The average last frost date, the date that marks the ‘safe to plant without any protection’ for tomatoes, peppers, squash, melons, and similar heat loving plants is technically the 15th of May. A look ahead at forecast shows no real threat of temperatures back down into the 30’s. Mid- to late May is by no means too late to start a vegetable garden – in fact, it is the ideal time to plant most of the summer staples.
Yes you can (and many do) plant earlier than this, but you take the risk of downturns in the weather slowing, stunting, or even killing your starts unless you protect them.
It’s also not too late to start many flowers. Amaranth, aster, black-eyed-Susan vine, broom, corn, cardinal climber, castor bean, celosia, coleus, cosmos, delphinium, dusty miller, four o’clock, foxglove, impatiens, lobelia, lupine, marigold, Mexican sunflower, morning glory, nasturtium, salvia, strawflower, sunflower, and zinnia are all plants that should be started right now – 1 to 2 weeks after average last frost date.