If you're in USDA Zone 6 — most of the Midwest and mid-Atlantic, including Kansas City, Indianapolis, Pittsburgh, southern New England — your average last frost is around April 15 (Zone 6a) to April 10 (Zone 6b). Your average first frost is around October 20 to October 25. That gives you a frost-free growing window of roughly 180-190 days.
Here's the full calendar of when to start, sow, and transplant common vegetables based on those dates. All dates assume Zone 6a (last frost April 15). For 6b, shift everything 5 days earlier.
These tolerate frost and like cool soil. Plant before April 15.
| Vegetable | Method | Date |
|---|---|---|
| Spinach | Direct sow | March 18 (4 wks before last frost) |
| Peas | Direct sow | March 18 |
| Arugula | Direct sow | March 25 |
| Radishes | Direct sow | March 25 |
| Kale | Direct sow | March 25 |
| Turnips | Direct sow | March 25 |
| Lettuce | Direct sow | April 1 |
| Carrots | Direct sow | April 1 |
| Beets | Direct sow | April 1 |
| Cilantro | Direct sow | April 1 |
| Potatoes | Plant seed potatoes | April 1 |
| Onions (sets) | Plant outdoors | March 25 |
These need a head start to produce in your growing window. Start under lights, transplant after last frost.
| Vegetable | Start indoors | Transplant outside |
|---|---|---|
| Tomatoes | March 4 (6 weeks before) | April 29 (2 wks after) |
| Peppers (sweet & hot) | February 18 (8 wks before) | May 6 (3 wks after) |
| Eggplant | February 18 | May 6 |
| Broccoli | March 4 | April 1 (2 wks before) |
| Cauliflower | March 4 | April 1 |
| Cabbage | March 4 | April 1 |
| Brussels sprouts (for fall harvest) | March 18 | August 5 |
| Onions (from seed) | February 4 (10 wks before) | March 25 |
| Basil | March 4 | April 29 |
| Parsley | February 18 | April 1 |
These don't transplant well — sow seeds directly in warm soil after last frost.
| Vegetable | Direct sow date |
|---|---|
| Bush beans | April 22 (1 wk after last frost) |
| Pole beans | April 22 |
| Sweet corn | April 22 |
| Cucumbers | April 22 |
| Summer squash / Zucchini | April 22 |
| Winter squash / Pumpkins | April 29 (2 wks after) |
| Melons (watermelon, cantaloupe) | April 29 |
| Dill | April 8 (1 wk before) |
Plant in fall, around your first frost (October 20). Cloves go 4 inches deep, root-end down. Mulch heavily. Harvest the following July when bottom leaves yellow.
These need warm soil. Don't plant slips (not seeds — sweet potatoes grow from rooted slips) until at least May 6, when soil is consistently 65°F+.
For continuous harvest, plant cool-season crops every 2-3 weeks until late spring, then again starting late July for fall harvest. Lettuce, spinach, radishes, and arugula all bolt in summer heat — give yourself a fall round.
"Average last frost" is just an average. There's about a 50% chance your real last frost will be earlier and 50% it'll be later. To be safe with frost-tender plants, wait until 1-2 weeks past your average last frost date, OR be prepared to cover them with frost cloth or cloches if a late freeze is forecast.
Memorial Day weekend is the traditional "safe" planting date in Zone 6 for tender crops like tomatoes and peppers. May 25 is past virtually all real-world last-frost risk.
Your specific yard matters. Urban heat island effects, south-facing slopes, windbreaks, and elevation all shift your real frost dates by days or weeks from the regional average. The only way to know what works for your specific spot is to track planting dates for a few seasons and see what struggled vs. thrived.
Henalytics auto-detects your USDA zone from your location and generates seed-start, transplant, and harvest dates for 30+ crops. Free, no signup required to use.
Open Henalytics →The first year you keep records, the calendar above is gospel. By year three, your records overrule it.
🌱