Planting & Harvest Dates

Planting Calendar

Enter your US ZIP code to get a custom planting calendar showing when to start seeds indoors and when to plant outside for 20 common vegetables, based on your average frost dates.

How to use the planting calendar

Type your five-digit US ZIP code into the box and press Show My Planting Calendar. The calculator matches your ZIP to its region, pulls up your average last spring frost and first fall frost, and builds a table of all 20 vegetables. For each crop you will see when to start seeds indoors, when to move plants outside (or direct sow), and a short note with growing tips. If your exact ZIP is not in the database, try a nearby town or larger city for a close estimate.

Why frost dates drive the whole calendar

Almost every planting decision in a vegetable garden is anchored to two dates: the last spring frost and the first fall frost. The last frost tells you when it becomes safe to set out tender, frost-sensitive crops such as tomatoes, peppers, basil, and squash. The first fall frost marks the end of the season for those same crops. By counting weeks from these two dates, you can schedule indoor sowing, outdoor planting, and harvest so each crop gets the weather it prefers.

Cool-season versus warm-season crops

The vegetables in this calendar fall into two broad camps. Cool-season crops — spinach, lettuce, peas, kale, broccoli, carrots, radishes, and beets — thrive in chilly weather and tolerate light frost, so many of them go in the ground weeks before your last frost and again in late summer for a fall crop. Warm-season crops — tomatoes, peppers, eggplant, cucumbers, zucchini, beans, corn, basil, and squash — need warm soil and frost-free nights, so they wait until on or after your last frost date.

Indoor seed starting versus direct sowing

Slow-maturing crops benefit from a head start indoors under lights or on a bright windowsill, then get transplanted once the weather cooperates. Tomatoes, peppers, eggplant, onions, broccoli, kale, lettuce, basil, and parsley all follow this pattern in the calendar. Other crops dislike having their roots disturbed and are best seeded straight into the garden: carrots, radishes, beets, beans, peas, corn, cucumbers, zucchini, and squash are all direct sown. The table labels these clearly so you know which approach each crop needs.

Tips for a successful planting season

  • Harden off indoor-grown seedlings over 7–10 days before transplanting so they adjust to wind and sun.
  • Watch the forecast: these dates are averages, and a late cold snap can still nip tender plants.
  • Keep lightweight row cover on hand to protect young plants from surprise frosts.
  • Sow quick crops like radishes and lettuce in small batches every couple of weeks for a steady harvest.
  • Warm raised beds and dark mulch help warm-season crops get going a little earlier in spring.

Frequently Asked Questions

How does the planting calendar know my dates?

You enter your five-digit US ZIP code, and the calculator reads the first three digits to find your region. It then looks up your average last spring frost and first fall frost from 30-year NOAA climate data, and counts weeks forward or backward from those dates using standard timing for each crop. The result is a calendar tailored to your local growing season rather than a generic national chart.

What is the difference between starting indoors and transplanting outside?

Starting indoors means sowing seeds in pots or trays under lights or on a windowsill weeks before it is warm enough to plant outdoors. This gives slow crops like tomatoes, peppers, and onions a head start. Transplanting outside is when you move those young plants into the garden. Crops in the "Direct sow" rows skip the indoor step entirely and are seeded straight into garden soil.

Which vegetables should not be started indoors?

Root crops and fast growers generally resent transplanting and do best sown directly in the ground. Carrots, radishes, beets, beans, peas, corn, cucumbers, zucchini, and squash all fall into this group. Moving them disturbs their roots and can cause forked carrots or stalled growth, so the calendar lists a single direct-sow date for them instead of an indoor start.

Why are some vegetables planted before the last frost?

Cool-season crops such as spinach, peas, lettuce, kale, broccoli, carrots, and beets tolerate or even prefer cold soil and light frost. Planting them several weeks before your last frost lets them mature in cool weather and finish before summer heat makes them bitter or causes them to bolt. Warm-season crops like tomatoes and basil are the opposite and must wait until after frost has passed.

Why is garlic on a completely different schedule?

Garlic is planted from individual cloves in the fall, not in spring, and it needs a cold period over winter to form good bulbs. The calendar schedules it about six weeks before your first fall frost so roots establish before the ground freezes. It then sits dormant through winter and is harvested the following summer, making it one of the longest-season crops in the garden.

How accurate are these planting dates?

The dates are solid planning guidelines built from 30-year average frost data and typical seed-packet timing, but they are averages, not guarantees. Roughly half of years will see frost a little later in spring or earlier in fall, and local microclimates can shift your real dates by a week or more. Always check the short-term forecast before planting tender crops, and keep row covers handy for surprise late frosts.

My ZIP code was not found. What should I do?

This calculator covers a wide range of US ZIP prefixes but not every single one. If yours is not listed, enter the ZIP code of a nearby town or a larger city in your area. Frost dates change gradually across a region, so a neighboring ZIP will give you a very close estimate for your own garden.

Related Tools

Frost Date Calculator Open tool → Square Foot Garden Planner Open tool → Plant Spacing Calculator Open tool →
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GardenCalc Editorial Team

Horticulture writers & master gardeners

Our calculators and growing guides are written and fact-checked by gardeners with hands-on experience in vegetable production, soil management, and home landscaping.