What to plant in March in Delaware
In Delaware (DE), March sits about 4 weeks before the average last frost (April 14). The state averages 191 frost-free days a year (last frost April 14, first frost October 22; USDA zones 7a, 7b).
68 crops have a sowing or planting window this month, including mache (corn salad), pea, spinach, green onion / scallion, arugula, beet - and 11 of those windows close during March.
Dates here come from Delaware frost dates (last frost Apr 14, first frost Oct 22). For one crop in detail, see when to plant pea, spinach or arugula in Delaware.
Delaware: planting activity through the year
Last chance in March
Ground Cherry (start seeds indoors, by Mar 3) · Lemon Balm (start seeds indoors, by Mar 3) · Shiso (Perilla) (start seeds indoors, by Mar 3) · Sweet Marjoram (start seeds indoors, by Mar 3) · Tomatillo (start seeds indoors, by Mar 3) · Tomato (start seeds indoors, by Mar 3) · Broccoli (start seeds indoors, by Mar 10) · Brussels Sprouts (start seeds indoors, by Mar 10) · Cabbage (start seeds indoors, by Mar 10) · Cauliflower (start seeds indoors, by Mar 10) · Kale (start seeds indoors, by Mar 10)
Sow or plant outdoors in March (61)
Direct sowing and transplanting windows that fall in March, most urgent first. Windows are one-to-two-week bands around the ideal date.
| Crop | What to do | Window | This month |
|---|---|---|---|
| Mache (Corn Salad) | Direct sow (spring) | Mar 5 – Mar 24 | Mar 5 – Mar 24 |
| Pea | Direct sow (spring) | Mar 5 – Mar 24 | Mar 5 – Mar 24 |
| Spinach | Direct sow (spring) | Mar 5 – Mar 24 | Mar 5 – Mar 24 |
| Green Onion / Scallion | Transplant outdoors | Mar 10 – Mar 27 | Mar 10 – Mar 27 |
| Arugula | Direct sow (spring) | Mar 12 – Mar 31 | Mar 12 – Mar 31 |
| Beet | Direct sow (spring) | Mar 12 – Mar 31 | Mar 12 – Mar 31 |
| Fava Bean (Broad Bean) | Direct sow (spring) | Mar 12 – Mar 31 | Mar 12 – Mar 31 |
| Green Onion / Scallion | Direct sow (spring) | Mar 12 – Mar 31 | Mar 12 – Mar 31 |
| Mizuna | Direct sow (spring) | Mar 12 – Mar 31 | Mar 12 – Mar 31 |
| Onion | Direct sow (spring) | Mar 12 – Mar 31 | Mar 12 – Mar 31 |
| Radish | Direct sow (spring) | Mar 12 – Mar 31 | Mar 12 – Mar 31 |
| Shallot | Direct sow (spring) | Mar 12 – Mar 31 | Mar 12 – Mar 31 |
| Tatsoi | Direct sow (spring) | Mar 12 – Mar 31 | Mar 12 – Mar 31 |
| Cabbage | Transplant outdoors | Mar 17 – Apr 3 | Opens Mar 17 |
| Collard Greens | Transplant outdoors | Mar 17 – Apr 3 | Opens Mar 17 |
| Horseradish | Plant crowns / divisions | Mar 17 – Apr 3 | Opens Mar 17 |
| Kale | Transplant outdoors | Mar 17 – Apr 3 | Opens Mar 17 |
| Kohlrabi | Transplant outdoors | Mar 17 – Apr 3 | Opens Mar 17 |
| Onion | Transplant outdoors | Mar 17 – Apr 3 | Opens Mar 17 |
| Rhubarb | Plant crowns / divisions | Mar 17 – Apr 3 | Opens Mar 17 |
| Shallot | Transplant outdoors | Mar 17 – Apr 3 | Opens Mar 17 |
| Carrot | Direct sow (spring) | Mar 19 – Apr 7 | Opens Mar 19 |
