April’s weather can be all over the place! In the space of a week, it can go from sunny and warm, to rainy and windy, to downright snowy and cold! What is a gardener to do? Be patient. And never plant all of your seeds at once! No matter how warm and sunny it gets, resist the urge to plant out your tender seedlings. Tomatoes, peppers, eggplants should not be planted out until Victoria Day.
The average last frost date for our area is May 11 according to OMAFRA (Ontario Ministry of Agriculture, Food & Rural Affairs). That means there is a 50% chance of having frost after that date. In May 2020, the temperature reached a low of minus 5 degrees C on the night of May 12, and a high of 35 on May 27. Yes, those are outliers, but those outliers are going to kill your plants! The big box stores often bring their plants out as early as possible, so people see tomato seedlings and petunias in the stores, or their neighbours’ window boxes, and worry that they’re late. Relax! Remember, the big box stores benefit if your plants die, because then you will go buy more! Save your money, and your seedlings. Climate change is making extreme weather more common, so we may be seeing more freak cold snaps in May, or a heatwave in April. Some people will wait until June 1 to plant peppers outside as they can get shocked by the cold, and stop growing. If we get a late frost, you can cover your plants, but they won’t survive a freeze. Any tender seedlings that were planted early last year, froze on May 12.
You can direct sow your frost-hardy crops such as lettuces, spinach, broccoli, cabbage, peas and kale now, either seeds or seedlings. The semi-frost-hardy crops such as beets, carrots, cauliflower or celery, can go in beginning to mid May. Tomatoes, beans, and other semi-frost-tender crops can go in by Victoria Day. Most people direct sow beans, but you’ll want tomato seedlings in our zone. Finally, frost-tender plants such as eggplant and pepper seedlings, as well as crops like pumpkins, squash, cucumbers, and melons are best left to the first of June. Many people put everything tender in by Victoria Day and cross their fingers!
Similarly, don’t put the tender flowers out until the tomatoes and peppers are out. Just like vegetables, some flowers will tolerate a little frost and cold, such as pansies, marigolds, geraniums, and the perennials that have made it through the winter, like iris. Other flowers, such as impatiens or begonias, will shrivel and die.
Don’t forget a good trellis for your pole beans, and if you have indeterminate tomato varieties, why not try trellising them? They will continue to grow up, as long as they have support.
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