Cold Weather Gardening Advice

Cold Weather Gardening Advice

Posted by Claire Keen - Purple Sweet Pea on 21st Mar 2018

I would have loved to have written about all my lovely seedlings and potting them on this month but the weather across the UK has really delayed gardeners including myself this year. Working weekdays, I primarily use my weekends to enjoy my garden, but this year we have seen some really wet, snowy and cold winter conditions for a long period which are not the best for sowing seeds and growing strong plants.

Wet and cold conditions can be disastrous for some plants especially tender flowers and vegetables. Many plants 

need warm moist conditions to germinate. Cold weather affects plants in many ways including freezing the cells in a plant and causing damage that interrupts the plants biological system, which when working well allows water and nutrients to flow around the plants cell structure. This freezing is especially disastrous for newly germinated young plants, which need the best possible conditions from the start to ensure they develop into strong healthy plants.

Usually, March is my busiest month for sowing and by April I have a good amount of lovely seedlings to transplant. However, this year as many snowy, wet and cold weekends throughout March have come and gone, I’ve held off knowing, that many late sowed flowers and crops catch up quickly when the warm weather arrives.

I currently have some of my cut flower seeds including cornflower, cosmos and asters sown in the greenhouse inside propagators and also inside the house on sunny window sills. I have a few late sown vegetables including tomatoes, cucumber and melons which, I hope to move out in to a warm greenhouse when this cold weather finally decides to break.

If you want to battle on though the cold weather, there are a few tactics you can employ to continue to sow and grow your plants. However, be assured many plants will catch up even if you sow them a few weeks later than directed on the packets for your region. But if you can’t wait here are some ideas for keeping your plants and seedlings warm.

Heating your greenhouse

If you have a power supply, you could heat your greenhouse with an electric heater. If not, a better choice is a paraffin heater that also produces CO2 giving even more help to your plants as they grow. Another option, although I have not done this myself, is to construct your own heater by making 24-hour candles and placing under terracotta pots. However, to see out many days of cold you would need to create a lot of candles.

Grow Room

Some gardeners construct their own grow rooms inside. The basis being a large light proof box, coated with reflective material such as tin foil to reflect the light and heat provided by lamps. This method can allow you to grow crops all year long and sometimes more tropical plant varieties.

Heated propagators

Many gardeners use unheated propagators to start off seedlings in the greenhouse or sunny windowsills. However, if you want to invest you can buy heated ones that speed up germination and keep your seedlings warm and safe so

me say they even give better seed germination rates. Heated propagators usually have a heat mat or element inside that heats the plants from underneath.

If you are new to gardening it’s great to find out about looking after your plants by trying things out for yourself. One year, when I was relatively new to gardening I was particularly conscious of providing the right conditions for my lovely squashes. I had moved my squashes in to the cold frame to harden them off ready to plant out at the allotment. However, I was concerned about the temperature drop overnight. So much so, that I lovingly placed a number of hot water bottles under them until I was sure the temperature would not drop too low inside the cold frame though the night. It was a bit like tucking them up to bed. I did however through my unconventional hot water bottle antics manage to grow a lovely collection of squashes.

I’d love to hear how you are keeping your plants warm and healthy this year. Don’t forget you can keep up to date with our allotment and garden though our Vlogs on YouTube at

Take care