Planting Time

Warm season and cool season crops are terms used to describe the optimal temperature range

Some gardeners like to start all of their new plants by seed in the later winter and then harden them off and transplant them outside when the soil warms up in the spring. If you are starting seeds indoors, find our guide online at www.harrowsmithmag.com/startseedsindoors.

Others will find all of their plants at the market or nursery and get growing the same day. Whichever way you start, it’s important to start off with the following key tips.

Warm Season and Cool Season Crops

Warm season and cool season crops are terms used to describe the optimal temperature range for growing different types of plants. Many Canadians wait until the long May weekend to start planting; however, this
is not necessary as many food plants thrive in the cooler temperatures of April and early May. We sow our carrots the second week of May in our zone 5 gardens. Onions, lettuce, beets, and peas will germinate and grow when sown late in April, in most Canadian gardens.

Some plants are tolerant of light frost and will grow well when planted out in late April or early May. These include

  • all the brassica family
    • cauliflower,
    • broccoli,
    • cabbage,
    • kale etc.
  • Swiss chard.

Other crops should be left until the soil warms to about 18oC and the risk of frost has passed which may be early June in many parts of Canada.

These “warm season” crops include

  • tomatoes,
  • peppers,
  • corn, and
  • squash (winter and summer).

These crops are typically harvested in the summer or early fall.

The Harrowsmith Team

Harrowsmith is the farm-to-condo go-to for living sustainably and simply. Our mission is to offer a down-to-earth Canadian perspective on topics of gardening, home and design, travel and culture, food, health, wellness and the environment.

Posted on Monday, April 29th, 2024

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