Frost in the vegetable garden... Which vegetables, why and what now?

Frost in the vegetable garden. We're not talking about Willem-Alexander or Filip here. These two monarchs are leaving our vegetables alone (for now). We are indeed talking about temperatures below freezing. Two days ago, I myself fell victim to frost in the vegetable garden with two crops. Under the thermometer shelter, it measured -3.3°C. I had already moved all my peppers , bell peppers , zucchini , basil, and all other vegetables into the garage. There, they are protected. But as an impatient vegetable gardener, I had also planted two bell pepper plants in the open ground in the greenhouse . A red and a yellow bell pepper from Moestuinweetjes. The yellow one is badly damaged and will probably have to be replaced by one still in pots. The red one is useless. The yellow one was also a bit closer to the window, maybe that's why? And when I looked at my potato field this morning, I saw that the 5- to 10-cm-high foliage of my Frieslander potatoes was completely limp and had suffered greatly from the frost in the vegetable garden. Fortunately, I saw encouraging comments in the Facebook Ebook Group Vegetable Garden. My colleague Peter, "Plukkers," also reassured me in his Limburgish way: "They'll get there." No big deal, but with some fleece, I still had a cheerful yellow pepper plant and 7 meters of cheerful Frieslanders . It's not even May 15th (Ice Saints Day) yet, so just to be sure, I looked up some information about frost resistance of crops and tools.

My yellow (left) and red bell pepper .

In early spring, you really need to keep an eye on the weather. I check Weeronline.nl's 2-, 5-, and 14-day forecasts for my region. You can enter your own municipality or city, and you can accurately estimate when to sound the frost alarm. Is this site 100% reliable? I'm afraid not. The day before yesterday (when my pepper plant and the Frieslanders came under fire) the site predicted -2°C, but it actually ended up being -3.3°C. It wasn't that far off. Even at the end of autumn, you need to keep a close eye on this site, or the frost in your vegetable garden will eat away at the last of your vegetables.

Weather forecast in my area

Frost resistance is a plant's ability to survive temperatures below 0°C without damage. When air cools, dew forms on all exposed surfaces. When the air is below 0°C, ice crystals form. A light frost between 0°C and -2°C is considered a hard frost, while a frost below -4°C is very dangerous for most vegetables.

Frost damage occurs when the water in the plant cells expands. Everyone's experienced it before. A bottle of water or wine is left in the freezer, and boom! It's more or less the same with vegetables. But that doesn't explain why some plants are more frost-resistant than others. The reason lies in the composition of the water stored in the plant cells. Vegetables that thrive in cold or frosty conditions are those that naturally produce a lot of sugars. That sugar is also present in the moisture of the plant cells. Sugar water freezes at much lower temperatures than regular water. And that's why my bell 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 burst of sugar when it gets too cold. And that sugar makes the vegetables tastier.

Besides sugar, smaller, shorter varieties can benefit more from the heat the soil stores 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. Moisture retains heat and insulates the air. That's why clear nights are also the coldest. You can buy seeds for all vegetables that are better suited to cold temperatures. You have the Meikonigin for lettuce, the Berlikum for carrots , the Walcheren cauliflower , etc. These are varieties that meet the above criteria (produce sugar, shorter varieties, etc.).

Frost-tolerant crops can easily be replanted after harvest, covered with some soil. Think of beetroot , carrots , leeks , radishes, or parsnips . You can dig them up when you need them. Just be careful, though, as the weather warms up, they'll sprout again and lose their flavor.