May Vegetable Growing Calendar For Canadian Hardiness zones 4 and 5
The average date of the last spring frost in eastern Ontario is May 11. As the soil grows warmer, sow annual seeds like beets, carrots, lettuce, late potatoes, and chard directly in the soil. Transplants of cauliflower can be put in.
Begin to harden off indoor grown seedlings by transferring them outdoors to a protected area or cold frame. If purchasing seedlings, make sure they are acclimatized to the outdoors before planting. After the Victoria Day weekend, you can plant seedlings of warm season vegetables, such as tomatoes, peppers, tomatillos, eggplants, cucumbers, watermelons, and melons.
Corn and beans can be direct seeded. Plant squash, field cucumbers, and pumpkins by seed or transplants.
Thin seedlings that are growing too thickly. Water well after planting. Set up supports ahead of time for tall crops.