| Chervil | Direct sow (spring) | Mar 19 – Apr 7 | Opens Mar 19 |
| Endive & Escarole | Direct sow (spring) | Mar 19 – Apr 7 | Opens Mar 19 |
| Kohlrabi | Direct sow (spring) | Mar 19 – Apr 7 | Opens Mar 19 |
| Lettuce | Direct sow (spring) | Mar 19 – Apr 7 | Opens Mar 19 |
| Mustard Greens | Direct sow (spring) | Mar 19 – Apr 7 | Opens Mar 19 |
| Rapini (Broccoli Raab) | Direct sow (spring) | Mar 19 – Apr 7 | Opens Mar 19 |
| Turnip | Direct sow (spring) | Mar 19 – Apr 7 | Opens Mar 19 |
| Watercress | Direct sow (spring) | Mar 19 – Apr 7 | Opens Mar 19 |
| Asparagus | Plant crowns / divisions | Mar 24 – Apr 10 | Opens Mar 24 |
| Bok Choy / Pak Choi | Transplant outdoors | Mar 24 – Apr 10 | Opens Mar 24 |
| Broccoli | Transplant outdoors | Mar 24 – Apr 10 | Opens Mar 24 |
| Brussels Sprouts | Transplant outdoors | Mar 24 – Apr 10 | Opens Mar 24 |
| Cauliflower | Transplant outdoors | Mar 24 – Apr 10 | Opens Mar 24 |
| Chives | Plant crowns / divisions | Mar 24 – Apr 10 | Opens Mar 24 |
| Endive & Escarole | Transplant outdoors | Mar 24 – Apr 10 | Opens Mar 24 |
| Leek | Transplant outdoors | Mar 24 – Apr 10 | Opens Mar 24 |
| Lettuce | Transplant outdoors | Mar 24 – Apr 10 | Opens Mar 24 |
| Napa Cabbage | Transplant outdoors | Mar 24 – Apr 10 | Opens Mar 24 |
| Parsley | Transplant outdoors | Mar 24 – Apr 10 | Opens Mar 24 |
| Radicchio | Transplant outdoors | Mar 24 – Apr 10 | Opens Mar 24 |
| Sorrel | Plant crowns / divisions | Mar 24 – Apr 10 | Opens Mar 24 |
| Swiss Chard | Transplant outdoors | Mar 24 – Apr 10 | Opens Mar 24 |
| Watercress | Transplant outdoors | Mar 24 – Apr 10 | Opens Mar 24 |
| Bok Choy / Pak Choi | Direct sow (spring) | Mar 26 – Apr 14 | Opens Mar 26 |
| Borage | Direct sow (spring) | Mar 26 – Apr 14 | Opens Mar 26 |
| Cilantro / Coriander | Direct sow (spring) | Mar 26 – Apr 14 | Opens Mar 26 |
| Collard Greens | Direct sow (spring) | Mar 26 – Apr 14 | Opens Mar 26 |
| Kale | Direct sow (spring) | Mar 26 – Apr 14 | Opens Mar 26 |
| Leek | Direct sow (spring) | Mar 26 – Apr 14 | Opens Mar 26 |
| Napa Cabbage | Direct sow (spring) | Mar 26 – Apr 14 | Opens Mar 26 |
| Parsley | Direct sow (spring) | Mar 26 – Apr 14 | Opens Mar 26 |
| Potato | Direct sow (spring) | Mar 26 – Apr 14 | Opens Mar 26 |
| Radicchio | Direct sow (spring) | Mar 26 – Apr 14 | Opens Mar 26 |
| Salsify | Direct sow (spring) | Mar 26 – Apr 14 | Opens Mar 26 |
| Fennel (Bulb) | Transplant outdoors | Mar 31 – Apr 17 | Opens Mar 31 |
| Globe Artichoke | Plant crowns / divisions | Mar 31 – Apr 17 | Opens Mar 31 |
| Lemon Balm | Transplant outdoors | Mar 31 – Apr 17 | Opens Mar 31 |
| Mint | Transplant outdoors | Mar 31 – Apr 17 | Opens Mar 31 |
| Tarragon | Transplant outdoors | Mar 31 – Apr 17 | Opens Mar 31 |
Start seeds indoors in March (37)
Indoor sowings for transplants later. Six to eight weeks under lights is typical for tomatoes and peppers; onions and leeks need longer.
