Round Mountain, Texas, sits in USDA hardiness zone 8b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Growers here do well with cabbage, fig, california poppy, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Round Mountain, 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 Round Mountain 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 Round Mountain — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Round Mountain — the short answer
Round Mountain, Texas: USDA zone 8b, about 265 days between hard freezes, across 1K acres of town.
- USDA zone
- 8b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 1
- Blanco County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Nov 21
- Blanco County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~265
- Blanco County normal — NOAA 1991–2020, nearest to this town
- Town area
- 1K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. No 30-year normal resolves at this town’s own centroid, so the hard-freeze dates are Blanco County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 8b is Round Mountain's average, not your lot's — a low corner or a tree line moves it. Against Round Mountain's 265-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Round Mountain
Each reading below is measured for Round Mountain itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsRound Mountain runs about 265 days between hard freezes (read from Blanco County, the closest normal to Round Mountain) — close to year-round growing.
Frost is rarely the limit here; winter plantings are as real as summer ones, and the harder question is which crops shrug off the summer heat.
Grow cool-season crops through the mild winter, and choose heat-tolerant varieties for the summer beds.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredRound Mountain sits in USDA hardiness zone 8b.
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 Round Mountain is in
Round Mountain sits in the Edwards Plateau — EPA Level III, inside the wider Great Plains. That is read at Round Mountain's own centroid rather than borrowed from Blanco County.
What Grows in Round Mountain
Every plant below cleared Round Mountain's own zone 8b and its 265-day season. Each card opens that plant's Texas profile. How we score.
Is it too late to plant in Round Mountain?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Feb 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 1 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 21 — long-season crops need about 90 days of runway, quick greens only 30. Here the calendar nearly circles: cool-season crops take the winter shift, and the next window is always close.
What's on the federal record near Round Mountain
Closest first, within ~10 miles of Round Mountain. Listing isn't leaking, and distance isn't exposure.
- BIGS 108Underground Storage Tanks · 2.3 mi
- Scott Klett ProspectMining · 7.1 mi
- TXDOT JOHNSON CITY MAINTENANCE FACILITYUnderground Storage Tanks · 7.7 mi
- 7-ELEVEN STORE 40575Underground Storage Tanks · 7.9 mi
- DIXIE QUICK STOPUnderground Storage Tanks · 8.0 mi
- MAX E MART 13Underground Storage Tanks · 8.5 mi
- AZ-57-45-927Nitrate · 8.5 mi
- ALS GROCERYUnderground Storage Tanks · 8.6 mi
- JOHNSON CITY CHEVRONUnderground Storage Tanks · 8.6 mi
- KWIK CHEK 54Underground Storage Tanks · 8.6 mi
- LYNDON B JOHNSON NATL HISTORICAL PARKBrownfields · 8.7 mi
- BIG DADDYSUnderground Storage Tanks · 8.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Round Mountain'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 Round Mountain.
Total Sites
46
within ~10 miles of Round Mountain
Risk Level
Moderate
Highest-severity
1 mining site (prospects, none worked)
Sources Checked
within ~10 miles of Round Mountain
Severity Distribution
within ~10 miles of Round Mountain
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Round Mountain, Underground Storage Tanks runs higher than the national average — 37 sites within ~10 miles of Round Mountain. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Round Mountain
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 Round Mountain average
Your land is one point inside Round Mountain
Everything above resolves to Round Mountain as a whole — one PHZM band, read across 1K acres, with hard-freeze dates borrowed from Blanco County’s record because no 30-year normal resolves at this town’s own centroid. 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 Round Mountain Average
Round Mountain Average
- ●USDA Zones 8b, averaged across Round Mountain
- ●One soil character for all of Round Mountain
- ●Frost dates read at Round Mountain's scale: Mar 1 to Nov 21
YOUR Parcel
- ✓Your exact zone, not Round Mountain's 8b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Round Mountain
Pull a site-specific report for your exact address in Round Mountain, Texas — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Round Mountain averages can't show:
We read public map data around Round Mountain — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Round Mountain average
How we know this about Round Mountain
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 Blanco County’s record, because none resolves here; 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 Round Mountain
When does frost risk typically end in Round Mountain?
The last hard freeze (28°F) in Round Mountain typically lands around Mar 1, 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 Mar 22.
When is the first frost in Round Mountain?
The first hard freeze (28°F) in Round Mountain typically arrives around Nov 21, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 7, so the watching starts about Oct 22 — about 265 days after the spring freeze cleared.
How long is the growing season in Round Mountain?
Measured between 28°F hard freezes, Round Mountain sees about 265 frost-free days — roughly Mar 1 through Nov 21, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 22 to Nov 7, about 230 days.
Is the soil safe to grow vegetables in Round Mountain?
The federal record around Round Mountain shows 46 documented sites, mostly Underground Storage Tanks entries (37), the nearest Underground Storage Tanks record about 2.3 miles out — a typical footprint for a growing area, and proximity to a documented site is information, not a diagnosis of any one yard. It's worth seeing which recorded sites sit closest to where you grow, and testing the soil before new food beds near any of them.
How do I protect my plants from frost in Round Mountain?
From about Oct 22 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Nov 21 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Nov 21. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Round Mountain's scale — its 8b band and its 265-day season. Your yard writes its own version of Round Mountain'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 Round Mountain’s own scale
5 of the readings below were taken at Round Mountain's own scale — the 1,475 acres it covers and 46 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Round Mountain's own USDA hardiness band, zones 8bUSDA PHZM 2023
- 46 documented contamination sites on the federal record near Round Mountain, the closest Underground Storage Tanks record about 2.3 miles out from the town centreFederal environmental registers
- Round Mountain's boundary and the 1,475 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8b and a ~265-day seasonGrowable Ground crop-matching engine
- The ecoregion at Round Mountain's own centroid, the Edwards PlateauUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Round Mountain has no normal of its own, so its county's is the closest measured readfrom Blanco County
- Soil character — no town-scale survey exists, so Round Mountain's 1,475 acres read through its county's SSURGO summaryfrom Blanco County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Blanco County
- The growing challenges every Texas grower plans around — written at state scale, so they stay on the state guidefrom Texas
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Blanco County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Round Mountain's 1,475 acreswhy one lot differs from the next →
- Which side of Round Mountain you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,475 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 2.3 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 Round Mountain-wide figureread your own land →