When to Plant Annuals Outdoors: Long Island Timing and Seedling Science

For Long Island gardeners (and similar climates), the window for moving annuals outdoors is open. Here's why now works and what to watch for.

The Nursery Timeline

Garden center annuals were started months ago in greenhouses—timing is everything in the nursery business. By the time you buy them, they're hardened off and ready for the garden.

Why Spring Conditions Are Ideal

• Frost-free: Safe for tender annuals
• Optimal temperatures: Low to mid-70s°F maximize chlorophyll efficiency in C3 plants (petunias, begonias, impatiens, roses)
• Cool nights: Reduce respiration losses, promoting stronger growth

The Real Threat: Slugs, Not Weather

At this time of year, slugs pose the biggest danger to young transplants. Scout evenings with a flashlight, use copper tape barriers, or apply diatomaceous earth around vulnerable plants.

Plant confidently now—your annuals will establish quickly in these perfect spring conditions.