Zone 3a planting calendar

What to plant in August: zone 3a

Zone 3a averages its last spring frost around May 30 and its first fall frost around September 10. Everything below is timed from those two dates, so it stays useful whether you're planting for summer or for a fall harvest.

These are zone-average dates. Check an area-level frost estimate from thirty years of nearby weather history and this calendar retimes itself.

Last frost: May 30

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

Radisharound Aug 8
Succession sowing 2 of 3. Sow every 14 days for a steady cut.
Spinacharound Aug 12
Counts back 40 days from your first frost. Frost-hardy: light freezes sweeten it.
Radisharound Aug 22
Counts back 30 days from your first frost. Frost-hardy: light freezes sweeten it.

Sow cover crop

Cover crop (cereal rye + crimson clover)around Aug 11
Sown a month before frost it germinates, holds your soil all winter, and feeds it in spring.

Plant to overwinter

Garlicaround Aug 27
Cloves go in about two weeks before first frost. They root now, sleep, then bulb next summer.

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