Even for the most experienced gardeners, deciding on what to grow in your greenhouse can seem tricky. Especially during the winter months. There are endless fruits and vegetables at your disposal, but it’s not always easy to know which ones to buy. Or even how to grow them!
Greenhouses and even garden sheds can provide protection against harsh conditions during cold weather. A greenhouse can provide you with the perfect gardening conditions to allow your fruits and vegetables to survive even the coldest weather.
If you’re looking for ways to make the most of your winter greenhouse during the coldest months of the year, then you’ve come to the right place. Let’s get started!
Winter Greenhouse Gardening
Through the autumn and winter, make sure you don’t leave your greenhouse completely empty. Instead, this is the perfect time to take advantage of the warmer conditions inside the greenhouse. These can help protect your plants from frost, whilst allowing you to grow hardy crops, like salads and herbs through the winter months.
During the colder months of the year, focus on ensuring your plants get plenty of light. This is because the light levels are low going into late winter and there are fewer daylight hours. You can do this by removing any shading material and cleaning the glass to reach the maximum light available. Perfect for plenty of natural light.
What to Expect
During winter, plants won’t grow as fast as they do during the summer months and often they won’t thrive in the same way. Some plants might not reach their full potential at all. Although they will still be a good harvest despite this.
You might also find that various plants won’t make any progress at all during some weeks. Especially in December and January. As long as these plants don’t die, as soon as the temperature warms up, they’ll continue to grow and bloom!
Vegetables to Grow in Winter Greenhouse
1. Hardy Herbs
In the winter months is best for you to transfer all of your herbs and mini plants into pots. Then bring them into the greenhouse, allowing them to develop and continue growing all winter.
TIP: Planting several pots of each will allow you to harvest what you sow in succession for a continuous supply.
Here are some great herbs you can plant and grow in the cold winter months:
- Garlic bulbs
- Lemon Balm
- Greek Oregano
- Winter tarragon
All of these are hardy vegetables, plants and herbs, able to survive in even the coldest of months. You could pick one or more of these and have a successful winter harvest.
2. Winter Greenhouse Salads & Vegetables
If you’re looking for a winter greenhouse salad, sow in trays or pots of compost. Then you can start planting the seedlings into large containers, border soil, or even this year’s growing bags. As for the plants, you could try hardy winter lettuce, such as ‘salad bowl,’ including rocket, pak choi, mizuna, lamb’s lettuce and spinach.
There are so many other great winter salads you can grow:
- Snow peas
- Warrigal greens
There are plenty more hardy winter vegetables that are best grown in the colder months. Maybe plant one, or try a few more!
These are some of the most popular winter vegetables you can grow. They’re able to grow in sacks or large pots. It’s best to try filling your container with two parts of garden soil to one part compost for optimum results.
Potatoes which begin growing during the earlier winter months will be ready to harvest and enjoy by March. You may also begin growing them earlier and move them outside when the weather starts warming up. Perfect in time for spring!
TIP: Keep in mind that they can also be susceptible to frost, so make sure to keep your greenhouse nice and warm when the temperature drops significantly.
If you need an excuse to try having more salad at Christmas, winter lettuces are the perfect addition. Winter lettuces like little gem, rocket and lamb’s lettuce prefer cooler environments. This makes them perfect for growing in the cold winter months.
There are plenty of varieties of lettuce you can grow during the winter. All you have to do is find the best one for you and you’re ready to add your all-important leafy greens!
5. Pak Choi
This oriental vegetable is a perfect addition to any stir-fry or noodle dish. Not only is it packed with healthy vitamins, but it’s also fast to grow! It can be sown as late as October, and it’d still be ready for winter harvesting.TIP: Leaves take roughly 30 days to grow, compared to 70 days for the full plant.
6. Spinach and Kale
Kale and spinach can grow well together in winter, even if the temperature drops to -5 Celsius or below. Both of these plants will usually be ready for harvest within 50 to 70 days.
You can harvest entire plants early if impending heat is likely to force them to set seed. Once both kale and spinach set seed, the foliage turns bitter and inedible.
7. Cabbage and Broccoli
When you manage to keep your greenhouse at the optimal temperature between 7-13 degrees celsius at night and between 10-21 degrees celsius during the day, both cabbage and broccoli can grow throughout the entire course of the winter season.
By planting them early, for instance, mid-winter time – they’ll be ready for planting outdoors in spring!
8. Brussel Sprouts
Brussels are one of the winter greenhouse gardening staples. They usually take around three months to grow, so you can harvest them in March when they’re roughly 1-2 inches in diameter.
