What is frost resistance?

Frost resistance is the ability of a plant to survive temperatures below 0°C without damage. When air cools, dew forms on all surfaces exposed to that air. When the air is below 0°C, ice crystals form. We speak of light frost between 0°C and -2°C, below -2°C we speak of hard frost and below -4°C is very dangerous territory for most vegetables.

Why are some plants more resistant to frost than others?

Frost or freeze damage occurs when the water in the cells of the plants expands. Everyone has experienced it. A bottle of water or wine is left in the freezer and boom! It is a bit the same principle with vegetables. But that does not explain why some plants are more frost resistant than others. The reason lies in the composition of the water that is stored in the plant cells. Vegetables that do well in the cold or frost are vegetables that naturally produce a lot of sugars. That sugar is also in the moisture of the plant cells. Sugar water freezes at much lower temperatures than normal water. And that is the reason why my pepper plant is now brown and dead and my cauliflower stands proudly upright as if nothing happened. Ever heard that celeriac and parsnips taste better after the first frost outside? This is because the plant defends itself by producing a shot of sugar when it gets too cold for them. And that sugar makes the vegetables tastier. In addition to sugar, smaller, lower varieties can benefit more from the heat that the soil has stored during the day and releases at night. Another rule: a mature plant can withstand frost better than young plants. Healthy plants in good soil also succumb less quickly than thin, weaker plants. Humidity can also help protect your plants. Humidity retains heat and insulates the air. That is why clear nights are also the coldest. You can buy seeds in all vegetables that are better suited for cold temperatures. You have the Meikonigin in lettuce, the Berlikum in carrots , the cauliflower Walcheren , ... These are varieties that meet the above criteria (produce sugar, lower varieties, ...).

Ensiling

Crops that can withstand frost can easily be put back in the ground after harvest with some soil left over. Think of beetroot , carrots , leek , radishes or parsnips . You can dig them up when you need them. Be careful though, when it gets warmer they will shoot up again and lose their flavour.

A list of vegetables and their frost tolerance

(additions are welcome below this article)

Damaged by light frost in the vegetable garden (down to -2°C):

Beans , Corn , Cucumber , Eggplant , Melon , Okra , Peppers , Paprika , New Zealand Spinach , Pumpkin , Tomato , Pineapple Cherry , Watermelon , Courgette . Note that the fruits tolerate light frost slightly better than the plant. The fruits can tolerate up to 2 times light frost.

Can withstand light frost in the vegetable garden (down to -2°C):

Artichoke , Pak Soy , Cauliflower , Celery , Chinese Cabbage , Garden Peas , Broad Beans and Radicchio .

Can withstand hard frost in the vegetable garden (less than -4°C):

Broccoli , Brussels sprouts , Beetroot , White and red cabbage, Carrots , Chard , Endive , Chicory , Kale , Kohlrabi , Leek , Lettuce (but not all types), Lamb's lettuce , Onions , Parsley , Parsnips , Radishes , Spring onion , Sorrel, Spinach and Turnip An easy way to protect your crops from frost is with fleece . You can find it on this site in a width of 2.4 meters and you can choose your own length. On our site you can order vegetable garden plants to replace your damaged plants. Some are dead ... no, that is not the motivation and reason for this article. Hopefully the frost will stay away and we can enjoy a carefree vegetable garden year 2017. Have fun with your vegetable garden! Tom