This one always takes me a minute. So mid-May should be the last for Toronto. Planted basil, marigold, frosted curls ornamental grass and Cherokee purple heirloom tomato today. Under light and on top of heat.  The marigold and tomato seeds were very few to a pack.  The grass is left over from at least three years so may not germinate. Did start a ginger root last week. The promise of spring.  In spite of the cool grey weather and zero temp.