As frost approaches parts of Alberta, here’s what you need to harvest from your garden

As the final days of summer end this weekend and fall arrives, nighttime temperatures are low enough to destroy some of your hard-earned garden crops.

Environment Canada has issued frost warnings for parts of Alberta, including regions around Edmonton and Calgary.

Frost warnings are issued when temperatures below freezing are expected during the growing season, which could result in damage and destruction of plants and crops.

For many green thumbs, the risk of frost means covering up tomatoes at night. But sometimes even a blanket won’t protect your hard-earned harvest.

Here’s a basic list of what to harvest when temperatures drop to freezing and what you can save for the next few weeks.

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What to choose and bring inside

Tomatoes, peppers, peas, corn and gourds can be damaged by light frost.

Beans and peas: Ripe or not, beans and peas don’t tolerate frost. If you expect a hard frost tonight, pick them and enjoy.

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Corn: Mature corn will not tolerate frost and should be harvested immediately. Unripe cobs can be left on the stalk with the hope of another week of growth, but a good freeze will shorten their shelf life by three or four days.

Tomatoes and peppers: Ripe tomatoes or peppers should be picked immediately. If you have unripe tomatoes on the vine and the weather forecast is for temperatures around 0°C, you can take a chance. Try placing the plants along the south side of the house and covering them with a blanket. If the weather forecast is for -2°C or lower, it is better to pick unripe vegetables and let them ripen inside.

Gourds: Ripe squashes with thick skin should be picked immediately. Eat cucumbers right away. Cure pumpkins, squash, and zucchini in a cool, dark room on a surface other than metal or concrete—this will make them last longer. Unripe squash or squash won’t ripen off the vine, so you’ll want to leave them outside until their skins are fairly hard. Hope for the best, covering them with a blanket on those cold nights, and be careful not to crush the vine.

What to leave in the garden

Some vegetables can survive a light frost.

Apples: Many types of apples can remain on the tree until late September (assuming we don’t see a significant snowstorm in late September). A light frost can make the fruit sweeter and more flavorful.

Root vegetables: Vegetables like beets, carrots, onions, and potatoes can stay underground until the soil around them begins to freeze. A light frost wouldn’t be a problem, but any kind of frost that froze the ground around them would damage the goods.

Lettuce and lettuce: A light frost will change the structure of these items and they should be harvested to avoid freezing. But if we see a few more good weeks, the base of the plant may still be growing. If you are optimistic, try cutting off the useful greens and wait to see if you can get another growth before the end of the season.

Kale, cabbage and chard: These sturdy vegetables do well in light frost conditions. Their colors can become more vibrant and their flavors more pronounced. However, no garden plant can survive a deep freeze. If you think the temperature will drop significantly below 0°C at night, it would be best to harvest them and bring them inside.