Every spring, gardeners are eager to get their hands dirty working in their flower and vegetable beds. Veteran gardeners know from experience that there is a proper time to plant certain vegetables and flowers. Novice gardeners may be fooled by unseasonably warm, sunny days into thinking it’s fine to plant tender annual flowers and warm-season vegetables, only to be dismayed when a late frost mercilessly kills their begonias and tomatoes. Some annual flowers, such as pansies, snapdragons, and stocks, are safe to plant or pot early for cheery spring color. Cool-weather vegetables, including onions,
peas, spinach, and cabbage can be planted in cold, wet soil as transplants or seeds and will thrive, as will potato tubers, easily surviving late frosts.
In Central Indiana, it is extremely rare to have a “killing frost/freeze” after the middle of
April. However, light frosts are not unusual well into May. Conventional gardening
wisdom says to not plant any “tender” flower or vegetable seeds or transplants until
after Mother's Day weekend. Not only is the chance of cold weather remote after that
weekend, but soil has had a chance to warm up, which is equally important for the
health and vitality of warm-season plants. Planting a tomato transplant or sowing zinnia
seeds in cold soil can result in delayed growth or even rotten roots or seeds.
I’m reminded what the late Wayne Cox, of the locally famous Cox’s Plant Farm told
me years ago. Cox’s sows and sells many thousands of flowers and vegetable plants
every year. Shoppers flocking to the sprawling grounds and greenhouse complex in early May will find for sale large, potted tomato plants in flower, some even with ripening tomatoes. Although the staff warms customers to not plant these tomatoes in the ground until after Mother's Day, many customers sheepishly return to buy replacement plants after getting fooled by a few unseasonably warm days to plant their tomato plants, only to lose them to a late frost. Resist that temptation, and you won’t be setting yourself up for disappointment. Wait a few more weeks, then plant to your heart’s content.