When to Safely Plant Annual Flowers in Your Garden

Determine the frost-free date for your area from your local cooperative extension office, a garden center, or an experienced gardener. Use this date as a guideline based on the cold tolerance of your chosen flowers. Cool-season annuals like pansies, snapdragons, and pot marigolds can be set out several weeks before the last frost. Tropicals extremely sensitive to cold, such as impatiens and Thai basil, should wait until a couple of weeks after the frost-free date.

Keep an eye on the weather; some years warm up earlier than others. Be prepared to cover plants if an unseasonably late frost threatens. Remember that soil temperature matters too—annuals grow best when the soil has warmed. Raised beds warm faster than in-ground beds, allowing earlier planting.