The most reliable way to time a vegetable garden is to count from your average last spring frost date. Cool-season crops (peas, spinach, lettuce) go out weeks before it; warm-season crops (tomatoes, peppers, beans, squash) go out after it, once the soil warms.
Rules of thumb
- About 10–8 weeks before
Start peppers, eggplant, cabbage, broccoli and head lettuce indoors (onions even earlier, about 14 weeks).
- About 7–5 weeks before
Start tomatoes indoors.
- About 4 weeks before
Once soil is 40–50°F, direct sow peas, spinach, radish and lettuce; set out cabbage-family transplants and onions; plant potatoes, carrots and beets.
- At and after the last frost
With soil at 50–60°F, sow beans, sweet corn, cucumbers and squash and transplant tomatoes and basil.
- About 2–3 weeks after
Transplant peppers and eggplant.
Week-by-week table
| Crop | Start indoors | Plant outside | How |
|---|---|---|---|
| Tomato | 7 wk before → 5 wk before | frost → 2 wk after | transplant |
| Pepper | 10 wk before → 8 wk before | 2 wk after → 3 wk after | transplant |
| Eggplant | 10 wk before → 8 wk before | 2 wk after → 3 wk after | transplant |
| Cabbage / broccoli | 10 wk before → 8 wk before | 5 wk before → 3 wk before | transplant |
| Lettuce | 10 wk before → 8 wk before | 4 wk before → 2 wk after | sow or transplant |
| Onion | 14 wk before → 12 wk before | 4 wk before → 3 wk before | sow or transplant |
| Pea | — | 4 wk before → 2 wk before | direct sow |
| Spinach | — | 4 wk before → 3 wk before | direct sow |
| Radish | — | 4 wk before → frost | direct sow |
| Carrot | — | 4 wk before → 3 wk after | direct sow |
| Beet | — | 4 wk before → 4 wk after | direct sow |
| Potato | — | 4 wk before → frost | direct sow |
| Bean (snap) | — | frost → 7 wk after | direct sow |
| Sweet corn | — | frost → 4 wk after | direct sow |
| Cucumber | — | 1 wk before → 3 wk after | direct sow |
| Squash / zucchini | — | frost → 1 wk after | direct sow |
| Basil | — | frost → 2 wk after | transplant |
| Kale | — | 4 wk before → 7 wk after | direct sow |
Finding your frost date
Your USDA hardiness zone tells you winter lows, not frost dates, so zones are only a rough proxy. Look up local frost/freeze probabilities from NOAA climate normals or ask your county extension office.
Turn your frost date into a printable timeline.
Open itSources
- Virginia Cooperative Extension, "Companion Planting in Gardening" (SPES-620P)
- University of Maryland Extension, "Vegetable Succession and Companion Planting"
- Oregon State University Extension, "Companion Planting"
- Penn State Extension, "Herbs Make Good Plant Partners and Companions"
- University of Minnesota Extension, "Planting the vegetable garden"
- USDA Plant Hardiness Zone Map
- NOAA NCEI U.S. Climate Normals (frost/freeze data)
Pairings are summarized in our own words from extension-service guidance. Research support for many companion effects is limited, so treat them as good habits, not guarantees.