When is it okay to start a garden in our area? Veggies like tomatoes, onions, and sweetcorn? I did over hear this question while I was shopping at a nursery last weekend…..I had no good clue. The garden center specialist said “Don’t put out tomatoes or other tender plants before Memorial Day, mother nature can play some cold, cruel tricks on gardens planted too early”. You ought to be okay planting corn and onions in mid-May. They’ll tolerate more cold than tomatoes or peppers. Who said you can’t learn something while shopping and ease dropping!