When to Start Your Summer Annuals in B.C.

Just how warm does it need to be to plant in B.C.?

Q: How warm should it be before I plant my annuals? I live in Vancouver B.C.

That depends on the annuals. So-called half-hardy annuals, like snapdragons and sweet peas, can take cool temperatures. Others, like marigolds, petunias, begonias and impatiens, like more warmth. The general rule of thumb, to be safe for most annuals, is Victoria Day weekend, at the end of May.

The problem with planting sooner is not only the air temperatures at night, but the temperature of the soil. If annuals are planted in the open ground and it gets cold and rainy, they have to “sit” in cold, sodden soil. This can cause their growth to halt or worse—their roots can get fungal diseases and rot.

I cheat by keeping a few annuals in containers under an overhang that gets afternoon sun. My geranium has been outside for a month now, but it doesn’t get inundated with cold rain due to the balcony above it. In addition, if the night is clear and cold, I throw a layer of floating row cover over it. (Well, to be honest, I throw a gauzy lace curtain over it, ’cause that’s what I have on hand!). It looks very healthy.