The weather guys at City-TV warn there might be frost tonight in the GTA — though the closer you are to the moderating effect of the lake, the lower the risk. (FYI, The Weather Network doesn’t put frost on the horizon.)
Spring/fall frost dates are merely based on statistics, and freak weather does happen. Think of that hailstorm coming out of nowhere on Saturday. I was out walking when it hit, and have many polka-dot bruises to prove it. Keep an ear and eye open for weather warnings at this time of year. Even the chance of frost is just the chance of frost given a certain set of weather conditions. There are no guarantees either way. However, people buy lottery tickets with a far greater chance of losing.
The link to City above gives tips on what you can do. These include my favourite, super-easy technique, which is to tent newspapers over your plants overnight to protect them. An overturned bucket can work just as well. Remove them in the morning when the soil warms up.
At risk are tender annuals or the tender perennials we usually treat as annuals in Canada, such as the coleus I chose for my planter. Garden-grown hardy perennials should be fine — but if you’ve just planted some whose growth has been accelerated in the warmth of a greenhouse, they might want a little extra attention.
My new ‘Juicy Lucy’ coleus (Solenostemon ‘Juicy Lucy’) has already been nipped by cool overnight temps, because I foolishly left her in an exposed position without hardening off. So for this evening, I’ll take precautions, just in case, and will bring her indoors for a sleepover.