DENVER — People are buying plants like crazy. Is it safe to plant them outside?
In the past, annuals were categorized as hardy, half-hardy and tender. Hardy annuals can withstand a frost. These include pansies, peas, kale and cabbage. Half-hardy annuals can withstand cool night temperatures almost down to freezing. These include petunias, verbena, calendula, stock, snapdragons, lettuce, spinach, broccoli and chard.
Tender annuals do best in the warm season and shouldn’t be planted until night temperatures stay reliably above 50 degrees. These include tomatoes, peppers, squash, peppers, basil, geraniums, marigolds, zinnias, impatiens and sweet potato vines…