Malta, Idaho, sits in USDA hardiness zones 5a-6b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Growers here do well with potato, apple, hop, and cherry — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Malta, 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 Malta 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.
No card required · your full report in seconds
Quick Facts
USDA Zones
5a-6b
Last Hard Freeze (28°F)
Apr 23
Town normal — light frosts run a few weeks later
First Hard Freeze (28°F)
Oct 17
Town normal — light frosts arrive a few weeks earlier
City Area
883 acres
Hardiness Zone Range
Zone maps are averages across Malta. 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 Malta
Plants matched to Malta's USDA zones 5a-6b — each links to its full growing profile.





Is it too late to plant in Malta?
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 26; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 23 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 17 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.

Growing Challenges in Idaho
What an experienced grower plans around here — each one has a move.

Short growing season at higher elevations
At elevation, fast varieties plus a cold frame or low tunnel reliably buy back the weeks the calendar withholds.

Arid conditions require irrigation in most of the state
Drip irrigation and deep mulch are the arid-country baseline — set the water system before the plants.

Cold winter snaps can reach -30F in mountain valleys
Plant perennials for your real zone, not an optimistic one — a -30°F night finds every zone-pushed plant.
For cultivar selection, pest pressure, and planting-time guidance specific to Idaho, the University of Idaho Extension 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 Malta
Severity Distribution
within ~10 miles of Malta
Highest-Severity Sites

A note from Gnorman
What an experienced grower watches for around here
In and around Malta, two things run higher than the national average — Nitrate (36 sites) and Mining (3 sites). That's not a problem with your land — it's information about it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Check your specific parcel in Malta
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
Malta Average
- ●USDA Zones 5a-6b
- ●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 Malta
Pull a site-specific report for your exact address in Malta, Idaho — 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 Malta, Idaho
- USDA Hardiness Zones: 5a-6b (USDA PHZM 2023)
- Last Hard Freeze (28°F): Apr 23 (town normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
- First Hard Freeze (28°F): Oct 17 (town normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
- Days Between Hard Freezes: ~177 (town normal, NOAA 1991–2020 Climate Normals)
- Land Area: 883 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 Malta, Idaho?
Malta sits in USDA hardiness zones 5a-6b, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.
Is it too late to plant in Malta?
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 26; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 23 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 17 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.
When does frost risk typically end in Malta?
The last hard freeze (28°F) in Malta typically lands around Apr 23, per NOAA 1991–2020 climate normals — an earlier marker than the light-frost dates many planting charts quote. That marks the hard freeze, not the last light frost — light frosts can still bite for a few more weeks, so tender transplants usually wait another 2–3 weeks.
When is the first frost in Malta?
The first hard freeze (28°F) in Malta typically arrives around Oct 17, 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 Malta?
Malta's zones 5a-6b support a wide range — strong performers include Potato, Apple, Hop, Cherry, and Lentil. 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 Malta, really?
Officially, Malta sits in USDA zones 5a-6b (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 Malta?
The federal record around Malta is a meaningful one — 50 documented sites — 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 Malta?
As the season closes around the first 28°F hard freeze near Oct 17 (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 Malta 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.
