Regional guide

Delaware Frost-Probability Vegetable Garden

University of Delaware Cooperative Extension guide for frost-probability planning, succession rows, fall crops, and tender-crop timing in Delaware.

Climate signals

• The University of Delaware Cooperative Extension source says recommended planting dates are based on projected last frost, with frost defined as a day reaching 35 F or lower.
• Its rule of thumb is to plant tender plants such as tomatoes and peppers two weeks after the 10 percent probability of another frost date.
• The source lists a 10 percent probability date of April 26 for Wilmington, says the UD farm at Newark lists April 20, and notes other resources list dates as late as May 7.
• The recommendation is to use April 26, which moves the earliest tender planting date to May 10.
• The guide frames Delaware garden planning around a continuous supply from early spring to late fall, not a single spring planting.

Planning notes

• Plan late vegetables to follow early ones and include succession crops, a fall garden, small fruits, and overwintered crops where space allows.
• The source says spinach planted in fall can live over winter and be picked in early spring.
• Rotate crops so similar vegetables are not planted in the same location consecutively when space allows.
• For spring peas, the suggested plan lists March 15 to April 1 and April 10 to April 30 planting windows.
• For spring lettuce, it lists April 1 to April 15 and April 15 to April 30 planting windows.
• For carrots, it lists April 1 to April 30, May 1 to May 15, and a late July 10 to August 15 window.
• For bush beans, it lists May 5 to May 15, May 20 to May 30, and a late July 25 to August 15 window.
• For tomatoes, peppers, and eggplant, the suggested plan uses May 10 to May 30 planting windows.
• For fall greens, the suggested plan includes spinach from August 15 to September 10 and lettuce from July 15 to September 1.
• For sweet corn, it lists May 1 to May 15 and May 20 to June 5 plantings before later succession rows.
• The source labels harvest ranges as typical harvest periods that may vary with specific varieties and local weather.
• The source's suggested varieties include Provider beans, Detroit Dark Red beets, Marketmore 76 cucumbers, California Wonder peppers, Sugar Snap peas, Bloomsdale spinach, and Sugar Baby watermelon.
• Use these priority catalog links as Delaware crop-row and variety-list examples where applicable, not as a complete local variety list.

Catalog crop examples

These catalog entries match crops covered by the regional timing source; variety-specific details remain tied to each seed entry's own source.

• Provider Bush Bean Vegetable · Warm · 50 days
• Detroit Dark Red Beet Vegetable · Cool · 58 days
• Waltham 29 Broccoli Vegetable · Cool · 74 days
• Long Island Improved Brussels Sprouts Vegetable · Cool · 100 days
• Golden Acre Cabbage Vegetable · Cool · 64 days
• Snowball Y Cauliflower Vegetable · Cool · 70 days
• Danvers 126 Carrot Vegetable · Shoulder · 70 days
• Bright Lights Swiss Chard Vegetable · Shoulder · 55 days
• Golden Bantam Sweet Corn Vegetable · Warm · 80 days
• Marketmore 76 Cucumber Vegetable · Warm · 58 days
• Black Beauty Eggplant Vegetable · Warm · 80 days
• Lacinato Kale Vegetable · Cool · 60 days
• Early White Vienna Kohlrabi Vegetable · Cool · 55 days
• Black Seeded Simpson Lettuce Vegetable · Cool · 45 days
• Southern Giant Curled Mustard Vegetable · Cool · 45 days
• Evergreen Bunching Onion Vegetable · Shoulder · 65 days
• Sugar Snap Pea Vegetable · Cool · 62 days
• California Wonder Pepper Vegetable · Warm · 72 days
• Small Sugar Pumpkin Vegetable · Warm · 100 days
• French Breakfast Radish Vegetable · Cool · 28 days
• Bloomsdale Spinach Vegetable · Cool · 42 days
• Waltham Butternut Squash Vegetable · Warm · 95 days
• Roma Tomato Vegetable · Warm · 76 days
• Purple Top White Globe Turnip Vegetable · Cool · 55 days
• Sugar Baby Watermelon Vegetable · Warm · 80 days

Related regional guides

• New Jersey Frost-Range Seed-Starting Garden Rutgers NJAES seed-starting guide for New Jersey gardeners using local last-frost ranges, cool-season transplants, and warm-season soil readiness.
• Central Maryland Planting Calendar Vegetable Garden A UMD Extension Central Maryland planting-calendar guide for frost assumptions, warm-soil crops, successions, transplants, and crop windows.
• Virginia Hardiness Zone Vegetable Planting Guide A Virginia Cooperative Extension guide for USDA hardiness-zone vegetable planting tables, frost ranges, microclimates, row covers, and crop windows.

Source: University of Delaware Cooperative Extension Planning a Vegetable Garden