Smiths Ferry, Idaho, sits in USDA hardiness zone 5b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Expect cabbage, cranberry, lavender, and collard greens to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Even in Smiths Ferry, 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 Smiths Ferry 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 Smiths Ferry — soil, climate, flood, and parcel records. How we handle your address.
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Smiths Ferry — the short answer
Smiths Ferry, Idaho: USDA zone 5b, about 139 days between hard freezes, across 1K acres of town.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 16
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 2
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~139
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 1K 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 5b is Smiths Ferry's average, not your lot's — a low corner or a tree line moves it. Against Smiths Ferry's 139-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Smiths Ferry
Each reading below is measured for Smiths Ferry itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSmiths Ferry runs about 139 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
MeasuredSmiths Ferry sits in USDA hardiness zone 5b.
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 Smiths Ferry is in
Smiths Ferry sits in the Idaho Batholith — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Smiths Ferry's own centroid rather than borrowed from Valley County.
What Grows in Smiths Ferry
Every plant below cleared Smiths Ferry's own zone 5b and its 139-day season. Each card opens that plant's Idaho profile. How we score.
Is it too late to plant in Smiths Ferry?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Apr 18; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 16 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 2 — long-season crops need about 90 days of runway, quick greens only 30. In a season this compact, fast finishers and cold-hardy greens do the late work, and garlic tucked in before the freeze repays you next summer.
What's on the federal record near Smiths Ferry
Closest first, within ~10 miles of Smiths Ferry. Listing isn't leaking, and distance isn't exposure.
- SOUTHERN IDAHO TIMBER PROTECTIVE ASSOCIATIONUnderground Storage Tanks · 0.5 mi
- COUGAR MOUNTAIN LODGEUnderground Storage Tanks · 0.6 mi
- IDAHO TRANSPORTATION DEPTUnderground Storage Tanks · 1.7 mi
- SMITHS FERRY WORK STATIONUnderground Storage Tanks · 1.7 mi
- 11N 03E 01DDC1Nitrate · 2.0 mi
- 12N 04E 30DCA1Nitrate · 3.8 mi
- B-MineMining · 7.5 mi
- 12N 04E 04CBC1Nitrate · 8.0 mi
- US WEST (9)Underground Storage Tanks · 8.2 mi
- US DOT FAA RADAR UNIT CASCADEBrownfields · 8.2 mi
- 13N 04E 32DBB1Nitrate · 8.8 mi
- 13N 04E 32ACC1Nitrate · 8.9 mi
1 more site is on the record inside the same radius. See them on the map
Measured from Smiths Ferry'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 Smiths Ferry.
Total Sites
18
within ~10 miles of Smiths Ferry
Risk Level
Low
Highest-severity
2 mining sites (prospects, none worked)
Sources Checked
within ~10 miles of Smiths Ferry
Severity Distribution
within ~10 miles of Smiths Ferry
Highest-Severity Sites
Know Before You Grow
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Mine waste leaches heavy metals. Test for lead, arsenic and cadmium before growing food here.
Check your specific parcel in Smiths Ferry
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 Smiths Ferry average
Your land is one point inside Smiths Ferry
Everything above resolves to Smiths Ferry as a whole — one PHZM band and one 28°F frost record, read across 1K 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 Smiths Ferry Average
Smiths Ferry Average
- ●USDA Zones 5b, averaged across Smiths Ferry
- ●One soil character for all of Smiths Ferry
- ●Frost dates read at Smiths Ferry's scale: May 16 to Oct 2
YOUR Parcel
- ✓Your exact zone, not Smiths Ferry's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Smiths Ferry
Pull a site-specific report for your exact address in Smiths Ferry, Idaho — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Smiths Ferry averages can't show:
We read public map data around Smiths Ferry — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Smiths Ferry average
How we know this about Smiths Ferry
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 Smiths Ferry’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 Smiths Ferry
When does frost risk typically end in Smiths Ferry?
The last hard freeze (28°F) in Smiths Ferry typically lands around May 16, 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 6.
When is the first frost in Smiths Ferry?
The first hard freeze (28°F) in Smiths Ferry typically arrives around Oct 2, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 18, so the watching starts about Sep 2 — about 139 days after the spring freeze cleared.
How long is the growing season in Smiths Ferry?
Measured between 28°F hard freezes, Smiths Ferry sees about 139 frost-free days — roughly May 16 through Oct 2, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 6 to Sep 18, about 104 days.
Is the soil safe to grow vegetables in Smiths Ferry?
The federal record around Smiths Ferry is light — 18 documented sites across the 9 federal source types we checked, mostly Nitrate entries (10), the nearest Underground Storage Tanks record about 0.5 miles out — and proximity to a documented site is information, not a diagnosis of any one yard. Growing food here starts from a strong position; a soil test before new food beds settles any site-specific question.
How do gardeners stretch the season in Smiths Ferry?
With about 139 frost-free days between hard freezes, Smiths Ferry 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 167 to 195 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 16 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Smiths Ferry's scale — its 5b band and its 139-day season. Your yard writes its own version of Smiths Ferry'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 Smiths Ferry’s own scale
6 of the readings below were taken at Smiths Ferry's own scale — its own ~139-day season between 28°F freezes, the 1,183 acres it covers and 18 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Smiths Ferry's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Smiths Ferry's own 28°F hard-freeze dates, about May 16 and Oct 2 and the ~139-day span between themNOAA 1991–2020 Climate Normals
- 18 documented contamination sites on the federal record near Smiths Ferry, the closest Underground Storage Tanks record about 0.5 miles out from the town centreFederal environmental registers
- Smiths Ferry's boundary and the 1,183 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~139-day seasonGrowable Ground crop-matching engine
- The ecoregion at Smiths Ferry's own centroid, the Idaho BatholithUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Smiths Ferry's 1,183 acres read through its county's SSURGO summaryfrom Valley County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Valley County
- The growing challenges every Idaho grower plans around — written at state scale, so they stay on the state guidefrom Idaho
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Valley County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Smiths Ferry's 1,183 acreswhy one lot differs from the next →
- Which side of Smiths Ferry you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,183 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.5 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 Smiths Ferry-wide figureread your own land →
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