Zone 4b planting calendar

What to plant in August: zone 4b

A rule-of-thumb starting point for zone 4b: last spring frost around May 15, first fall frost around September 25. Zones are set by winter lows, not frost dates, so two gardens in the same zone can be weeks apart. Measure your ZIP below for dates from your area's own 30-year record.

These are zone-average dates. Check an area-level frost estimate from thirty years of nearby weather history and this calendar retimes itself.
Typical last frost: May 15
Typical first frost: September 25
Winter lows: -25 to -20 °F
Zone 4b Almanac. What growers here actually recorded: sowing weeks, days to first pick, and yields.

Direct sow for fall

  • Beetaround Aug 1

    Counts back 55 days from your first frost. Takes a light frost with cover.

  • Dillaround Aug 1

    Counts back 45 days from your first frost. Frost-tender: must finish before frost.

  • Spinach2 sowings: Aug 6 and Aug 27

    Succession sowing 2 of 3. Sow every 21 days for a steady cut. Sowing again a few weeks later keeps the harvest coming instead of arriving all at once.

  • Lettucearound Aug 6

    Counts back 50 days from your first frost. Takes a light frost with cover.

  • Radish2 sowings: Aug 9 and Aug 23

    Succession sowing 3 of 3. Sow every 14 days for a steady cut. Sowing again a few weeks later keeps the harvest coming instead of arriving all at once.

  • Cilantroaround Aug 11

    Counts back 45 days from your first frost. Takes a light frost with cover.

Transplant for fall

  • Broccoliaround Aug 2

    Last safe transplant date to mature (65 days) before frost on 09-25.

  • Kalearound Aug 12

    Last safe transplant date to mature (55 days) before frost on 09-25.

Sow cover crop

Turn this into your own calendar

Want this calendar emailed to you?

Get the full 12-month version for your ZIP area. Every sowing, transplant, and harvest window, with reminders you can add to your calendar.

Build my free plan Find my zone & frost dates