Fall planting calculator

Calculate a latest sowing or transplant date from your local fall freeze date, days to maturity and an allowance for slower growth.

01 / LOCATION AND START DATELocationHistorical fall freeze probabilityProposed sowing or transplant date

The fall boundary uses the year of this date. It never silently rolls into next year.

02 / READ THE SEED PACKETYour packet counts maturity fromDays to maturityExtra days for slower autumn growth

14 days is an editable starting assumption. Daylight, temperature and variety can require a different allowance.

FALL PLANTING DATES

Choose your starting date.

SELECTED FALL FREEZE BOUNDARY—

CALCULATED LATEST START—

Freeze boundary minus maturity days and your extra allowance.

PROJECTED MATURITY WITH ALLOWANCE—

This checks the time available, not whether a crop can grow under the expected conditions.

Read the local frost-date guide →

How the fall planting calculation works

Some packets count from sowing, others from transplanting. Match your proposed date to that starting point. A transplant’s earlier indoor growing time is not included here.

Cool weather and shorter days can delay growth. University of Maryland Extension uses an extra 10–14 days in its fall-planting calculation; this regional rule is a starting assumption, not a nationwide growth model. Higher latitudes and local conditions may need a different margin.

Cold-tolerant crops may continue beyond a 32°F freeze, while tender crops can need protection sooner. A result that fits the calendar is not a promise of a harvest, suitable soil temperatures, or frost-free weather.

Sources: Maryland Extension: fall-planting arithmetic · Our NOAA data and probability method.