New York planting calendar

When to plant onions in New York — sow, transplant & harvest dates

New York is mostly USDA zone 5b (range 3b-7b). Dates below are derived from onions's frost tolerance and New York's frost window — not generic national averages.

Onions planting timetable for New York

Stage	When in New York	Anchor
Start seeds indoors	late February (February 24)	10 weeks before the last frost (early May (upstate) to mid-April (NYC))
Transplant outside	early April (April 7)	28 days before the last frost (early May (upstate) to mid-April (NYC))
First harvest (estimate)	late July (July 26)	~110 days from transplant

Dates are state-wide averages for the dominant zone. Local microclimates — elevation, urban heat, coastal moderation — can shift the window by 1-2 weeks. Use the frost-date calculator for a date tuned to your town.

Why New York's climate shifts the onions dates

New York's last spring frost averages early May (upstate) to mid-April (NYC) and first fall frost early October (upstate) to early November (NYC), which sets the whole planting clock. New York spans cold Adirondack highlands to mild New York City. Most of upstate gardens in zones 5-6; the city and Long Island run much warmer. Sow early — onions bolt once daytime temperatures hold above 24 °C, so the earlier they go in, the longer the harvest.

Onions are day-length sensitive: long-day varieties (zones 1–6) begin bulbing when days exceed 14 hours, short-day types (zones 7–10) bulb at 10–12 hours, and intermediate-day varieties span zones 5–6. Start seeds indoors 10–12 weeks before the last spring frost and transplant out 4–6 weeks before it — young onion seedlings tolerate frost down to about -6 °C once hardened off. In zones 8–10 a second planting from sets in autumn is common, overwintering for an early-summer harvest.

Frost-risk note

Don't plant before early May (upstate) to mid-April (NYC) — a hard freeze can still set young plants back. In the Adirondacks and Tug Hill plateau (zone 3b) the safe date runs a week or two later.

Regional variation within New York

the Adirondacks and Tug Hill plateau (zone 3b) runs roughly 1-2 weeks behind the state average; New York City and Long Island (zone 7b) can plant 1-2 weeks earlier.

New York City — USDA zone 7b
Buffalo — USDA zone 6a
Rochester — USDA zone 6a
Albany — USDA zone 5b
Syracuse — USDA zone 6a

What else to plant in New York around then

The same early window suits peas, lettuce, spinach, and onion sets.

Quick-grow guide

Sun: Full sun — 6+ hours direct.
Soil temperature for germination: 10-35 °C (50-95 °F).
Spacing: 4-6 inches (10-15 cm) between plants.
Days to harvest: ~110 days from planting out.

Frequently asked questions

When is the best time to plant onions in New York?

In New York (mostly USDA zone 5b), sow onions indoors around late February, transplant outdoors early April (before the last frost, early May to mid-April), and harvest from late July. Onions are cold-hardy — they tolerate frost and actively prefer cool weather, so they go in well before the last spring frost and bolt in summer heat.

What USDA zone is New York?

Most of New York sits in USDA hardiness zone 5b, with the state spanning roughly 3b-7b from the Adirondacks and Tug Hill plateau (zone 3b) to New York City and Long Island (zone 7b). The last spring frost averages early May (upstate) to mid-April (NYC) and the first fall frost early October (upstate) to early November (NYC).

Can you grow onions in New York?

Yes. New York's dominant zone 5b supports onions — the key is timing. Onions are cold-hardy — they tolerate frost and actively prefer cool weather, so they go in well before the last spring frost and bolt in summer heat.

Does the planting date change across New York?

the Adirondacks and Tug Hill plateau (zone 3b) runs roughly 1-2 weeks behind the state average; New York City and Long Island (zone 7b) can plant 1-2 weeks earlier.

What else can I plant in New York around the same time?

The same early window suits peas, lettuce, spinach, and onion sets.

Source and methodology

State zone spans from the USDA Plant Hardiness Zone Map (2023); frost-date averages from NOAA Climate Data Online. Hot-state two-season timing cross-checked against the UF/IFAS Florida Gardening Calendar and the University of Arizona Cooperative Extension planting calendar. Curated by the Growli editorial team.