Zone 3b planting calendar

What to plant in April: zone 3b

Zone 3b averages its last spring frost around May 25 and its first fall frost around September 15. 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 25
First frost: September 15
Winter lows: -35 to -30 °F
Zone 3b Almanac. What growers here actually recorded: sowing weeks, days to first pick, and yields.

Dormant care

  • Pre-sprout seed potatoesaround Apr 13

    Chit potatoes in a bright, cool spot for 2 weeks. Sprouted pieces jump ahead once planted.

Start indoors

  • Tomatoaround Apr 13

    6 weeks of indoor growth before your last frost (05-25). Bury 2/3 of the transplant stem. Roots form along the buried stem for a stronger plant.

  • Kalearound Apr 13

    6 weeks of indoor growth before your last frost (05-25). Fall crop sweetens after first frost. Plan a July sowing for the best flavor.

  • Broccoliaround Apr 13

    6 weeks of indoor growth before your last frost (05-25). After cutting the main head, side shoots keep coming for weeks: don't pull the plant.

  • Basilaround Apr 13

    6 weeks of indoor growth before your last frost (05-25). Pinch flower spikes the moment you see them: leaves stay sweet all season.

  • Cabbagearound Apr 13

    6 weeks of indoor growth before your last frost (05-25). Firm heads need steady water and steady nitrogen. Once a head feels solid, cut it: leaving it in summer heat splits it open overnight.

  • Caulifloweraround Apr 13

    6 weeks of indoor growth before your last frost (05-25). Cauliflower is the fussiest brassica: any check in water or nitrogen makes it button into a tiny head. Blanch white types by tying outer leaves over the curd.

  • Brussels Sproutsaround Apr 13

    6 weeks of indoor growth before your last frost (05-25). This is a fall crop: frost is what turns the sprouts sweet. Around 4 weeks before harvest, top the growing tip so the plant pushes size into the sprouts.

  • Kohlrabiaround Apr 13

    6 weeks of indoor growth before your last frost (05-25). Harvest the swollen stem at tennis-ball size, no bigger: past that it turns woody and fibrous fast.

  • Romanescoaround Apr 13

    6 weeks of indoor growth before your last frost (05-25). It's slower and fussier than cauliflower; give it the longest cool-weather window you can, spring or fall, not summer.

  • Radicchioaround Apr 13

    6 weeks of indoor growth before your last frost (05-25). Cool fall weather brings out its best deep red color and mellows bitterness; grow it as a fall crop where possible.

  • Sorrelaround Apr 13

    6 weeks of indoor growth before your last frost (05-25). Snip flower stalks as they appear to keep leaves tender; the lemony tang fades if the plant is allowed to bolt.

  • Summer Savoryaround Apr 13

    6 weeks of indoor growth before your last frost (05-25). Harvest just before flowering for the best flavor, then shear the whole plant back for a second flush.

  • Chamomile (German)around Apr 13

    6 weeks of indoor growth before your last frost (05-25). Pick flowers at midday once fully open, on a dry day, for the strongest tea; it dries quickly on a screen out of direct sun.

  • Collardsaround Apr 20

    5 weeks of indoor growth before your last frost (05-25). The most forgiving green in the garden. Harvest bottom leaves upward and it produces for months. Leaves picked after a frost are noticeably sweeter.

  • Napa Cabbagearound Apr 20

    5 weeks of indoor growth before your last frost (05-25). Grow it as a fall crop where possible: napa bolts in spring heat but forms a tight, sweet head in cooling fall days.

  • Lettucearound Apr 27

    4 weeks of indoor growth before your last frost (05-25). Succession sow every 2 weeks. Harvest outer leaves for a cut-and-come-again supply.

  • Swiss Chardaround Apr 27

    4 weeks of indoor growth before your last frost (05-25). Cut outer stalks 2 in above the crown and the plant keeps producing from spring into hard frost. One planting can feed a household all season.

  • Bok Choyaround Apr 27

    4 weeks of indoor growth before your last frost (05-25). Bolts fast once days lengthen past 14 hours. Grow it as an early spring or fall crop, not a summer one.

  • Endivearound Apr 27

    4 weeks of indoor growth before your last frost (05-25). Blanch heads by tying outer leaves shut 2 weeks before harvest to mellow the natural bitterness.

  • Escarolearound Apr 27

    4 weeks of indoor growth before your last frost (05-25). Broader and milder than curly endive; a light frost sweetens the outer leaves before harvest.

Transplant out

  • Raspberryaround Apr 13

    Goes out 6 weeks before last frost. It takes the cold.

  • Blueberryaround Apr 13

    Goes out 6 weeks before last frost. It takes the cold.

  • Applearound Apr 13

    Goes out 6 weeks before last frost. It takes the cold.

  • Rhubarbaround Apr 13

    Goes out 6 weeks before last frost. It takes the cold.

  • Asparagusaround Apr 27

    Goes out 4 weeks before last frost. It takes the cold.

  • Horseradisharound Apr 27

    Goes out 4 weeks before last frost. It takes the cold.

Direct sow

  • Napa Cabbagearound Apr 13

    Soil is ready -6 weeks before last frost.

  • Fava Beanaround Apr 13

    Soil is ready -6 weeks before last frost.

  • Radicchioaround Apr 13

    Soil is ready -6 weeks before last frost.

  • Mâche (Corn Salad)around Apr 13

    Soil is ready -6 weeks before last frost.

  • Peaaround Apr 20

    Soil is ready -5 weeks before last frost.

  • Lettucearound Apr 27

    Soil is ready -4 weeks before last frost.

  • Spinacharound Apr 27

    Soil is ready -4 weeks before last frost.

  • Radisharound Apr 27

    Soil is ready -4 weeks before last frost.

  • Turniparound Apr 27

    Soil is ready -4 weeks before last frost.

  • Arugulaaround Apr 27

    Soil is ready -4 weeks before last frost.

  • Mizunaaround Apr 27

    Soil is ready -4 weeks before last frost.

  • Tatsoiaround Apr 27

    Soil is ready -4 weeks before last frost.

  • Mustard Greensaround Apr 27

    Soil is ready -4 weeks before last frost.

  • Broccoli Raabaround Apr 27

    Soil is ready -4 weeks before last frost.

  • Shallotaround Apr 27

    Soil is ready -4 weeks before last frost.

  • Endivearound Apr 27

    Soil is ready -4 weeks before last frost.

  • Escarolearound Apr 27

    Soil is ready -4 weeks before last frost.

  • Orach (Mountain Spinach)around Apr 27

    Soil is ready -4 weeks before last frost.

Garden care

  • Wake the bedsaround Apr 20

    Turn in compost, cut down cover crops, and let the soil warm two weeks before the first sowing.

  • Harden off early transplantsaround Apr 27

    Two weeks of increasing outdoor time keeps cold-hardy seedlings from stalling when they go out.

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