Muraina grass (Ischaemum rugosum), photographi

Can I Grow Muraina Grass in Colorado?

USDA Zones 3b-7b · Plant zone range 9-12

Unlikely — Zone Mismatch

Muraina grass (zones 9-12) does not overlap with Colorado's zone range (3b-7b). Growing outdoors is unlikely without significant protection.

2 zones short — what would close it

Muraina Grass is hardy to zone 9, and the warmest ground in Colorado is zone 7 — 2 zones short. Planted in open ground it will not survive a Colorado winter. To grow it here, grow muraina grass in an earth-sheltered greenhouse — its modeled 2.5-zone lift covers this gap.

An earth-sheltered greenhouse is the lift this needs. How a greenhouse changes what you can grow →

Zone math from 9-12 (plant) against 3-7 (Colorado). Lift modeled by crop_engine.GREENHOUSE_ZONE_MODIFIER_BY_SUBTYPE['earth_sheltered'] (+2.5 zones) via api/fast_sections.py Unlock Engine v2.

Muraina Grass in Colorado — the short answer

Muraina Grass in Colorado: hardy in zones 9–12, full sun, against a state median of ~155 frost-free days.

Plant zones
9-12
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.

Score your parcel · free

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 muraina grass against your parcel's actual hardiness, soil, and sun.

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

No card required · your full report in seconds

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 muraina grass 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 Muraina Grass Stands in Colorado

Muraina Grass is rated for zones 912 — a cold floor USDA puts at 20 to 30°F. No Colorado county sits inside it, so in open ground this is a grown-under-cover plant here rather than a bed plant — which is a statement about Colorado winters, not about muraina grass.

Below the zone 9 floor

64 counties

3 of 64 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.

Zone Comparison

Muraina Grass Needs

  • USDA Zones: 9-12
  • Frost-Free Days: 175+
  • Sun: Full Sun

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 9-12)

9a
12b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 4.07.0

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 Muraina Grass 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 muraina grass, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether muraina grass 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.

Timing tuned to sub-state frost dates — Chaffee County, not the statewide average.

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 muraina grass does not survive a Colorado winter in the ground. The season figures below measure a different question — whether it could finish a season here at all — and they only bear on Colorado under protection.

Frost-free days

Muraina Grass wants 175+ frost-free days; a typical Colorado site sees ~155 (NOAA Regional Climate Centers ACIS, 1991-2020) — 20 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

Muraina Grass tolerates a wide pH range (pH 4-7) — 3 units, acid ground through alkaline — so soil acidity is rarely what limits it in Colorado. A soil test is still worth having, but for what else it tells you about this site, not to clear this plant. 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 requirement: poorly (saturated >50% of year). A soil-survey lookup (NRCS SSURGO) flags whether your specific site matches.

Your land, not the state average

Colorado's soils run mostly loam, but SSURGO maps the series, texture, and drainage under your exact parcel. Muraina Grass needs about 19 inches of workable depth, so it is that horizon — not the surface — you are testing for. That map unit, not the state average, decides how muraina grass performs.

Check your parcel → Source: USDA NRCS SSURGO.

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.

Before you plant muraina grass for food

Anything you grow to eat takes up what is in the ground it grows in, so what is on record near you is worth knowing before muraina grass goes in. What follows is Colorado’s documented federal record at state scale — a screening signal, not a soil test, and not a statement about any one lot.

Safe to Grow Here?

What the federal record shows across Colorado — and how to grow with it.

Federal record: High

We checked the federal record across Colorado29,759 documented sites across 8 of the 9 source types we track.

The most significant on record: 281 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.

Colorado carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.

Know before you grow — the guide

Sources Checked

across Colorado

Severity Distribution

across Colorado

High3,479Moderate11,495Low14,785

Highest-Severity Sites

Mining Sites · Past Producer
Mining Sites · Past Producer
Mining Sites · Past Producer
Superfund · Superfund NPL
PFAS Sampling · PFAS Detected

A note from Gnorman

What an experienced grower watches for around here

In and around Colorado, Mining runs higher than the national average — 5,049 sites across Colorado. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.

Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.

Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.

Sources: EPA, USGS1.8M documented sites tracked nationwide across 9 federal source types.

What Else to Consider for Muraina Grass 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

Growing muraina grass here specifically

Muraina Grass needs pH 4.0–7.0; Colorado's dominant loam soils may or may not deliver that, so your parcel's SSURGO map unit is the real test.

Start with a soil test on your own ground and adjust pH and texture to fit muraina grass's 4.0–7.0 range. How to handle it →

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

Timing shifts within Colorado

Colorado isn't one climate. In Chaffee County, the last hard freeze (28°F) holds until about Jun 12 — roughly 38 days later than the recorded state median — so plant muraina grass to your county's window, not the statewide date.

Muraina Grass needs about 175 days of frost-free season to complete its cycle. 16 of Colorado’s 64 counties give it that outright. The tightest that does is Phillips County at 176 frost-free days — 1 to spare. Below that line you are transplanting or extending the season, not direct-sowing.

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 20 days short of what muraina grass 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"). Muraina Grass's 175-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 muraina grass, the canonical source is Colorado State University Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Muraina Grass native to Colorado?

No — the USDA PLANTS Database lists Muraina Grass as introduced rather than native in the Lower 48, so it is not part of Colorado's native flora. It grows here as a garden plant; pairing it with a few Colorado natives keeps local pollinators fed too.

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 Muraina Grass in Colorado

When can I plant Muraina Grass 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 Muraina Grass, 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 Muraina Grass grown in across Colorado?

Colorado spans USDA hardiness zones 3b-7b (USDA ARS PHZM 2023). Muraina Grass carries a range of zones 9-12, 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). Muraina Grass needs 175+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date. In cooler counties like Chaffee, the freeze-free season runs shorter than the state average, so verify your own county's window.

Is Muraina Grass native to Colorado?

No — the USDA PLANTS Database lists Muraina Grass as introduced rather than native in the Lower 48, so it is not part of Colorado's native flora. It grows here as a garden plant; pairing it with a few Colorado natives keeps local pollinators fed too.

How should I amend the soil for Muraina Grass in Colorado?

Muraina Grass tolerates pH 4-7 and poorly (saturated >50% of year) drainage (FAO ECOCROP). That is a 3-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Colorado site — amend for drainage and organic matter first.

Will Muraina Grass actually grow on my specific land in Colorado?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores muraina grass 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 muraina grass against your parcel's exact soil, sun, drainage, and frost data — not zone averages.

Three things about your lot that Colorado muraina grass 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 muraina grass average

Analysis by the Growable Ground research team, grounded in USDA PLANTS, USDA NRCS SSURGO, NOAA Climate Normals (1991-2020), and named Cooperative Extension sources. How we know →

Cite this dataset

Kirchick, M. (2026). Growable Ground Plant Database [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21435643

Licensed CC BY-NC 4.0. DOI 10.5281/zenodo.21435643

Last updated: