moths. Therefore a good tidy and weeding session proved to be very worthwhile. I lost count of the number of slugs and snails that are now hopefully filling the beaks of hungry wild birds, finding far too many tiny ones as I ‘tidied’ plants (more about this later) and removed small weeds before they became a problem.

The weeds were mostly individual grasses, poppies and a few very tiny marigold plants. I mostly used my fingers and the tool below – a Nunki Weeder – excellent for removing small weeds around the small plants. It took just under 15 minutes to do the whole tunnel, most of that time taken up with the more delicate task of plant-tidying. I was having such a lovely time that I forgot to take photos of the weeds so I can’t show their size, but they were up to an inch/couple of centimetres, most of them so tiny they were barely above the soil.

My polytunnel, sitting where the lawn used to be when my children were younger, is 12 ft x 40 ft. It has straight sides and base rails, chosen because it meant I could get the maximum width possible in the space I have because I didn’t have to dig in the polythene. A few inches to the left of the polytunnel there is a concrete path and 18 inches to the right a hedge marking the boundary between my neighbours. It was a tight fit! The tunnel is laid out with one larger bed down the middle to make the most of the height – very important in the summer – and two narrower beds down either side. A huge advantage of a straight sided tunnel is that you can grow taller plants right up to the polythene. The two compost paths are easy to hoe and keep weed free – reducing habitat for slugs and other pests and also weeds, saving loads of time.

Since construction, the polytunnel has been entirely no dig.

The tunnel was planted out on October 16th using plants I had raised in modules – only the freesias were already growing there so the plants have been growing in ever decreasing light for two months.

This photo was taken standing at the doorway. As you can see, it is a multi-use polytunnel. Here I grow food, hang the washing to dry on wet days, saw firewood for the woodburner and overwinter plants that benefit from some protection from the weather but are not so tender that they need a frost free environment.

Having a dry place for the sawhorse and firewood waiting to be sawn – by hand, using a bow and wood saw – is invaluable during the winter. I appreciate having somewhere I can cut wood even on wet days. The sawhorse moves outside during the summer months to make space for more summer vegetables – I usually grow aubergine, pepper and chilli plants in the side beds then.

Next to the pile of free logs (collected with permission from skips: broken fence posts, off cuts, willow, some unidentified branches) the freesias are growing well. I think I planted these five years ago, just six bulbs then. The smell when they flower is incredible.

On the opposite side, plants which overwinter here are protected from the extremes of winter weather, in particular wind. Four blueberries live permanently in the polytunnel, mainly to keep wild birds off the fruit. Some garden herbs such as mint and thyme spend the winter here too, to extend their season. There are more pots on the central bed near the doorway, including one with oca – the experiment here is to see whether the tubers get bigger,as they can grow for longer than those I grew outside. Hopefully hungry mice won’t find them. A thermal fleece hangs close by, ready to be placed over the more tender plants if there is a cold spell.

The small table is temporary (I was using it to store chilli plants on which are now overwintering in the house) and will be moved soon, along with the trays. I want that space to be ready for planting of very early new potatoes next year.

At the back of the tunnel, an old dressing table makes a good place to sow seeds and pot on. As this door is close to a plum tree I only use it for ventilation, removing it during hot summer days for extra air flow, so this potting bench is a permanent feature. Here are sacks and tubs of potting compost and various soil enhancers I have bought including comfrey pellets, rock dust and Seamungus (I was trying that out this year, it is incredibly smelly) and some liquid seaweed and chicken pellets I was given. Comfrey is free and widely available where I live, however I bought some pellets to try out during a very busy time when I knew I wouldn’t have time to make my own comfrey liquid. The black container was rescued from a skip, I grow early potatoes in it. Above, hangs lengths of the bailer twine which tomatoes, cucumbers and other tall tunnel plants grow up during the summer – they are reused for years.

You can just about see a compost heap with trays of plants on top of a pallet at the bottom of my garden through the mesh part of the door.

During the winter, all of the pots and trays for sowing are stored in the greenhouse.

I grow Grenoble Red lettuce because Charles recommends it as the most productive and reliable for overwintering in the UK – all of these grown from seed saved by him. These lettuces will be productive right through until April or May, when I will want the space for summer crops.

Smaller rocket, mustard leaves, endives, pea shoots, spinach, beetroot, chard and kale leaves are mixed with the salad, the larger leaves used for cooking. There are also herbs – parsley, coriander, chervil – for salads and cooking.

This year I am growing spring cabbages inside for the first time at home. In between I have planted some garlic, which can carry on growing when the cabbage has been harvested and summer crops planted – the garlic is in two rows widely spaced to allow for this. Garlic grows well outside of course: I grow some undercover for larger bulbs.

Every few weeks or so I ‘tidy’ the plants, usually when picking, removing badly damaged or yellowing leaves. This is not just so the polytunnel garden looks nice but also because it reduces habitat for slugs, snails and other pests. All of this is collected in a trug and added to the compost heap.

I have also planted five elephant garlic cloves in the tunnel but have completely forgotten where! I thought I would remember and didn’t put a label in … I should have learned by now not to trust my memory. Hoping it will emerge soon so that I find it.

Other vegetables growing in here include spring onions and Broccoli Raab. This is going in a stir fry this evening, with some pak choi and other leaves, along with leeks and this summer’s garlic from the allotment.

At the front of the photo of the whole polytunnel above, you can just about make out rows of small carrot plants. These were sown at the same time as the other veg were planted, rather late in the year for carrots, so even though the germination has not been perfect we are very pleased with the progress so far and look forward to early fresh carrots in the spring.

I have some more carrots sown in late September in a large pot in the tunnel – they are looking healthy and will provide some small carrots soon.

Stephanie Hafftery is a master no dig gardener and blogs at She runs No Dig gardening courses with Charles Dowding.

Stephanie is co-author of No Dig Organic Home and Garden

Further resources

Watch: Living with the Land part 5: No-dig gardening

How to Create a New Vegetable Garden

How to Grow Food in Your Polytunnel all Year Round