When to Plant Head Lettuce in Colorado

Growing Head Lettuce in Colorado: Complete Guide

Head Lettuce (Lactuca sativa) is a crop that grows best when sown directly in the garden. Depending on your zone, the right time to direct sow in Colorado falls between March 13, 2027 (Zone 7a) and April 17, 2027 (Zone 4a), once soil temperatures are consistently warm enough for germination.

Because Colorado stretches across 7 USDA hardiness zones (4a, 4b, 5a, 5b, 6a, 6b, 7a), 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 70 days to maturity, Head Lettuce fits comfortably within Colorado's growing season in most zones. In the warmest parts of the state, a second planting later in the season may be possible.

Head Lettuce requires full sun and regular moisture. Mountain-state gardens contend with short seasons and intense UV at elevation — cold nights can persist well into June at higher altitudes.

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 Colorado.