Do You Want to Harvest Tasty Vegetables All Winter Long?

Here Are 6 Ways to Winterize Your Greenhouse

It’s officially autumn, and that warm summer glow is beginning to fade. The leaves may be changing colours, and the nights are getting a little colder, but that doesn't mean it’s time to take a break from gardening. 

Planta greenhouses are designed to help you extend your growing season so you can continue to harvest tasty vegetables all winter long. Below you’ll find a list of tips to help prepare your DIY greenhouse kit for the winter.  


Customer image of the Sungrow 20

1. Clean Out Your Greenhouse

    As the fall season rolls in, this is the perfect time to give your greenhouse a deep cleaning and get organized for the colder months ahead. Take the time to give the polycarbonate panels a good wipe-down as this ensures the maximum amount of sunlight will reach your plants throughout the winter. In addition, you should clear out any plants that won’t survive the cold, clean off your benches, give your area a sweep, and disinfect all of your equipment. 

    2. Add Insulation

      Although the polycarbonate acts as a fantastic insulator, it may be wise to add another layer of warmth depending on where you live. Many DIY greenhouse gardeners use shade cloths or bubble wrap to help absorb the frosty cold air. It’s also wise to check for any cracks or gaps in the greenhouse and make sure they’re sealed in time so the warm air can’t escape.


      Customer image of shade cloth insulation in their Sungrow greenhouse

      3. Use a Heating System

      A heater is a guaranteed way to keep your plants safe from the cold winter chill. However, before the outdoor temperatures begin to drop, it’s essential to test your heater and cables to make sure that they’re functioning at their peak. In addition, having a thermometer handy will allow you to monitor the temperature accurately and ensure the indoor climate is perfect for your garden.

      4. Keep Things Ventilated

        In the winter, your DIY backyard greenhouse needs to be well-ventilated in order for it to maintain a healthy environment. Try opening the doors for a couple of hours on sunny days of 40°F and above (4.5°C), so your plants can get some fresh air. We also recommend having a fan running regularly during this time so that the heated air can circulate and minimize mould, mildew, or a build-up of other bacteria. Remember – your plants love the warmth, but they also need to breathe.


        Customer image ventilating their greenhouse in winter

        5. Use Plant Coverings

          Cold winter nights can be harsh on even the hardiest of plants, so it's essential to protect them from the frosty air. Tarps, horticultural fleece or row coverings can all help keep in the moisture and warmth during especially chilly nights. Just remember to take them off during the day so the humidity doesn’t build up, and your plants can soak in the sunshine. 

          Alternatively, bubble wrap is another excellent tool for plant insulation and doesn’t need to be removed. Clear bubble wrap will allow the sunlight to shine through the UV-protected polycarbonate panels and directly onto your plants. The best part is, by utilizing this form of a plant covering, the generated heat won’t escape as easily on the frostiest nights.

          6. Focus on Cold-hardy Vegetables

            Most importantly, you need to choose the right crops for winter. Although a greenhouse can allow you to grow all year round, that doesn’t necessarily mean that tropical heat-loving plants will flourish throughout the darker months. However, if you follow the above steps – the following vegetables should be able to comfortably grow as you move into winter:

            • Carrots
            • Beets
            • Radishes
            • Turnips
            • Onion
            • Garlic
            • Leeks
            • Parsnip
            • Rutabagas
            • Radicchio
            • Kale
            • Swiss Chard
            • Spinach
            • Arugula
            • Cabbage
            • Collard Greens

            Customer image of seed trays in their Sungrow greenhouse

            It’s important to note that plants grow a little slower in the winter than they would in the summer. But if you utilize these tips and have a little patience, your garden will thrive, and you’ll be able to enjoy tasty vegetables even in the middle of winter. 

            Do you have any other tips for winterizing your DIY greenhouse kit? Let us know below!

            Why Planta Greenhouses?

            Back to Learn