When to Plant Sunflower in Unknown

Growing Sunflower in Unknown: Complete Guide

Sunflower (Helianthus annuus) is a crop that grows best when sown directly in the garden. Depending on your zone, the right time to direct sow in Unknown falls between February 17, 2027 (Zone 9b) and May 17, 2027 (Zone 5a), once soil temperatures are consistently warm enough for germination.

Because Unknown stretches across 6 USDA hardiness zones (5a, 7a, 7b, 8b, 9a, 9b), planting windows can shift by as much as six to eight 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 80 days to maturity, Sunflower fits comfortably within Unknown's growing season in most zones. In the warmest parts of the state, a second planting later in the season may be possible.

Sunflower requires full sun (6-8 hours) and low-moderate (1 inch/week) moisture. Check your local forecast for humidity and heat advisories that may affect timing and pest pressure.

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 Unknown.