Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for Round Top, TX

Round Top, TX is in USDA zone 9a across its 2 ZIP codes. The median last spring frost is March 4 and the first fall frost November 25.

Round Top on the zone map

Outlined: its 1 ZIP code areas · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone9a20 to 25 °F

ZIP codes2

Last frostMar 4

First frostNov 25

Growing season267 days

9a 2 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Round Top, TX…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Round Top, TX

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostMarch 4median — 50% chance of a later frost

Safe for tender plantsMarch 25only 10% chance of frost after

First fall frostNovember 25median — 10% chance by Nov 5

Growing season267 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 15 and returns around December 10.

From the NOAA station La Grange, TX, elevation 358 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in Round Top

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Jan 21 – Feb 4

SpinachSow outdoors · Jan 21 – Feb 11

Broccoli, cabbageStart indoors · Dec 24 – Jan 7

Broccoli, cabbageTransplant · Feb 11 – Feb 25

Onion setsPlant outdoors · Feb 4 – Feb 18

PotatoesPlant outdoors · Feb 11 – Feb 25

LettuceSow outdoors · Feb 4 – Feb 18

Carrots, beetsSow outdoors · Feb 11 – Feb 25

TomatoesStart indoors · Jan 7 – Jan 21

TomatoesTransplant · Mar 11 – Mar 25

Peppers, eggplantStart indoors · Dec 24 – Jan 7

Peppers, eggplantTransplant · Mar 18 – Apr 1

BeansSow outdoors · Mar 11 – Mar 25

Sweet cornSow outdoors · Mar 11 – Mar 25

Cucumbers, squashSow outdoors · Mar 11 – Mar 25

Fall lettuce, spinachSow outdoors · Sep 30 – Oct 14

GarlicPlant cloves · Nov 11 – Dec 16

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 4) and first fall frost (Nov 25) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 78961 came on Jan 15 — 10 days earlier than the 1991–2020 average (Jan 25).

average
Jan 252026
Jan 15

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 9a in Texas

640 plants native to the lower 48 states, recorded in Texas, and rated by the USDA to survive 20 °F or colder — the bottom of zone 9a. Each links to its USDA PLANTS profile.

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Round Top, TX.

Soil in Round Top, TX

The soil mapped at the center of ZIP 78961 is Carbengle — sandy clay loam, well drained.

TextureSandy clay loamholds water and nutrients; slow to drain and warm up

pH8.2alkaline; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2%moderate

Hydrologic groupCwater soaks in slowly

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Carbengle sandy clay loam, 3 to 5 percent slopes.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 78961; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Round Top, TX

Summer high97 °Faverage high, July

Winter low40 °Faverage low, January

Hot days121days a year at 90 °F or more

Freezing nights19nights a year at 32 °F or less

Growing degree days7,228base 50 °F — the season’s usable heat

Longest day14 h 05 mindaylight on June 21

Shortest day10 h 12 mindaylight on December 21

Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb

Precipitation42.2 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: La Grange, TX (15 mi away); precipitation: Round Top 0.2 W, TX (within 1 mile). Daylight is calculated from latitude.

ZIP codes in Round Top

Texas planting zones →

Questions about Round Top

What planting zone is Round Top, TX?

Round Top, TX is in USDA hardiness zone 9a on the 2023 map (9a: 20 to 25 °F).

When is the last frost in Round Top, TX?

The median last spring frost is March 4 and the median first fall frost is November 25 (NOAA 1991–2020 normals, La Grange station).

When can I plant a garden in Round Top, TX?

Cool-season crops like peas and spinach go in around Jan 21 – Feb 11; tomatoes, peppers, beans and squash after about Mar 11, once frost risk has passed.

What kind of onions grow in Round Top, TX?

Short-day onions: the longest day is 14 h 05 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.

How much rain and snow does Round Top, TX get?

About 42.2 inches of precipitation a year (NOAA 1991–2020 normals).