Hummelstown, Pennsylvania, sits in USDA hardiness zone 7a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
The conditions favor cabbage, hazelnut, california poppy, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Hummelstown, 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 Hummelstown 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 Hummelstown — soil, climate, flood, and parcel records. How we handle your address.
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Hummelstown — the short answer
Hummelstown, Pennsylvania: USDA zone 7a, about 224 days between hard freezes, across 795 acres of town.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 31
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 10
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~224
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 795 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 7a is Hummelstown's average, not your lot's — a low corner or a tree line moves it. Against Hummelstown's 224-day season, see what your own ground reads.
Your town runs its own season
Hummelstown's own 30-year record measures about 224 days between 28°F killing freezes — 32 days longer than Dauphin County's ~192. Both are measured records, not estimates.
That gap is the whole reason a county average can mislead here. Plant against Hummelstown's ~224-day season rather than the county figure — and the sun, slope and cold-air drainage on your specific lot move it again.
NOAA Regional Climate Centers ACIS (1991–2020), 30-year daily minimum record. Both figures are measured records — this town’s own and its county’s. A town with no record of its own is absent here rather than estimated.
Soil varies lot by lot — soil types explained.
What this means for growing in Hummelstown
Each reading below is measured for Hummelstown itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredHummelstown runs about 224 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredHummelstown sits in USDA hardiness zone 7a.
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 Hummelstown is in
Hummelstown sits in the Ridge and Valley — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Hummelstown's own centroid rather than borrowed from Dauphin County.
What Grows in Hummelstown
Every plant below cleared Hummelstown's own zone 7a and its 224-day season. Each card opens that plant's Pennsylvania profile. How we score.
Is it too late to plant in Hummelstown?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Mar 3; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 31 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 10 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
Documented around Hummelstown
Spotted lanternfly documented 0 miles from Hummelstown, first recorded 2018. What to watch for.
What's on the federal record near Hummelstown
Closest first, within ~10 miles of Hummelstown. Listing isn't leaking, and distance isn't exposure.
- ENGLES GARAGEUnderground Storage Tanks · 100 ft
- SOPKO AUTO SALESUnderground Storage Tanks · 200 ft
- A1 AUTO SUPPLIESUnderground Storage Tanks · 350 ft
- TRINITY UNITED METH CHUnderground Storage Tanks · 350 ft
- NYE ELEM SCHUnderground Storage Tanks · 750 ft
- DENISON LPUnderground Storage Tanks · 1400 ft
- HUMMELSTOWN OFCUnderground Storage Tanks · 1500 ft
- POSIES INCBrownfields · 1600 ft
- HUMMELSTOWN BORO DAUPHIN CNTYUnderground Storage Tanks · 1700 ft
- HESTECO MFGUnderground Storage Tanks · 1800 ft
- J & H EXXONUnderground Storage Tanks · 2000 ft
- PENNSY SUPPLY INC/FIDDLERS ELBOW NORTH QUARRYToxics Release Inventory · 2100 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Hummelstown'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 Hummelstown.
Sources Checked
within ~10 miles of Hummelstown
Severity Distribution
within ~10 miles of Hummelstown
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Hummelstown, CAFO runs higher than the national average — 15 sites within ~10 miles of Hummelstown. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Check your specific parcel in Hummelstown
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 Hummelstown average
Your land is one point inside Hummelstown
Everything above resolves to Hummelstown as a whole — and this is a town whose own 30-year record already runs a season its county’s does not. Your parcel sits at one point inside even that. 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 Hummelstown Average
Hummelstown Average
- ●USDA Zones 7a, averaged across Hummelstown
- ●One soil character for all of Hummelstown
- ●Frost dates read at Hummelstown's scale: Mar 31 to Nov 10
YOUR Parcel
- ✓Your exact zone, not Hummelstown's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Hummelstown
Pull a site-specific report for your exact address in Hummelstown, Pennsylvania — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Hummelstown averages can't show:
We read public map data around Hummelstown — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Hummelstown average
How we know this about Hummelstown
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 Hummelstown’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 Hummelstown
When does frost risk typically end in Hummelstown?
The last hard freeze (28°F) in Hummelstown typically lands around Mar 31, 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 Apr 21.
When is the first frost in Hummelstown?
The first hard freeze (28°F) in Hummelstown typically arrives around Nov 10, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 27, so the watching starts about Oct 11 — about 224 days after the spring freeze cleared.
How long is the growing season in Hummelstown?
Measured between 28°F hard freezes, Hummelstown sees about 224 frost-free days — roughly Mar 31 through Nov 10, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 21 to Oct 27, about 189 days.
Is the soil safe to grow vegetables in Hummelstown?
The federal record around Hummelstown is a meaningful one — 1,594 documented sites, mostly Underground Storage Tanks entries (941), the nearest Underground Storage Tanks record under a tenth of a mile 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 I protect my plants from frost in Hummelstown?
From about Oct 11 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 10 (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 10. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Hummelstown's scale — its 7a band and its 224-day season. Your yard writes its own version of Hummelstown'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 Hummelstown’s own scale
7 of the readings below were taken at Hummelstown's own scale — its own ~224-day season between 28°F freezes, the 795 acres it covers and 1,594 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Hummelstown's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Hummelstown's own 28°F hard-freeze dates, about Mar 31 and Nov 10 and the ~224-day span between themNOAA 1991–2020 Climate Normals
- 1,594 documented contamination sites on the federal record near Hummelstown, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Hummelstown's boundary and the 795 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~224-day seasonGrowable Ground crop-matching engine
- The ecoregion at Hummelstown's own centroid, the Ridge and ValleyUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Hummelstownlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Hummelstown's 795 acres read through its county's SSURGO summaryfrom Dauphin County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Dauphin County
- The growing challenges every Pennsylvania grower plans around — written at state scale, so they stay on the state guidefrom Pennsylvania
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Dauphin County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Hummelstown's 795 acreswhy one lot differs from the next →
- Which side of Hummelstown you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 795 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record under a tenth of a mile 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 Hummelstown-wide figureread your own land →
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