Welcome the First Tunnels Growing Guide. We know how to make great polytunnels, how to construct polytunnels and tailor a polytunnel to an individuals preference but we’re not gardening experts. Thankfully we work with several of the countries leading polytunnel gardeners, people who have been using our polytunnels for years. Each month this year we will produce a growing guide working closely with Mark Gatter, author of 'How to grow food in your polytunnel'. Mark has years of experience and has kindly offered to share some of the hints and tips he’s picked up over the years
Select Your Growing Guide
November is a quiet month in the outside garden, while in the polytunnel a wide range of crops continues to thrive – unless you forgot to add some frost protection. If you didn’t address that yet, you should do so now. Otherwise, a single night of frost may kill or seriously damage many of the polytunnel crops – lettuce, pak choi, radish, Chinese cabbage, celery, rocket, mustard greens and chard – that you are hoping to harvest during the winter and early spring.
I use fleece cloches, each made from a strip of horticultural fleece about 2 metres wide and about a metre longer than the bed at each end. Hoops of 25mm-diameter are held in place across the bed, every 1.5m. I tie Bamboo canes along the top to create a ridge, adding strength to the structure as well as support for the fleece. The fleece is then draped over the whole thing, and the extra length hangs down at the ends to enclose the protected area. See ‘How To Grow Food In Your Polytunnel’ for pictures of a fleece cloche in place and detailed instructions on making one.
Because fleece prevents a few percent of the light hitting from getting through to the plants beneath, and also as it restricts ventilation, it isn’t something that should stay in place over the beds during warmer weather. My design is tied to bamboo stakes on the far side of the bed, and strings are tied to it at intervals along its near side. Then I can lift the fleece and push it back out of the way, or pull it into back position again quickly and easily.
I normally set up my frost protection by the end of October, but that’s because I like to stay a step or two ahead of January and February, usually the coldest months in the UK. They then stay in place until mid-April.
If you have an automatic watering system in place it’s a good idea to shut it down at the beginning of the month. Your plants will need far less water during the winter than the rest of the year, and closing the system gives you the chance to clean and maintain it as well as preventing frost damage.
Keep some water near to hand in your polytunnel, as during the winter it can act as a heat sink and help to keep the internal temperature just that little bit higher. A water butt is ideal, and once the weather warms up again you’ll be even happier you installed one – they’re great for watering seedlings while you figure out where to put the automatic system.
If you plan on heating your polytunnel over the winter, there are several options. Unfortunately polythene doesn’t hold heat quite as well as glass. However, if you put up a layer of bubble wrap inside your polytunnel you can substantially increase the insulation properties of the cover, and reduce heating costs. Polytunnel heaters run on bottled gas, paraffin, or electricity. The first two generate water as a by-product and the polytunnel will require more ventilation as a result, while electricity is the most expensive option of the three.
Continue to add compost to any bare patches that appear in the beds as you harvest your winter crops.
Broad beans, cabbage, coriander, garlic and elephant garlic. November is a great month for sowing garlic and elephant garlic, both of which need a period of cold weather to develop a good root system, leading to really big bulbs the following year.
Aubergine, beetroot, cabbage, carrot, cauliflower, celeriac, celery, chard, coriander, courgette, cucumber, daikon, dwarf French and French beans, fennel, kohlrabi, lettuce, pak choi, pepper, radish, rocket, spinach, spring onions, strawberries, sweet potatoes, tomato, turnip.
You’re unlikely to get either courgettes or cucumbers to continue right until the end of the month, but you never know...