Zone 5a planting calendar

What to plant in March: zone 5a

Zone 5a averages its last spring frost around May 10 and its first fall frost around October 1. 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 10
First frost: October 1
Winter lows: -20 to -15 °F
Zone 5a Almanac. What growers here actually recorded: sowing weeks, days to first pick, and yields.

Start indoors

  • Start onions and leeks indoorsaround Mar 1

    Alliums need 10-12 weeks under lights before they go out. The earliest sowing of the year.

  • Onionaround Mar 1

    10 weeks of indoor growth before your last frost (05-10). Match day-length to your latitude. Long-day north of 37°, short-day south.

  • Leekaround Mar 1

    10 weeks of indoor growth before your last frost (05-10). Plant seedlings deep in a 6 in trench and hill soil up the stem twice during the season. That buried length is the tender white shaft you're growing for.

  • Celeryaround Mar 1

    10 weeks of indoor growth before your last frost (05-10). Celery is a water crop: it turns stringy and bitter the moment it dries out. Keep soil consistently moist and feed steadily. Homegrown stalks are thinner and far more flavorful than store celery.

  • Lavenderaround Mar 1

    10 weeks of indoor growth before your last frost (05-10). Lean, gritty, well-drained soil and no coddling. Plant on a slight mound, skip the fertilizer, and prune a third of the plant after bloom to stop it going woody.

  • Celeriacaround Mar 1

    10 weeks of indoor growth before your last frost (05-10). Needs a long, steady season: start indoors early and keep soil evenly moist the entire time or the knob stays small.

  • Habanero Pepperaround Mar 1

    10 weeks of indoor growth before your last frost (05-10). Needs more heat and a longer season than bell peppers; start indoors early and don't rush it outside until nights stay above 55F.

  • Pepperaround Mar 15

    8 weeks of indoor growth before your last frost (05-10). Pinch first flowers on transplants so the plant invests in roots before setting fruit.

  • Parsleyaround Mar 15

    8 weeks of indoor growth before your last frost (05-10). Soak seeds 24 hrs before sowing. Cut outer stems and it comes back for years in mild zones.

  • Chivesaround Mar 15

    8 weeks of indoor growth before your last frost (05-10). Divide the clump every 3 years: one plant becomes six with no effort.

  • Oreganoaround Mar 15

    8 weeks of indoor growth before your last frost (05-10). Harvest just before flowering for the strongest flavor. Dries beautifully.

  • Thymearound Mar 15

    8 weeks of indoor growth before your last frost (05-10). Needs sharp drainage. Plant in gravelly soil or a raised bed edge. Never wet feet.

  • Sagearound Mar 15

    8 weeks of indoor growth before your last frost (05-10). Prune hard in spring to prevent woody stems and keep the plant productive for 5+ years.

  • Eggplantaround Mar 15

    8 weeks of indoor growth before your last frost (05-10). Eggplant sulks in cold soil. Transplant 3 weeks after last frost, not on it. Harvest while skin is glossy: dull skin means bitter, seedy flesh.

  • Scallion (Green Onion)around Mar 15

    8 weeks of indoor growth before your last frost (05-10). Sow thickly in a band and harvest by pulling every other plant: the rest fill in the gap.

  • Jalapeño Pepperaround Mar 15

    8 weeks of indoor growth before your last frost (05-10). Corking (light brown cracks near the stem) means the pepper is fully ripe and at peak heat, not damaged.

  • Poblano Pepperaround Mar 15

    8 weeks of indoor growth before your last frost (05-10). Picked green it's a poblano; left to ripen red on the plant and dried, it becomes an ancho chile.

  • Cayenne Pepperaround Mar 15

    8 weeks of indoor growth before your last frost (05-10). Thin-walled pods dry easily on the plant or strung indoors; harvest for drying once fully red.

  • Shishito Pepperaround Mar 15

    8 weeks of indoor growth before your last frost (05-10). Pick while still green and wrinkled for the classic blistered appetizer; about 1 in 10 fruits carries real heat.

  • Lemon Balmaround Mar 15

    8 weeks of indoor growth before your last frost (05-10). Cut back hard before it flowers and sets seed, or it self-sows into every corner of the garden.

