Little tricks about how to protect your precious seedlings during frosty nights.
I hope all of you enjoy this wonderful spring time right now and you got your cool season crops planted and seeds sown. It's a tricky time, I know. You're most likely always worried, if it wasn't too early to start and what if it get cold again. I know, I'm in it with you. If you followed My Nordic Garden on Instagram or Facebook during the past days, you saw me checking on my newly planted baby plants, always worried how they did after a frosty night. Sometimes we just need to let go and trust the plants. They are less temperature sensitive than we are - if you plant the right ones that is:
Cabbages, Cauliflowers, Broccoli, Lettuces, Pac Choi, Brussels Sprouts, Kale - they are all fine with -1 or -2 C at night without being covered. The same accounts for the seeds of carrots, kale, radishes, mustards or beets. But what if the temperatures drop into deeper freezing temperatures around -5C and below? Then we should act to protect our plants. A lot of our clients and friends were asking me lately this very question, that's why I decided to this post today. Keep in mind this rule of thumb: 1 layer of cover protects against -5C. From my experience, better be safe than sorry and put more layers on if you don't know how cold it will actually get. It's important to put your cover as close to the plants and the soil as possible, since it's actually the thin layer of air you create that keeps the plants warm. So more layers of cover means more layers of air in between, means more protection :-) And here we go:
The simplest (and often fastest to buy) is a painter's drop sheet. It's the clear plastic you'd use for renovation. You can use it to cover your beds easily and you can usually buy it at Canadian Tire or the like. It's not UV-resistant but does the job as a frost protection very well.
There are also floating row covers, you can get at different thicknesses. Like these: Floating Row Covers | Veseys from Vesey's. I use them for my hoops and cold frames and the thin one in the summer to protect my cabbages from the white cabbage butterfly and her caterpillars.
If you have no chance to run to a store or if it's too late to order something, just get an old blanket, bedcover or even thin pillows or sleeping bags and throw them over your beds. Just make sure, your plants don't get squished (place some sticks around, where the blanket can rest on).
Did you move lately or got a delivery from amazon? Perfect! Keep the bubble wrap! It's an excellent insulator for your plants due to the little air pockets.
You can also fill up old plastic bottles (like the big milk or juice containers) and fill them with water. Put them next or even around tender plants and cover the area with a blanket/row cover. The trick is, that the water in the containers takes a long time to freeze. During this process it submits heat to the surrounding area and therefore works like a little heater next to your plants. Hands-on physics in your garden!
Cover your plants in a thick layer of straw or evergreen branches for the night. Any sort of mulch is helping to buffer the cold as well.
Last but not least: put buckets, containers or big bottles directly over individual plants. If it's going to get really cold, add some row cover/plastic/bubble wrap or straw before you put the container over it.
And please!!! Don't put your tomatoes, peppers, eggplants and any warm season plants outside yet. Even in the unheated polytunnel or greenhouse - they will most likely get frost bites! Believe me, I tried it out :-) Wait until you last day of frost past - which is mid May for Ottawa and around May 25th for Hawkesbury and the rural areas between Montreal and Ottawa.
I hope I could help you with these tips so you can protect your little plants until all the danger of frost is over. It's just 3-4 weeks to go now!
Have a wonderful spring time and Happy Gardening!