Penryn, California, sits in USDA hardiness zones 6a-7b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Well-matched crops include tomato, grape, fig, and california poppy, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Even in Penryn, 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 Penryn lot. Enter your address and we'll score 1,112 plants against your land's actual soil, sun, and frost.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Quick Facts
USDA Zones
6a-7b
Last Frost (state avg.)
Jan 15 - May 15
First Hard Freeze (28°F)
Dec 10
Placer County normal — light frosts arrive a few weeks earlier
Town Area
1K acres
Hardiness Zone Range
Growing Season (statewide frost window)
Zone maps are averages across Penryn. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
Soil varies lot by lot — soil types explained.
What Grows in Penryn
Plants matched to Penryn's USDA zones 6a-7b — each links to its full growing profile.
Growing Challenges in California
What an experienced grower plans around here — each one has a move.
Drought is a persistent challenge — irrigation is essential in most regions
Design the water system before the plants: drip lines plus a thick mulch layer run a full garden on surprisingly little water.
Wildfire risk affects rural and foothill properties
Keep plantings low, lean, and well-watered near structures — your extension office publishes firewise landscaping guides for your county.
Adobe clay soils in valleys drain poorly without amendment
Work in compost over seasons, or skip the fight with a raised bed — adobe's nutrients are excellent once drainage is solved.
Wide climate variation means plant selection is highly location-specific
Zones run 5a to 11a in one state — check your exact zone before trusting any statewide planting list.
For cultivar selection, pest pressure, and planting-time guidance specific to California, the UC Agriculture and Natural Resources is the authoritative local source.
Environmental Intelligence
Understanding what's nearby helps you make informed decisions about where and how to grow.
Sources Checked
within ~10 miles of Penryn
Severity Distribution
within ~10 miles of Penryn
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Penryn, two things run higher than the national average — Brownfields (1,261 sites) and Mining (115 sites). That's not a problem with your land — it's information about it.
Brownfields: Brownfield sites are former commercial or industrial properties where legacy soil contamination (heavy metals, PAHs, petroleum compounds) may persist.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Check EPA brownfield remediation status — many sites have completed cleanup with institutional controls.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Check your specific parcel in Penryn
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,112 plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Your Specific Parcel Matters
Penryn Average
- ●USDA Zones 6a-7b
- ●Generic soil type for the area
- ●State-average frost dates
YOUR Parcel
- ✓Your exact hardiness zone
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Penryn
Pull a site-specific report for your exact address in Penryn, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Key Growing Facts for Penryn, California
- USDA Hardiness Zones: 6a-7b (USDA PHZM 2023)
- Last Spring Frost (state avg.): Jan 15 - May 15 (NOAA 30-Year Climate Normals)
- First Hard Freeze (28°F): Dec 10 (placer county normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
- Land Area: 1K acres (US Census TIGER 2025)
Zone data: USDA ARS Plant Hardiness Zone Map 2023. Climate data: NOAA NCEI. Boundaries: US Census TIGER/Line 2025.
Frequently Asked Questions
What hardiness zone is Penryn, California?
Penryn sits in USDA hardiness zones 6a-7b, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.
When does frost risk typically end in Penryn?
Penryn follows California's statewide frost window: last spring frost around Jan 15 - May 15 and first fall frost around Oct 1 - Dec 31, per NOAA 30-year climate normals (1991–2020). Frost dates shift with elevation and local microclimate, so watch your own site's cold pockets.
When is the first frost in Penryn?
The first hard freeze (28°F) in Penryn typically arrives around Dec 10, per NOAA 1991–2020 climate normals — the point most tender summer crops finish. Lighter frosts usually reach a couple of weeks earlier, so watch the forecast from late summer on and harvest or cover tender plants before the first cold night.
What vegetables grow in Penryn?
Penryn's zones 6a-7b support a wide range — strong performers include Tomato, Grape, Fig, California Poppy, and Almond. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.
Which hardiness zone is Penryn, really?
Officially, Penryn sits in USDA zones 6a-7b (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,112 plants against what's actually there.
Is the soil safe to grow vegetables in Penryn?
The federal record around Penryn runs heavier than most — 1,554 documented sites — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
How do I protect my plants from frost in Penryn?
As the season closes around the first 28°F hard freeze near Dec 10 (NOAA 1991–2020 climate normals), a few moves buy time: cover tender plants with floating row cover or an old sheet on still, clear nights, water the soil the afternoon before a freeze so it holds warmth overnight, and harvest frost-tender crops like tomatoes, peppers, and basil before the first hard night. Hardy greens and root crops shrug off light frost and often sweeten after it, so leave them in.
Everything on this page is a Penryn average. Your yard writes its own version — we read soil, sun, drainage, and frost at your exact address. Try it for 14 days — no card required.
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