Zone 3a planting calendar

What to plant in August: zone 3a

A rule-of-thumb starting point for zone 3a: last spring frost around May 30, first fall frost around September 10. 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 30
Typical first frost: September 10
Winter lows: -40 to -35 °F
Zone 3a Almanac. What growers here actually recorded: sowing weeks, days to first pick, and yields.

Garden care

  • Scout for pests weeklyaround Aug 1

    Squash bugs, hornworms and cucumber beetles peak now: five minutes of hand-picking beats a rescue spray.

Direct sow for fall

  • Radish2 sowings: Aug 8 and Aug 22

    Succession sowing 2 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.

  • Spinacharound Aug 12

    Counts back 40 days from your first frost. Frost-hardy: light freezes sweeten it.

Sow cover crop

Plant to overwinter

  • Garlicaround Aug 27

    Cloves go in about two weeks before first frost. They root now, sleep, then bulb next summer.

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