Delaware in USDA Zone 7
Delaware is primarily in Zone 7. Local microclimates can vary.
Growing Lettuce & Salad Greens in Delaware
Zone 7 gardeners hit the sweet spot for growing exceptional lettuce and salad greens. With an average last frost around April 1st and first frost near October 30th, you've got roughly 210 days to work with – plenty of time for multiple plantings and succession crops. The moderate climate means you can grow both cool-season favorites and heat-tolerant varieties, though the summer months will test even the most bolt-resistant lettuces.
The key to success in Zone 7 is choosing varieties that can handle the transition seasons well. Spring brings unpredictable temperature swings, while summer heat can quickly turn tender greens bitter. Look for bolt-resistant varieties for late spring plantings and heat-tolerant options for summer growing. Cold-hardy types will extend your harvest well into fall and even winter with minimal protection.
Our top picks for Zone 7 include reliable performers like Buttercrunch and Black Seeded Simpson for spring, heat-tolerant Salanova varieties for summer succession, and cold-hardy options like Mâche and winter-hardy Romaine types for fall and winter harvests. These varieties have proven themselves in Zone 7's unique climate challenges.
Zone 7 Lettuce & Salad Greens for Delaware
110 varieties · Last frost April 1 · 210-day season
Zone 7 Growing Tips for Delaware
Start your lettuce growing journey indoors 4-6 weeks before your last frost date – that puts seed starting around mid-February to early March. You can direct seed hardy varieties like arugula and spinach as early as 2-3 weeks before the last frost, but wait until soil temperatures reach 45°F consistently. For transplants, harden them off and plant outside 2-3 weeks before the last frost date, using row covers if temperatures dip below 28°F.
Summer growing requires strategy in Zone 7. Start seeds indoors during hot weather and transplant in late afternoon or on cloudy days. Provide afternoon shade using shade cloth (30-50%) or plant in naturally shadier spots. Focus on heat-tolerant varieties like New Red Fire, Salanova types, and Batavia lettuces during June through August. Stop summer plantings by early August to avoid the worst heat stress.
For fall and winter harvests, start seeds in late July through September. These plantings often outperform spring crops because they mature in cooling weather. Use row covers, cold frames, or low tunnels to extend harvests through December and beyond. Varieties like Mâche, Winter Density Romaine, and cold-hardy leaf lettuces can survive Zone 7 winters with minimal protection, giving you fresh greens when store-bought options are expensive and lackluster.