longleaf pine (Pinus palustris), photographi

Can I Grow Longleaf Pine in Colorado?

USDA Zones 3b-7b · Plant zone range 7-9

Conditional — Some Areas

longleaf pine (zones 7-9) reaches only part of Colorado (3b-7b): zone 7 are in range, so where you are in the state decides it.

Longleaf Pine in Colorado — the short answer

Longleaf Pine in Colorado: hardy in zones 7–9, full sun, against a state median of ~155 frost-free days.

Plant zones
7-9
Manual horticultural correction (source not retained); NC State Extension and Missouri Botanical Garden, with the remaining rows from other published sources or Growable Ground compilation
Colorado zones
3b-7b
USDA PHZM 2023
Frost window
Apr 25 - May 19 – Sep 29 - Oct 16
NOAA RCC ACIS 1991-2020, 28°F
Shortest county season
85 days
NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — per-field provenance varies and is published with the dataset.

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Your yard isn't the whole zone.

Colorado spans zones 3b-7b, but your yard sits in exactly one — and slope, tree cover, and cold-air pockets nudge it further. Enter your address and we'll score longleaf pine against your parcel's actual hardiness, soil, and sun.

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Colorado is not one climate

Colorado’s winter-low ladder runs across 64 counties, from zone 4.5 in Alamosa County to zone 7 in Mesa County. That is 25°F between the two counties’ average coldest night — the difference between longleaf pine overwintering in the ground and coming under cover.

4.5 zonesAlamosa County7 zonesMesa County

The middle half of 64 counties runs 5.56 zones, with a median of 5.5 zones — a 2.5-zone span end to end.

Measured across 64 Colorado counties. USDA PHZM 2023, per county. Quartiles are order statistics — every figure shown is a value a real county recorded, not an interpolation. Your own site sits somewhere inside this range; a parcel report resolves where.

Where in Colorado Fits Best

Longleaf Pine is rated for zones 79 — a cold floor USDA puts at 0 to 10°F. Against Colorado’s 64 counties that band holds in 2 of them, and the line runs at Delta County (zone 7a), the coldest county still inside it.

Inside zones 7–9

2 counties

0 of 2 shown

Below the zone 7 floor

62 counties

3 of 62 shown

Winter cold is the limit here — the same plant works in a container that comes under cover.

County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. A zone is a 10°F band of average annual extreme minimum temperature, so the floor above is the band the plant's rating denotes, not a single measured kill point. Slope, shelter and cold-air drainage routinely move a site half a zone either way from its county figure — which is the part only your address resolves.

Even within Colorado's zones 3b-7b, county microclimates differ enough to change what thrives. These counties carry the closest zone match for longleaf pine (USDA PHZM 2023):

Zone Comparison

Longleaf Pine Needs

  • USDA Zones: 7-9
  • Frost-Free Days: 270+
  • Sun: Full Sun
  • Mature size: 120 ft tall
  • Drought tolerance: Medium

Colorado Has

  • USDA Zones: 3b-7b
  • Last Hard Freeze (28°F): Apr 25 - May 19
  • First Hard Freeze (28°F): Sep 29 - Oct 16
  • Annual Rainfall: 7-20 inches
  • Common Soils: Sandy loam, Clay loam, Alkaline caliche

Plant Zone Range (zones 7-9)

7a
9b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 4.06.5

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS, and university Extension sources — per-field provenance varies and is published with the dataset. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.

When to Plant Longleaf Pine in Colorado

The frost window

Across Colorado, the last spring hard freeze (28°F) clears between Apr 25 and May 19, and the first fall hard freeze lands between Sep 29 and Oct 16 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 133-day window you can count on — up to 174 days on a mild site in a kind year. That marks the hard freeze, not the last light frost, so tender transplants usually wait another 2-3 weeks.

Winter standing

Colorado runs as cold as USDA zone 3, and no sourced winter-hardiness floor is on record for longleaf pine, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether longleaf pine is a permanent planting or a replant-every-spring crop for you turns on your own zone within Colorado; check its hardiness range against that before treating it as long-lived ground.

Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: Growable Ground Plant Database — frost-free days from FAO ECOCROP, days to harvest from university Extension production guides, and growing-degree-day and chill-hour minimums that are compilation estimates rather than published figures. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.

Growing Season Fit

The zone check says longleaf pine survives winter in part of Colorado, not across all of it. Whether the season is long enough — and warm enough — is a different question.

