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Longmont, CO planting calendar

When to plant vegetables in Longmont, CO (USDA hardiness zone 6a). Typical last spring frost around May 7, 2026 11 days year to year), first fall frost around Oct 5, 20269 days).

Playing it safe? Spring frost holds off until about May 21, 2026 in roughly 9 years out of 10 — a good target for tender crops like tomatoes and peppers.

Want exact dates for your address, a drag-and-drop bed layout, and reminders when it’s time to sow? Enter your ZIP:

Or get a printable Longmont calendar and sowing reminders by email:

Still time to plant

As of today, these crops can still reach harvest before Longmont, CO’s first frost (~Oct 5, 2026) — fastest first.

Month by month in Longmont, CO

January

February

March

April

May

June

July

August

Understand your frost dates

Frost dates are NOAA 1991–2020 climate normals for a representative location in Longmont, CO (covering 3 ZIPs); your exact dates depend on your address. Schedules are guidance, not guarantees.