Threat of frost, may need to cover plants tonight

With a threat of frost in the forecast for tonight, you may want to cover any flowers or vegetables you have already planted.

Environment Canada is calling for a low of -3 degrees overnight.

Dorinda Penner, owner of Sunshine Greenhouse just outside of Steinbach, says at that temperature you will want to either bring plants indoors or cover them. If you choose the latter, Penner suggests using a lightweight blanket, so as not to damage any young plants. Another option is to set your alarm early and then go out and hose down your plants with water.

Frost in late May is nothing new for southern Manitoba. And, even though Penner says she likes to wait until June to put in her garden, she refuses to scold those eager gardeners who have already planted.

"We've had seasons where people plant early in May and you can have great success," she says. "You just have to be vigilant and listen to the weather and if you need to cover, you cover."

One thing to keep in mind for tonight is the wind. The wind is supposed to die right down to only about four or five kilometres per hour overnight. That is different from last night, when even though the air was not as cold, the wind kept any potential frost from doing any damage.

"On our property here at Sunshine yesterday, we didn't have any frost," says Penner. "The temps I don't think quite dropped that low but the wind was in our favour, so then it doesn't grab."

At -3 degrees, Penner says she would not worry about any damage to perennials that are starting to come up in your garden. She says at that temperature, they might not even lose tip growth. However, if those are new perennials that you just purchased from a greenhouse and planted this year, Penner says those are items you will want to protect. Penner notes she would also not be concerned about fruit trees.

"I'm not worried about losing the blossoms, losing all the fruit at that -3," she says. "If we jump down colder than that, there may be some concern."

According to Penner, not all vegetables dislike freezing temperatures. For example, cabbage, broccoli, cauliflower and onions do not mind temperatures of -1 or -2. For vegetables that have been seeded in your garden, Penner says those should also be okay. But, tender plants like peppers and tomatoes should be covered. Also, with cucumber plants, Penner says those can start to go limp even before there is frost.

As for flowers, Penner says petunias should be okay at -3, though she would be cautious with zinnias, dahlias and salvias.

For those who have not yet planted their garden, or those unfortunate enough to lose some plants to frost this week, Penner says they still have a lot to choose from at their greenhouse. With COVID-19 sparking new interest in gardening in the southeast last year, Penner says she grew a lot more this year and have a good supply yet for all those still looking.