Can I Grow Olive in Idaho?

Olive in Idaho — the short answer

Idaho is not one climate

Where Olive Stands in Idaho

Zone Comparison

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS, and university Extension sources — per-field provenance varies and is published with the dataset. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.

When to Plant Olive in Idaho

Timing tuned to sub-state frost dates — Valley County, not the statewide average.

Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: Growable Ground Plant Database — frost-free days from FAO ECOCROP, days to harvest from university Extension production guides, and growing-degree-day and chill-hour minimums that are compilation estimates rather than published figures. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.

Growing Season Fit

The zone check says olive survives winter in part of Idaho, not across all of it. Whether the season is long enough — and warm enough — is a different question.

GDD and chill-hour figures are computed from PRISM 1991-2020 monthly climate normals; frost-free days from NOAA Regional Climate Centers ACIS, 1991-2020. Each is the state median across its counties (P25/P75 span the within-state spread). Hardiness-zone range is USDA PHZM 2023.

Soil + Drainage Fit

Olive tolerates a wide pH range (pH 5.3-8.5) — 3.2 units, acid ground through alkaline — so soil acidity is rarely what limits it in Idaho. A soil test is still worth having, but for what else it tells you about this site, not to clear this plant. It will grow across that whole span, but it does best between pH 6 and 7 — worth knowing before you decide whether a Idaho soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Idaho site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.

Plant pH requirements: FAO ECOCROP and USDA PLANTS, with the remaining rows from other published sources or Growable Ground compilation. Drainage: FAO ECOCROP, with the remaining rows from other published sources or Growable Ground compilation. Idaho soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

Before you plant olive for food

Anything you grow to eat takes up what is in the ground it grows in, so what is on record near you is worth knowing before olive goes in. What follows is Idaho’s documented federal record at state scale — a screening signal, not a soil test, and not a statement about any one lot.

Safe to Grow Here?

What the federal record shows across Idaho — and how to grow with it.

Federal record: High

We checked the federal record across Idaho — 21,100 documented sites across 8 of the 9 source types we track.

The most significant on record: 215 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.

Idaho carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.

See every recorded site across Idaho on the mapKnow before you grow — the guide

Explore the live map

Nitrate9,840Underground Storage Tanks5,274Mining3,980Brownfields1,189Toxics Release Inventory325

Sources Checked

across Idaho

Nitrate Monitoring

9,840

Underground Storage Tanks

5,274

Mining Sites

3,980

Brownfields

1,189

Toxics Release Inventory

325

Concentrated Animal Feeding

218

Superfund

215

PFAS Sampling

59

Severity Distribution

across Idaho

High1,461Moderate14,067Low5,572

Highest-Severity Sites

A. D. & M. Mine

Mining Sites · Past Producer

Ada Jane and Bismuth Claims

Mining Sites · Unknown

Ader Group

Mining Sites · Past Producer

Ajax

Mining Sites · Past Producer

Ajax Mine

Mining Sites · Past Producer

A note from Gnorman

What an experienced grower watches for around here

In and around Idaho, two things run higher than the national average across Idaho — Mining (3,980 sites) and Nitrate (9,840 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.

Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.

Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.

Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.

Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).

build up with a clean-soil raised bedread your soil before you plantbuild soil that holds onto nitrogenSee what's flagged near Idaho

Explore the contamination map around Idaho

Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.

What Else to Consider for Olive in Idaho

Zone compatibility tells you about winter cold survival — but Idaho growers also need to think about:

What to actually do about these — and the constraints that apply to every Idaho grower, not just olive — is covered on the Idaho growing guide.

Timing shifts within Idaho

Idaho isn't one climate. In Valley County, the last hard freeze (28°F) holds until about Jun 14 — roughly 42 days later than the recorded state median — so plant olive to your county's window, not the statewide date.

Olive needs about 365 days of frost-free season to complete its cycle. No Idaho county gives it that outdoors: even Nez Perce County, the state’s longest season at 216 frost-free days, falls 149 days short — so it needs transplants, a short-season variety, or covered growing.

Across Idaho’s 44 counties the frost-free season runs from 94 days in Valley County to 216 days in Nez Perce County — a spread of 122 days, which is why a single statewide planting date misleads. The median Idaho county sees 160 frost-free days, which is 205 days short of what olive needs — so on a typical Idaho parcel this is a transplant-or-protect crop, not a direct-sow one.

County last-freeze dates and frost-free day counts: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). Olive's 365-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.

Idaho Cooperative Extension

For Idaho-specific cultivar recommendations, planting calendars, and pest pressure for olive, the canonical source is University of Idaho Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Olive native to Idaho?

No — the USDA PLANTS Database lists Olive as introduced rather than native in the Lower 48, so it is not part of Idaho's native flora. It grows here as a garden plant; pairing it with a few Idaho natives keeps local pollinators fed too.

Looking for plants that belong here? The Idaho growing guide lists USDA-documented natives for the state.

Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.

Common Questions About Growing Olive in Idaho