Early spring bulbs pushing through soil
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March in Zone 5

March in Zone 5: soil thaws; direct sow hardiest crops late in the month. Start brassicas and cucurbits indoors.

Quick answer · Updated July 2026

In March, Zone 5 gardeners can plant Broccoli, Cabbage, Cauliflower, Cucumbers, Squash, Melons, Peas, and Spinach. Zone 5's last frost is around Late April – early May and first frost around Early – mid October — the full task list below has exact timing for each crop.

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Min Winter Temp
-20 to -10 °F / -29 to -23 °C
Last Spring Frost
Late April – early May
First Fall Frost
Early – mid October
Growing Season
150–180 days
Annual Rainfall
25–50 in

Gardening in March in Zone 5

March is the depth of winter in Zone 5. With the last spring frost not due until around Late April – early May, the garden is dormant and the real work is planning — ordering seeds, sketching beds, and starting only the longest-season crops indoors.

The planting focus in Zone 5 this month is Broccoli, Cabbage, Cauliflower, Cucumbers, Squash, and Melons — see the task cards below for exactly how and when to sow each in your conditions.

About March in the garden

March is the month of transition. Cold-zone gardeners begin direct sowing the hardiest crops; warm-zone gardeners are in full spring planting mode. Spring equinox brings equal day and night, and soil temperatures begin to rise significantly.

Direct sowing peas, spinach, and lettuce in cold zones; transplanting tomatoes and peppers in Zone 9–10; pruning and dividing perennials; preparing beds.

Season
spring
Temperature trend
Rapidly warming in most regions; significant week-to-week temperature changes.
Daylight
Spring equinox (around March 20); days and nights are equal length, then days lengthen rapidly.
Zone 5 last frost
Late April – early May
Zone 5 first frost
Early – mid October

6

Sow indoors

2

Sow outdoors

2

Transplant

0

Harvest

0

Maintenance

🌱 Sow indoors

Sow Indoors

Start broccoli, cabbage, and cauliflower indoors

Broccoli

Broccoli

Sow ¼ inch deep; transplant at 4–6 weeks when 4–5 inches tall; space 18 inches apart.

Cabbage

Cabbage

Sow ¼ inch deep; harden off well before transplanting; space 12–18 inches apart.

Cauliflower

Cauliflower

Sow ¼ inch deep; needs consistent cool temperatures; space 18 inches apart.

Sow Indoors

Start cucumbers, squash, and melons indoors (late March, 4 weeks before last frost)

Cucumbers

Cucumbers

Sow 2 seeds per cell ½ inch deep; thin to one seedling; transplant carefully to avoid root disturbance.

Squash

Squash

Follow standard planting guidelines for Squash.

Melons

Melons

Sow ½ inch deep in 4-inch pots; transplant gently 2–3 weeks after last frost.

🌿 Sow outdoors

Sow Outdoors

Direct sow peas and spinach outdoors (late March, soil 40°F+)

Peas

Peas

Sow 1 inch deep, 2 inches apart in a single row alongside a trellis; pre-soak seeds overnight.

Spinach

Spinach

Sow ½ inch deep, 2 inches apart; germinates best at 50–65°F; thin to 6 inches.

🪴 Transplant

Transplant

Transplant onion seedlings outdoors (late March under row cover)

Onions

Onions

Sow ¼ inch deep in seed trays, thin to 1 inch apart; transplant outdoors at pencil thickness.

Leeks

Leeks

Sow ¼ inch deep in trays; transplant into 6-inch-deep trenches for blanching.

When to plant this month's crops in Zone 5

Full planting calendars — start indoors, transplant, and harvest timing — for the crops you're planting in March.

General March tasks

These apply broadly regardless of zone — a useful checklist alongside the zone-specific tasks above.

  • Direct sow peas, spinach, and lettuce outdoors once soil is workable
  • Start cucumbers, melons, and squash indoors (3–4 weeks before last frost)
  • Divide and transplant summer-blooming perennials
  • Apply compost or aged manure to vegetable beds
  • Plant shallots, onion sets, and bare-root strawberries
  • Set up cold frames and row covers for early crops
  • Begin hardening off seedlings started indoors
  • Plant cool-season annuals: pansies, snapdragons

⚠ Watch-outs for March

  • Frost is still possible in most zones through March; protect transplants
  • Soil may still be too wet and cold for many seeds — test by squeezing a handful
  • Late snowfall can flatten young seedlings outdoors; have covers ready
  • Slugs and snails become active early in spring; set bait or traps

March in Zone 5: common questions

What can I plant in March in Zone 5?

In March, Zone 5 gardeners can sow or transplant Broccoli, Cabbage, Cauliflower, Cucumbers, Squash, Melons, Peas, and Spinach. March in Zone 5: soil thaws; direct sow hardiest crops late in the month. Start brassicas and cucurbits indoors.

When is the last and first frost in Zone 5?

Zone 5 typically has its last spring frost around Late April – early May and its first fall frost around Early – mid October, giving a growing season of roughly 150–180 days. Always check a local frost-date source, since microclimates vary.

What garden jobs matter most in March in Zone 5?

Focus on direct sow peas, spinach, and lettuce outdoors once soil is workable, start cucumbers, melons, and squash indoors (3–4 weeks before last frost), divide and transplant summer-blooming perennials. Watch out for frost is still possible in most zones through march; protect transplants.