Here in the northeast, mid spring teases us with periods of warm sunny days, tempting us to go out and buy the colorful annuals and tropical perennials stocked in local greenhouses. We forget that we may well get several more chilly nights. Perhaps frost is unlikely, but the soil temperature is going to remain too cold for the heat lovers until nights stay above 55 degrees F. If you plant these warm weather gems too soon, you will most assuredly stunt their growth.
The old timers always said to wait until Memorial Day to plant tomatoes and annuals, and for good reason. Only last year, many of us experienced a cool wet June, and many a northern gardener lamented how poorly Coleus, Colocasia and Cannas performed.