Succession and fall planting: counting back from your first frost

Last updated October 19, 2026 · Sources: cited below

Most gardens are planted once, in spring, and harvested in a rush in midsummer. Two techniques spread the harvest across the whole season: succession planting (sowing small batches every few weeks) and fall planting (a second round of crops timed to mature as the weather cools). Both depend on one number — your first fall frost date — and on simple arithmetic. This guide walks through the calculation with real dates from our city pages.

Know your season

The median frost-free season across the 460 cities on this site with frost dates is 228 days, but it varies enormously. The shortest in our list are Bend, OR (105 days), Fairbanks, AK (112 days), Flagstaff, AZ (115 days); at the other end, several cities in Florida and Southern California have no regular frost season at all. Your city page shows the season at three probability levels and as a chart, plus the 28°F hard-freeze dates, which matter for hardy fall crops.

Succession planting

Succession planting means sowing a little of a quick crop at regular intervals instead of all at once. Cornell Cooperative Extension's example is lettuce: sow just enough for a couple of weeks of salads, then sow again two or three weeks later, and repeat.¹

• Every 1–2 weeks: radishes, baby greens, cilantro.
• Every 2–3 weeks: lettuce, spinach, bush beans, beets, carrots.
• Two or three plantings per season: sweet corn, cucumbers, summer squash — enough to replace a tired first planting.

For each crop, succession stops at a last sowing date: the latest date that still leaves enough time to mature before frost (for tender crops) or before days get too short and cold (for hardy ones). That is the calculation below.

Counting back from the first frost

Virginia Cooperative Extension gives a simple formula for the latest planting date.² Add up:

1. days to maturity from the seed packet (from transplanting, if you set out transplants);
2. the days from seed to transplant, if you grow your own transplants;
3. the length of the harvest period you want;
4. a fall factor of about two weeks, because growth slows as days shorten and cool;
5. a frost-tender factor of two more weeks for crops killed by frost (beans, corn, cucumbers, squash, tomatoes), so they mature before it arrives.

Count that many days back from your first fall frost date. The UC Master Gardeners of Sonoma County use a similar method, adding 7–14 days for shorter, cooler days.³ They also point out that cool-season crops nearly stop growing once days are shorter than about 10 hours, so in mild climates the 10-hour day, not frost, sets the deadline.

Worked example: bush beans in three cities

Take a 55-day bush bean with a 3-week (21-day) harvest. It is frost-tender, so: 55 + 21 + 14 (fall factor) + 14 (frost-tender factor) = 104 days. Counting back from the 30%-risk first frost:

If you would rather risk less, use the 10% first-frost date instead, which is 8 days earlier in Denver and 10 days earlier in Akron.

Worked example: broccoli transplants

Broccoli tolerates light frost, so there is no frost-tender factor, and you can use the 28°F hard-freeze date as the real deadline. A 60-day variety set out as transplants, with a 2-week harvest: 60 + 14 + 14 = 88 days before the hard-freeze date. In Akron, where the median 28°F first freeze is Nov 7, that means transplanting by about Aug 11. The planting calendar on each city page uses a similar rule — 10–12 weeks before the 30%-risk first frost — which is a little more conservative.

A sample season: Akron, Ohio

Here is how the calendar rules on this site play out for Akron, using its 30%-risk dates (last spring frost Apr 30, first fall frost Oct 22):

The gap between the spring and fall columns is midsummer, when lettuce and spinach tend to bolt in the heat. Beans fill that gap. Radishes fit almost anywhere a crop has just come out.

Fall planting in hot-summer climates

In the South and the low desert, the challenge is heat, not frost. In Atlanta, the 30%-risk first frost is Nov 1, so broccoli transplants go in around the middle of August by the 10–12-week rule — often during a heat wave. Shade cloth for the first week, transplants rather than seed, and daily watering make that work. In frost-free or nearly frost-free places, the main cool-season planting simply moves into fall and winter.

What to plant for fall

Cool-season crops that handle light frost are the core of a fall garden: kale, cabbage, broccoli, spinach, lettuce, radishes, beets, carrots and peas. Virginia Cooperative Extension also lists succession plantings of warm-season crops such as corn and beans, harvested until the first killing frost.² Kale and collards often taste sweeter after frost.

Cornell's county guide gives a week-by-week sequence for a first-frost date in early October, starting with beans, cucumbers and summer squash about 12 weeks before frost, moving to broccoli and cabbage transplants at 10–8 weeks, and finishing with spinach, arugula and radishes 5–4 weeks before frost.¹ The same sequence applies anywhere; just shift it to your own date.

Practical tips for summer sowing

• Keep seedbeds moist. Midsummer soil dries fast; water lightly every day until seedlings emerge, or lay a board or shade cloth over the row for a few days.
• Pre-sprout seeds. Virginia Cooperative Extension notes that pre-sprouting can cut two to five days off the fall factor.²
• Use transplants for slow crops. Broccoli, cabbage and kale started indoors in early summer skip the hottest weeks in the ground.
• Choose fast varieties. For late plantings, pick the shortest days-to-maturity you can find.
• Stretch the season with covers. A row cover or cold frame can add weeks to a fall harvest; Utah State's season-extension guide covers the options and warns about overheating on sunny days.⁴

Overwintering crops

Some fall plantings are not harvested in fall at all. Spinach and kale sown four to eight weeks before the first frost can sit through winter under a row cover or in a cold frame in many zone 6 and warmer gardens, then resume growth in late winter for a very early harvest. Garlic is planted around the first frost for harvest the next summer; Cornell's county guide puts it in early October for a first-killing-frost date of October 9.¹ Utah State's season-extension guide explains how cold frames and low tunnels trap heat and why they must be vented on sunny days.⁴

The 28°F hard-freeze date on your city page is a useful marker here: light frosts sweeten kale and do little harm to spinach, but after repeated hard freezes most leafy crops stop growing until spring.

In frost-free climates

Where frost is rare, the “fall garden” is really the main garden. Cool-season crops are planted from September through February, and warm-season crops in late winter and again in late summer, avoiding the hottest months. Our city pages for those 52 cities show seasonal windows rather than frost-based dates.

To get the inputs for these calculations, open your city page. To understand which frost date to use, read Frost dates explained.

More guides: How to read your hardiness zone · Frost dates explained · Why the 2023 hardiness zone map looks warmer · Microclimates