  • Lovagearound Mar 15

    8 weeks of indoor growth before your last frost (05-10). Grows 4-6 ft tall once established; give it the back of the bed and divide the crown every few years to keep it productive.

  • Catniparound Mar 15

    8 weeks of indoor growth before your last frost (05-10). Fence it off if cats roam the neighborhood: they'll flatten the plant and any seedlings around it rolling in the scent.

  • Anise Hyssoparound Mar 15

    8 weeks of indoor growth before your last frost (05-10). Deadhead spent spikes to extend bloom all summer; bees and hummingbirds favor it over almost anything else nearby.

  • Tomatoaround Mar 29

    6 weeks of indoor growth before your last frost (05-10). Bury 2/3 of the transplant stem. Roots form along the buried stem for a stronger plant.

  • Kalearound Mar 29

    6 weeks of indoor growth before your last frost (05-10). Fall crop sweetens after first frost. Plan a July sowing for the best flavor.

  • Broccoliaround Mar 29

    6 weeks of indoor growth before your last frost (05-10). After cutting the main head, side shoots keep coming for weeks: don't pull the plant.

  • Basilaround Mar 29

    6 weeks of indoor growth before your last frost (05-10). Pinch flower spikes the moment you see them: leaves stay sweet all season.

  • Cabbagearound Mar 29

    6 weeks of indoor growth before your last frost (05-10). 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 Mar 29

    6 weeks of indoor growth before your last frost (05-10). 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 Mar 29

    6 weeks of indoor growth before your last frost (05-10). 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 Mar 29

    6 weeks of indoor growth before your last frost (05-10). Harvest the swollen stem at tennis-ball size, no bigger: past that it turns woody and fibrous fast.

  • Romanescoaround Mar 29

    6 weeks of indoor growth before your last frost (05-10). It's slower and fussier than cauliflower; give it the longest cool-weather window you can, spring or fall, not summer.

  • Cucamelonaround Mar 29

    6 weeks of indoor growth before your last frost (05-10). Grows from a small tuberous root that overwinters indoors in pots north of zone 7; pick fruit at grape size for the best crunch.

  • Tomatilloaround Mar 29

    6 weeks of indoor growth before your last frost (05-10). Plant at least two for pollination: a single tomatillo rarely sets fruit. Husk turns papery and splits when ripe.

  • Ground Cherryaround Mar 29

    6 weeks of indoor growth before your last frost (05-10). Fruit drops when ripe, husk and all: rake or hand-pick off the ground every few days rather than picking from the plant.

  • Radicchioaround Mar 29

    6 weeks of indoor growth before your last frost (05-10). Cool fall weather brings out its best deep red color and mellows bitterness; grow it as a fall crop where possible.

  • Sorrelaround Mar 29

    6 weeks of indoor growth before your last frost (05-10). Snip flower stalks as they appear to keep leaves tender; the lemony tang fades if the plant is allowed to bolt.

  • Summer Savoryaround Mar 29

    6 weeks of indoor growth before your last frost (05-10). Harvest just before flowering for the best flavor, then shear the whole plant back for a second flush.

  • Chamomile (German)around Mar 29

    6 weeks of indoor growth before your last frost (05-10). 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.

  • Shiso (Perilla)around Mar 29

    6 weeks of indoor growth before your last frost (05-10). Self-sows aggressively once established; pinch spent flower spikes if you don't want volunteers taking over next spring.

  • Anisearound Mar 29

    6 weeks of indoor growth before your last frost (05-10). Needs a long, warm, frost-free season to set seed; stake plants, as the thin stalks flop once seed heads fill out.

  • Epazotearound Mar 29

    6 weeks of indoor growth before your last frost (05-10). Self-sows freely once established; use a light hand in cooking, since the flavor is strong and a little goes a long way.

Dormant care

Direct sow

Transplant out

  • Raspberryaround Mar 29

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

  • Blueberryaround Mar 29

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

  • Blackberryaround Mar 29

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

  • Grapearound Mar 29

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

  • Applearound Mar 29

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

  • Peararound Mar 29

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

  • Peacharound Mar 29

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

  • Rhubarbaround Mar 29

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

  • Plumaround Mar 29

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

  • Cherryaround Mar 29

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

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