If you wish to use them for cooking, make sure to harvest the sprouts that are of a similar size. This is to give them a more uniform cooking time.
When carrots are planted in late autumn, they can already be harvested as soon as the ground starts to defrost. If you’re having a good winter and when the icy ground melts once or twice before spring, check your carrots and they may be ready.
TIP: There are a wide variety of carrots, so you’ll want to make sure you get the cold hardy ones.
Beans are perfect because they’re both easy to grow and high producing. Meaning you’ll get a vast supply of this vegetable through the winter months.
Winter field growing beans for example thrives best in well-drained soil and full sunlight. This plant is frost tolerant, meaning it can survive through frost. Although, as the soil temperatures reach that of 9 – 12 degrees Celcius, you’re likely to find the plant will die.
There are plenty of other beans you can grow in winter as well!
If you’re looking for a more impressive plant, a cactus might be perfect for you!
Although this plant does prefer sunny and warm spots, it can also survive through cooler temperatures. In fact, it’s known as a plant that’s very hard to kill, so this plant is a safe option for even the simplest gardeners!
Make sure you take a look at how to grow a cactus and learn everything you need to know before diving into planting one of these!
Keeping the Heat In Your Winter Greenhouse
Your greenhouse can be the perfect place to grow vegetables, herbs and other plants in winter. However, keeping the heat in is key, especially in an unheated greenhouse. There are various ways to help heat your greenhouse and keep your greenhouse air temperature above that of the cold temperatures outside.
Passive solar plastic bottles are an excellent cheap alternative to electricity in keeping your greenhouse warm throughout the colder months. All you have to do is to paint the plastic bottles black and fill them with water.
The black paint will help in absorbing heat during the day. While at night, the stored energy is released automatically, which will heat the greenhouse space. For best results, you should place them around your wooden greenhouse or aluminium one. Try putting them on the wall or shelves.
To create a warmer greenhouse environment for your plants try using fabric row covers. This will also help to reduce heat loss for your greenhouse in winter. This is especially crucial for seedlings, as they tend to be more fragile.
Placing straw bales around your greenhouse can help with keeping the heat in. Although it may not add extra warmth, it will definitely help to reduce heat loss. This is crucial for your vegetables’ survival.
Regular packing bubble wrap also makes for an excellent insulator. You can layer your potted plants or vegetables and seed trays around the inside of the greenhouse walls and frame. Or, wrap the individual pots to keep the roots warm enough.
Winter Greenhouse Maintenance
Heating your greenhouse at night is as important as it is during the day, but it’s also important to keep track of the temperature inside. This way you’ll be able to tell if your insulation isn’t working or to tell if it’s getting too warm as we go into late spring and even into late summer when we get some warmer temperature.
Ensure a thermostat is working correctly to maintain the minimum nighttime winter temperature. It’s also best to invest in a minimum/maximum thermometer to monitor the winter weather conditions. You also want to clean your greenhouse’s gutters and water tanks.
TIP: It’s also important to make sure you have proper ventilation so the air inside doesn’t become stale with a lack of air circulation.
Gardening in a Greenhouse Benefits
- Ultimate Weather Protection – They provide your plants with a level of protection against harsh weather conditions.
- Pest Prevention – They can be exceedingly beneficial in protecting your plants against pests and predators – such as birds and insects – from eating or attacking your plants.
- All-season Gardening Place – You will have a designated area for gardening.
- Multiple Purposes – Thanks to the warmer and more humid environment that it provides, you can grow fresh, organic vegetables, flowers, bulbs and houseplants, including exotic plants and much more!
With all of this information to take in, you’re now ready to delve into the world of winter gardening and impress everyone around you with how much of a great gardener you are.
If you’re just starting out, why not take a look at all of our available greenhouses and garden sheds below! Maybe even treat yourself to a new one this Christmas. Ready in time to grow those all-important Christmas winter crops, then get yourself ready for the warmer months and summer crops too!Shop Greenhouses
You should start planting the seeds around 6 to 8 weeks before your average last frost date. Some even need planting as early as 10 weeks prior. You need to know your first average frost date to be able to work out when your last average frost date is. Then you can start planting. Growing in an unheated greenhouse can be simple!
Besides the above insulation options, having a polycarbonate greenhouse can be another great cheap alternative to heating your garden building. There are plenty of advantages of polycarbonate greenhouses!
Yes. Your greenhouse is the perfect place to grow crops all year round. Take a look at the variety of warm-season plants you can grow!