When to Plant Zinnia in Delaware

Growing Zinnia in Delaware: Complete Guide

Zinnia (Zinnia elegans) is a crop that grows best when sown directly in the garden. In Delaware, the right time to direct sow is around Sunday, April 12, 2026, once soil temperatures are consistently warm enough for germination.

Because Delaware stretches across 3 USDA hardiness zones (7a, 7b, 8a), planting windows can shift by as much as two to four weeks from one end of the state to the other. Gardeners in the warmer southern zones can start earlier, while those in cooler northern zones should wait until the zone table above shows their last frost has passed.

With 60 days to maturity, Zinnia fits comfortably within Delaware's growing season in most zones. In the warmest parts of the state, a second planting later in the season may be possible.

Zinnia requires full sun (6-8 hours) and moderate (1 inch/week) moisture. Mid-Atlantic summers bring heat and humidity — ensure good air circulation and watch for fungal issues like powdery mildew.

For the most precise planting dates tailored to your exact location, enter your ZIP code on our planting calendar or use the zone table above to find the schedule for your area of Delaware.