When to plant · 9 cities · zones 5b–7a
When to plant basil in Idaho
Start Genovese Basil seeds indoors around Apr 16 and transplant around May 28 — the Idaho statewide median, counted from a last spring frost of May 14 across 253 ZIP codes and 112 NOAA stations.
The rule: Basil is damaged below about 50 °F, well before frost: transplant two weeks after the last frost, not on it.
Idaho basil, by step
Statewide median last frost May 14, first fall frost Sep 29, 2027 season. Each cultivar's own indoor lead time and days to maturity, same engine as the Plan Builder.
| Cultivar | Start indoors | Plant out | First harvest | Days |
|---|---|---|---|---|
| Genovese BasilGenovese | Apr 16 | May 28 | Jul 27 | 60 from transplant |
Tight means first harvest lands within two weeks of the median first fall frost. Statewide dates are the ZIP-weighted median of every NOAA 1991–2020 station Idaho's ZIP codes resolve to; 30 of 283 ZIPs have no datable freeze and are left out.
Basil in Idaho, city by city
Genovese Basil, scheduled from each city's nearest NOAA station — the same dates as its frost page.
| City | Last frost | Start indoors | Plant out | First harvest |
|---|---|---|---|---|
| Boisezone 7a | Apr 24 | Mar 27 | May 8 | Jul 7 |
| Meridianzone 7a | Apr 24 | Mar 27 | May 8 | Jul 7 |
| Nampazone 7a | Apr 29 | Apr 1 | May 13 | Jul 12 |
| Caldwellzone 7a | Apr 29 | Apr 1 | May 13 | Jul 12 |
| Idaho Fallszone 5b | May 9 | Apr 11 | May 23 | Jul 22 |
| Pocatellozone 6a | May 2 | Apr 4 | May 16 | Jul 15 |
| Coeur d'Alenezone 6b | Apr 22 | Mar 25 | May 6 | Jul 5 |
| Twin Fallszone 7a | Apr 25 | Mar 28 | May 9 | Jul 8 |
| Post Fallszone 6b | Apr 22 | Mar 25 | May 6 | Jul 5 |
What these basil become
What Idaho basil need
Genovese Sweet Basil Seed
The large-leaf, low-anise Italian basil that pesto is defined by. Thai and lemon basils are good plants and wrong ingredients.
Organic Seed Starter Potting MixMust have
Seed-starting mix is not potting soil with a nicer label — it is finer, lighter, and low in nutrients on purpose, because a seedling's first roots want air and moisture, not fertiliser.
T8 Full-Spectrum Grow Lights, 1 ft 4-packMust have
A south window in March delivers a fraction of the light a pepper seedling needs, and the plant tells you by stretching. Two inches of LED above the canopy for 16 hours a day fixes it permanently.
5-Gallon Fabric Grow Bags, 5-Pack
Fabric pots air-prune roots and drain faster than a plastic pot can, which is the entire reason container tomatoes fail. Five gallons is the honest minimum for a pepper; a tomato wants ten.
Ocean Forest Potting SoilMust have
Pre-charged with enough nutrition to carry a transplant for its first month without feeding, which is exactly the window when most container plants stall.
6" Micro-Tip Pruning SnipsMust have
Ninety percent of sauce-garden cutting is snipping a pepper stem or a basil node, and a fine-tipped snip does it better than any pruner. Pulling peppers by hand tears the branch.
Mesh Strainers, Stainless, 3-Count
The last pass before bottling. A fine mesh catches the skin fragments and seed shards that make a hot sauce gritty and clog a woozy bottle's dripper insert.
Paid links. We earn a commission from Amazon if you buy; you pay the same. Disclosure.
Basil in Idaho: questions
When should I plant basil in Idaho?
Transplant around May 28 at the statewide median; across the state that date runs from May 8 in the warmest tenth of Idaho's ZIP codes to Jun 23 in the coldest. To cut the freeze risk to one year in ten, count from Jun 3 instead of the median last frost. Use the city table for your own town.
When do I start basil seeds indoors in Idaho?
Around Apr 16 for Genovese Basil: 4 weeks before the statewide median last frost, on soil held at 70–80 °F.
When is the last frost in Idaho?
The ZIP-weighted median of NOAA 1991–2020 station medians is May 14. In the warmest tenth of Idaho's ZIP codes the median last frost falls on or before Apr 24; in the coldest tenth, on or after Jun 9.
When will Idaho basil be ready to harvest?
Genovese Basil planted on the statewide date is ready around Jul 27: 60 days from transplant.
More for Idaho
- When to plant tomatoes
- When to plant peppers
- When to plant tomatillos
- When to plant onions
- When to plant cilantro
- When to plant carrots
- When to plant mustard greens
Basil in every state → · Idaho frost dates → · How frost-date math works →