| Crop | What to do | Window | This month |
|---|---|---|---|
| Ground Cherry | Start seeds indoors | Feb 17 – Mar 3 | Last chance - ends Mar 3 |
| Lemon Balm | Start seeds indoors | Feb 17 – Mar 3 | Last chance - ends Mar 3 |
| Shiso (Perilla) | Start seeds indoors | Feb 17 – Mar 3 | Last chance - ends Mar 3 |
| Sweet Marjoram | Start seeds indoors | Feb 17 – Mar 3 | Last chance - ends Mar 3 |
| Tomatillo | Start seeds indoors | Feb 17 – Mar 3 | Last chance - ends Mar 3 |
| Tomato | Start seeds indoors | Feb 17 – Mar 3 | Last chance - ends Mar 3 |
| Broccoli | Start seeds indoors | Feb 24 – Mar 10 | Last chance - ends Mar 10 |
| Brussels Sprouts | Start seeds indoors | Feb 24 – Mar 10 | Last chance - ends Mar 10 |
| Cabbage | Start seeds indoors | Feb 24 – Mar 10 | Last chance - ends Mar 10 |
| Cauliflower | Start seeds indoors | Feb 24 – Mar 10 | Last chance - ends Mar 10 |
| Kale | Start seeds indoors | Feb 24 – Mar 10 | Last chance - ends Mar 10 |
| Basil | Start seeds indoors | Mar 3 – Mar 17 | Mar 3 – Mar 17 |
| Collard Greens | Start seeds indoors | Mar 3 – Mar 17 | Mar 3 – Mar 17 |
| Endive & Escarole | Start seeds indoors | Mar 3 – Mar 17 | Mar 3 – Mar 17 |
| Kohlrabi | Start seeds indoors | Mar 3 – Mar 17 | Mar 3 – Mar 17 |
| Malabar Spinach | Start seeds indoors | Mar 3 – Mar 17 | Mar 3 – Mar 17 |
| Okra | Start seeds indoors | Mar 3 – Mar 17 | Mar 3 – Mar 17 |
| Radicchio | Start seeds indoors | Mar 3 – Mar 17 | Mar 3 – Mar 17 |
| Summer Savory | Start seeds indoors | Mar 3 – Mar 17 | Mar 3 – Mar 17 |
| Bitter Melon | Start seeds indoors | Mar 10 – Mar 24 | Mar 10 – Mar 24 |
| Bok Choy / Pak Choi | Start seeds indoors | Mar 10 – Mar 24 | Mar 10 – Mar 24 |
| Cucamelon | Start seeds indoors | Mar 10 – Mar 24 | Mar 10 – Mar 24 |
| Fennel (Bulb) | Start seeds indoors | Mar 10 – Mar 24 | Mar 10 – Mar 24 |
| Lettuce | Start seeds indoors | Mar 10 – Mar 24 | Mar 10 – Mar 24 |
| Luffa (Loofah Gourd) | Start seeds indoors | Mar 10 – Mar 24 | Mar 10 – Mar 24 |
| Napa Cabbage | Start seeds indoors | Mar 10 – Mar 24 | Mar 10 – Mar 24 |
| New Zealand Spinach | Start seeds indoors | Mar 10 – Mar 24 | Mar 10 – Mar 24 |
| Peanut | Start seeds indoors | Mar 10 – Mar 24 | Mar 10 – Mar 24 |
| Swiss Chard | Start seeds indoors | Mar 10 – Mar 24 | Mar 10 – Mar 24 |
| Watercress | Start seeds indoors | Mar 10 – Mar 24 | Mar 10 – Mar 24 |
| Cantaloupe / Muskmelon | Start seeds indoors | Mar 17 – Mar 31 | Mar 17 – Mar 31 |
| Cucumber | Start seeds indoors | Mar 17 – Mar 31 | Mar 17 – Mar 31 |
| Pumpkin | Start seeds indoors | Mar 17 – Mar 31 | Mar 17 – Mar 31 |
| Sunflower | Start seeds indoors | Mar 17 – Mar 31 | Mar 17 – Mar 31 |
| Watermelon | Start seeds indoors | Mar 17 – Mar 31 | Mar 17 – Mar 31 |
| Winter Squash | Start seeds indoors | Mar 17 – Mar 31 | Mar 17 – Mar 31 |
| Zucchini / Summer Squash | Start seeds indoors | Mar 17 – Mar 31 | Mar 17 – Mar 31 |
Planting dates for popular crops in Delaware
Every crop has its own full-year dates for Delaware: indoor start, transplant or direct sowing, and harvest.
