Phippsburg, Colorado, sits in USDA hardiness zone 4b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Well-matched crops include okra, cranberry, cilantro, and zucchini, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Even in Phippsburg, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Phippsburg lot. Enter your address and we'll score 1,086 plants against your land's actual soil, sun, and frost.
We read public map data around Phippsburg — soil, climate, flood, and parcel records. How we handle your address.
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Phippsburg — the short answer
Phippsburg, Colorado: USDA zone 4b, about 119 days between hard freezes, across 759 acres of town.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 27
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Sep 23
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~119
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 759 acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.
Hardiness Zone Range
Zone 4b is Phippsburg's average, not your lot's — a low corner or a tree line moves it. Against Phippsburg's 119-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Phippsburg
Each reading below is measured for Phippsburg itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredPhippsburg runs about 119 days between hard freezes — a short growing season.
Long-maturing crops like melons, sweet potatoes, and winter squash can run out of runway before the first hard freeze, ripening late or not at all.
Lead with fast-maturing varieties, and stretch the season on both ends with cold frames, low tunnels, or a greenhouse.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredPhippsburg sits in USDA hardiness zone 4b.
The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.
Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.
USDA PHZM 2023
The kind of country Phippsburg is in
Phippsburg sits in the Southern Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Phippsburg's own centroid rather than borrowed from Routt County.
What Grows in Phippsburg
Every plant below cleared Phippsburg's own zone 4b and its 119-day season. Each card opens that plant's Colorado profile. How we score.
Is it too late to plant in Phippsburg?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Apr 29; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 27 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 23 — long-season crops need about 90 days of runway, quick greens only 30. Even here the calendar’s edges hold value: thirty-day greens late in the window, then garlic and a rested bed for spring.
What's on the federal record near Phippsburg
Closest first, within ~10 miles of Phippsburg. Listing isn't leaking, and distance isn't exposure.
- Phippsburg YardUnderground Storage Tanks · 2200 ft
- Phippsburg GarageUnderground Storage Tanks · 2500 ft
- PHIPPSBURG WASTE DUMPSuperfund · 0.8 mi
- P-burg MarketUnderground Storage Tanks · 1.0 mi
- Maneotis SinclairUnderground Storage Tanks · 2.3 mi
- Town Of Oak Creek - MaintenanceUnderground Storage Tanks · 2.8 mi
- Space Station - Oak CreekUnderground Storage Tanks · 3.1 mi
- J Woods Oil & GasUnderground Storage Tanks · 3.2 mi
- Routt County Road & Bridge Dist 1Underground Storage Tanks · 3.2 mi
- BLM-OAK CREEK LANDFILL (ROUTT COUNTY)Superfund · 5.4 mi
- CDOT Yampa Maintenance YardUnderground Storage Tanks · 5.7 mi
- Edward FarringtonUnderground Storage Tanks · 5.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Phippsburg's center, not your beds. Run your own address for what's upwind of you specifically.
Environmental Intelligence
The counts behind that headline — every source type on the record near Phippsburg.
Total Sites
22
within ~10 miles of Phippsburg
Risk Level
Elevated
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Phippsburg
Severity Distribution
within ~10 miles of Phippsburg
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
- •A Superfund listing means federally documented contamination. Test soil and water before planting edibles nearby.
Check your specific parcel in Phippsburg
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.
25+ data sources read at your address, not the Phippsburg average
Your land is one point inside Phippsburg
Everything above resolves to Phippsburg as a whole — one PHZM band and one 28°F frost record, read across 759 acres. Your parcel is one point inside that footprint. Slope, tree cover, a low spot that pools cold air, and what is in the soil are all resolved at the address, and none of them are visible at town scale. That is the honest boundary of this page, and the reason the next step is a reading of your own ground rather than a better local average.
Your Lot vs the Phippsburg Average
Phippsburg Average
- ●USDA Zones 4b, averaged across Phippsburg
- ●One soil character for all of Phippsburg
- ●Frost dates read at Phippsburg's scale: May 27 to Sep 23
YOUR Parcel
- ✓Your exact zone, not Phippsburg's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Phippsburg
Pull a site-specific report for your exact address in Phippsburg, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Phippsburg averages can't show:
We read public map data around Phippsburg — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Phippsburg average
How we know this about Phippsburg
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Phippsburg’s own record; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at town grain anywhere on this page — there is no town-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Phippsburg
When does frost risk typically end in Phippsburg?
The last hard freeze (28°F) in Phippsburg typically lands around May 27, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about Jun 17.
When is the first frost in Phippsburg?
The first hard freeze (28°F) in Phippsburg typically arrives around Sep 23, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 9, so the watching starts about Aug 24 — about 119 days after the spring freeze cleared.
How long is the growing season in Phippsburg?
Measured between 28°F hard freezes, Phippsburg sees about 119 frost-free days — roughly May 27 through Sep 23, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 17 to Sep 9, about 84 days.
Is the soil safe to grow vegetables in Phippsburg?
The federal record around Phippsburg is a meaningful one — 22 documented sites, mostly Underground Storage Tanks entries (17), the nearest Underground Storage Tanks record about 0.4 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do gardeners stretch the season in Phippsburg?
With about 119 frost-free days between hard freezes, Phippsburg rewards the classic extension moves: floating row cover buys roughly two to four extra weeks at each shoulder — on this season that is a working window nearer 147 to 175 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 27 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Phippsburg's scale — its 4b band and its 119-day season. Your yard writes its own version of Phippsburg's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Phippsburg’s own scale
6 of the readings below were taken at Phippsburg's own scale — its own ~119-day season between 28°F freezes, the 759 acres it covers and 22 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Phippsburg's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Phippsburg's own 28°F hard-freeze dates, about May 27 and Sep 23 and the ~119-day span between themNOAA 1991–2020 Climate Normals
- 22 documented contamination sites on the federal record near Phippsburg, the closest Underground Storage Tanks record about 0.4 miles out from the town centreFederal environmental registers
- Phippsburg's boundary and the 759 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~119-day seasonGrowable Ground crop-matching engine
- The ecoregion at Phippsburg's own centroid, the Southern RockiesUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Phippsburg's 759 acres read through its county's SSURGO summaryfrom Routt County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Routt County
- The growing challenges every Colorado grower plans around — written at state scale, so they stay on the state guidefrom Colorado
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Routt County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Phippsburg's 759 acreswhy one lot differs from the next →
- Which side of Phippsburg you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 759 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.4 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Phippsburg-wide figureread your own land →