When you’re preparing your greenhouse for winter, the most important factor is whether or not you will heat your greenhouse. If you heat your greenhouse, you can use it to move some of your outside summer plants too, so they can survive the cold winters. If you don’t heat your greenhouse, check which plants can grow in colder climates. Some of our tips underneath will help you protect your plants.
1. Clean your greenhouse
Although I’m not particularly a fan of cleaning, this is one of those jobs that just needs to be done. Especially when the outside of your greenhouse is getting a little green, it’s important to get the windows clean. During winter, the light needs to be able to reach your plants and the sun needs to heat up your veggies whenever it gets a chance. For the outside it’s best to use a product that will also clean off the moss and fungi on your glass or polycarbonate cover. Make sure you get a different product for the inside, as this will be to aggressive to clean with so close to your plants. For the inside, try to find a biologically degradable product with no chemicals in it, so it doesn’t harm your veggies and plants.
2. Preparing the soil
When you are preparing your greenhouse for winter, you need to get the earth ready too. Start by removing all dead plants and plants that might have picked up a disease during spring or summer. Placing some worms in the soil of the greenhouse will help you to make the ground more airily and healthier to start planting again in spring.
3. Unheated greenhouse during winter
When you don’t have a heating system for your greenhouse, it doesn’t mean that you need to empty it during winter. There’s lots of vegetables that can grow during winter, as long as you use some of these easy tricks.
First things first. By the end of autumn you need to start planting your winter greens, such as spinach, leek and carrots. Make sure you plant before frost hits, because you won’t be able to dig in the ground when the soil is frozen.
Make sure your greenhouse is located on the place in your yard where the sun will shine during winter, this can sometimes differ from the sunniest place during summer (trees can give shade during summer but not always during winter).
To protect your greenhouse from frost, it’s advised to insulate your greenhouse. We have a whole article on insulating your greenhouse during winter (and summer for that matter). Take a look and increase your chances on yummie vegetables during winter.
To protect your plants from frost, make sure you put an extra cover over your plants. Each layer will make them better protected against frost and will ensure your greens to grow, even during cold winter nights.
Even during winter, it’s important to ventilate your greenhouse. Open your windows and doors only during sunny periods and when it is not freezing. Make sure you ventilate as often as possible, you don’t want to air inside to become too humid.
When your plants are ready to harvest, make sure you wait until the sun’s out. If you harvest frozen plants, they will break and all your hard work will go down the drain. Wait until the sun’s at its highest point and harvest your crops.
Most plants don’t really need watering during winter, especially not when it’s too cold. Water your plants during autumn and then during warmer winter days every 2 or 3 weeks, but keep it very low key. Most plants are asleep during winter, so they don’t need much water!
4. Heated greenhouse during winter
A heated greenhouse during winter will give you the opportunity to grow a wider range of vegetables and plants and to start growing spring vegetables earlier than in an unheated greenhouse.
When you have a heated greenhouse, you can use it to have your plants survive winter, so you don’t have to start from scratch during summer. You won’t make it as warm as a greenhouse would be in summer, the focus is on keeping frost out, so your veggies and plants don’t freeze and you can enjoy fresh homegrown vegetables all winter long. In our article on greenhouse heating you find all info about how to heat your greenhouse.