Frost-free days

Longleaf Pine wants 270+ frost-free days; a typical Colorado site sees ~155 (NOAA Regional Climate Centers ACIS, 1991-2020) — 115 days short of what it needs. A typical Colorado season does not carry this crop to harvest outdoors, and a gap that size is not one an earlier sowing date or a faster cultivar closes; growing it here means growing it under cover.

GDD and chill-hour figures are computed from PRISM 1991-2020 monthly climate normals; frost-free days from NOAA Regional Climate Centers ACIS, 1991-2020. Each is the state median across its counties (P25/P75 span the within-state spread). Hardiness-zone range is USDA PHZM 2023.

Soil + Drainage Fit

Longleaf Pine likes near-neutral soil (pH 4-6.5). That's the common-ground band across Colorado's sandy loam and clay loam — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 4.5 and 5.5 — worth knowing before you decide whether a Colorado soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Colorado site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.

Plant pH requirements: FAO ECOCROP and USDA PLANTS, with the remaining rows from other published sources or Growable Ground compilation. Drainage: FAO ECOCROP, with the remaining rows from other published sources or Growable Ground compilation. Colorado soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

What Else to Consider for Longleaf Pine in Colorado

Zone compatibility tells you about winter cold survival — but Colorado growers also need to think about:

Low annual rainfall (7-20 inches) means irrigation is essential nearly everywhere

High altitude UV and temperature swings stress plants

Very short growing season at elevation (60-90 frost-free days above 8,000 ft)

Alkaline soils (pH 7.5-8.5) limit acid-loving plants without amendment

What to actually do about these — and the constraints that apply to every Colorado grower, not just longleaf pine — is covered on the Colorado growing guide.

Timing shifts within Colorado

Longleaf Pine needs about 270 days of frost-free season to complete its cycle. No Colorado county gives it that outdoors: even Mesa County, the state’s longest season at 209 frost-free days, falls 61 days short — so it needs transplants, a short-season variety, or covered growing.

Across Colorado’s 64 counties the frost-free season runs from 85 days in Chaffee County to 209 days in Mesa County — a spread of 124 days, which is why a single statewide planting date misleads. The median Colorado county sees 155 frost-free days, which is 115 days short of what longleaf pine needs — so on a typical Colorado parcel this is a transplant-or-protect crop, not a direct-sow one.

County last-freeze dates and frost-free day counts: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). Longleaf Pine's 270-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.

Colorado Cooperative Extension

For Colorado-specific cultivar recommendations, planting calendars, and pest pressure for longleaf pine, the canonical source is Colorado State University Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Longleaf Pine native to Colorado?

Longleaf Pine is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-07-01) does not document a native range in Colorado. It can still earn a place in a Colorado garden — the zone comparison above tells you whether it will thrive.

Looking for plants that belong here? The Colorado growing guide lists USDA-documented natives for the state.

Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.

Common Questions About Growing Longleaf Pine in Colorado

When can I plant Longleaf Pine in Colorado?

Colorado's last spring hard freeze (28°F) clears between Apr 25 and May 19, and the first fall hard freeze lands between Sep 29 and Oct 16 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Longleaf Pine, so this page does not state whether it overwinters in Colorado and publishes no fall establishment date for it — check its hardiness range against your own zone before treating it as a permanent planting.

What hardiness zone is Longleaf Pine grown in across Colorado?

Colorado spans USDA hardiness zones 3b-7b (USDA ARS PHZM 2023). Longleaf Pine carries a range of zones 7-9, so the overlap zones are where outdoor growing is most reliable.

How many frost-free days does a typical Colorado site have?

A typical Colorado site sees ~155 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Longleaf Pine needs 270+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.

Is Longleaf Pine native to Colorado?

Longleaf Pine is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-07-01) does not document a native range in Colorado. It can still earn a place in a Colorado garden — the zone comparison above tells you whether it will thrive.

How should I amend the soil for Longleaf Pine in Colorado?

Longleaf Pine prefers pH 4-6.5 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across Colorado soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.

Will Longleaf Pine actually grow on my specific land in Colorado?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores longleaf pine against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.

Free Report

Check your specific parcel in Colorado

State-level data is a sketch. Your Growable Ground report scores longleaf pine against your parcel's exact soil, sun, drainage, and frost data — not zone averages.

Three things about your lot that Colorado longleaf pine averages can't show:

Your soil pHYour frost-free days — Colorado averages 155Your sun & shade

We read public map data around Colorado — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources read at your address, not the Colorado longleaf pine average

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