Colorado planting calendar

When to plant chives in Colorado — sow, transplant & harvest dates

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

Chives planting timetable for Colorado

Stage	When in Colorado	Anchor
Start seeds indoors	early April (April 3)	6 weeks before the last frost (mid-May)
Transplant outside	early May (May 1)	14 days before the last frost (mid-May)
First harvest (estimate)	late June (June 30)	~60 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 Colorado's climate shifts the chives dates

Colorado's last spring frost averages mid-May and first fall frost late September, which sets the whole planting clock. Colorado gardening is shaped by altitude, intense sun, low humidity, and big day-night temperature swings. Frost can come in any month at high elevation. Wait for warm soil — chives stall in cold ground even after the air warms, so don't rush them out.

Start seeds indoors 6–8 weeks before the last spring frost; germination takes 7–14 days at 18–21 °C (65–70 °F), though seeds will germinate across a broad range of 15–35 °C (60–95 °F). As a cold-hardy perennial (zones 3–9), transplants can go out 1–2 weeks before the last frost once soil is workable — or direct-sow as soon as the ground can be worked in early spring. Begin snipping leaves about 30 days after transplanting (or ~60 days from seed) once plants reach 15 cm (6 in) tall; divide clumps every 3–4 years to maintain productivity.

Frost-risk note

Don't plant before mid-May — a hard freeze can still set young plants back. In the high Rockies and mountain valleys (zone 3b-4b) the safe date runs a week or two later.

Regional variation within Colorado

the high Rockies and mountain valleys (zone 3b-4b) runs roughly 1-2 weeks behind the state average; the western slope around Grand Junction (zone 7a) can plant 1-2 weeks earlier.

Denver — USDA zone 6a
Colorado Springs — USDA zone 6a
Boulder — USDA zone 6a
Grand Junction — USDA zone 7a
Fort Collins — USDA zone 5b

What else to plant in Colorado around then

Pair the post-frost slot with other warm-season crops — peppers, beans, squash, and cucumbers.

Quick-grow guide

Sun: Full sun to partial shade — 4–6+ hours direct.
Soil temperature for germination: 15–21 °C (60–70 °F).
Spacing: 6–12 inches (15–30 cm) between plants.
Days to harvest: ~60 days from planting out.

Frequently asked questions

When is the best time to plant chives in Colorado?

In Colorado (mostly USDA zone 5b), sow chives indoors around early April, transplant outdoors early May (before the last frost, mid-May), and harvest from late June. Chives 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 Colorado?

Most of Colorado sits in USDA hardiness zone 5b, with the state spanning roughly 3b-7a from the high Rockies and mountain valleys (zone 3b-4b) to the western slope around Grand Junction (zone 7a). The last spring frost averages mid-May and the first fall frost late September.

Can you grow chives in Colorado?

Yes. Colorado's dominant zone 5b supports chives — the key is timing. Chives 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 Colorado?

the high Rockies and mountain valleys (zone 3b-4b) runs roughly 1-2 weeks behind the state average; the western slope around Grand Junction (zone 7a) can plant 1-2 weeks earlier.

What else can I plant in Colorado around the same time?

Pair the post-frost slot with other warm-season crops — peppers, beans, squash, and cucumbers.

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.