Seed-starting season: March garden jobs in Delaware
- Start 37 crops indoors this month, including ground cherry, lemon balm, shiso (perilla), sweet marjoram. Use a sterile mix and good light - see starting seeds indoors.
- 4 weeks until the average last frost (April 14). The seed-starting calculator works out each crop's exact sowing date from it.
- Keep seedlings from stretching: lights 2-3 inches above the leaves for 14-16 hours a day, and a fan or a daily brush of the hand across the tops.
- Prepare beds as soon as the soil crumbles instead of smearing when squeezed - working wet soil ruins its structure for the season.
Questions gardeners ask
What vegetables can I plant in Delaware in March?
68 crops have a window in March: mache (corn salad), pea, spinach, green onion / scallion, arugula, beet, fava bean (broad bean), mizuna, onion, radish and more. The tables above give the exact dates for each.
Is it too late to plant tomatoes in Delaware in March?
No - start seeds indoors runs Feb 17 – Mar 3 in Delaware, so do it before March 3.
Is it too late to plant lettuce in Delaware in March?
No - start seeds indoors runs Mar 10 – Mar 24 in Delaware, so do it before March 24.
When is the first frost in Delaware?
The statewide average first fall frost is around October 22 and the last spring frost around April 14. Your town can be a week or two either side - look yours up by ZIP code.
What should I start indoors in March in Delaware?
Ground Cherry (Feb 17 – Mar 3), Lemon Balm (Feb 17 – Mar 3), Shiso (Perilla) (Feb 17 – Mar 3), Sweet Marjoram (Feb 17 – Mar 3), Tomatillo (Feb 17 – Mar 3), Tomato (Feb 17 – Mar 3), Broccoli (Feb 24 – Mar 10), Brussels Sprouts (Feb 24 – Mar 10), Cabbage (Feb 24 – Mar 10), Cauliflower (Feb 24 – Mar 10), Kale (Feb 24 – Mar 10), Basil (Mar 3 – Mar 17), Collard Greens (Mar 3 – Mar 17), Endive & Escarole (Mar 3 – Mar 17), Kohlrabi (Mar 3 – Mar 17), Malabar Spinach (Mar 3 – Mar 17), Okra (Mar 3 – Mar 17), Radicchio (Mar 3 – Mar 17), Summer Savory (Mar 3 – Mar 17), Bitter Melon (Mar 10 – Mar 24), Bok Choy / Pak Choi (Mar 10 – Mar 24), Cucamelon (Mar 10 – Mar 24), Fennel (Bulb) (Mar 10 – Mar 24), Lettuce (Mar 10 – Mar 24), Luffa (Loofah Gourd) (Mar 10 – Mar 24), Napa Cabbage (Mar 10 – Mar 24), New Zealand Spinach (Mar 10 – Mar 24), Peanut (Mar 10 – Mar 24), Swiss Chard (Mar 10 – Mar 24), Watercress (Mar 10 – Mar 24), Cantaloupe / Muskmelon (Mar 17 – Mar 31), Cucumber (Mar 17 – Mar 31), Pumpkin (Mar 17 – Mar 31), Sunflower (Mar 17 – Mar 31), Watermelon (Mar 17 – Mar 31), Winter Squash (Mar 17 – Mar 31), Zucchini / Summer Squash (Mar 17 – Mar 31).
What to plant in March in other states
Dates are computed from Delaware’s statewide average frost dates (from NOAA/NCEI climate normals) and each crop’s timing in our crop database. Your garden may be a week or two either side - for dates tuned to your ZIP code, use the planting calendar.