What to plant in October in Idaho
In Idaho (ID), the average first fall frost (September 25) has passed by mid-October. The state averages 138 frost-free days a year (last frost May 10, first frost September 25; USDA zones 3b, 4b, 5b, 6a, 6b, 7a).
2 crops have a sowing or planting window this month: shallot, garlic - and 1 of those windows close during October.
Dates here come from Idaho frost dates (last frost May 10, first frost Sep 25). For one crop in detail, see when to plant garlic, tomato or lettuce in Idaho.
Idaho covers a very wide range of climates, so dates near you can be two weeks or more either side of these. Enter your ZIP code in the planting calendar for dates tuned to your town.
Idaho: planting activity through the year
Last chance in October
Shallot (plant in fall (after first frost), by Oct 16)
For fall and winter harvests (2)
Sowings counted back from Idaho's first fall frost, so the crop matures before the cold - or, for garlic and similar, planted after it.
Harvesting in October
First harvests expected this month from crops sown or planted on time earlier in the season.
Planting dates for popular crops in Idaho
Every crop has its own full-year dates for Idaho: indoor start, transplant or direct sowing, and harvest.
Spring bulbs to plant in October in Idaho
Tulips, daffodils, hyacinths and crocus are planted in fall, once the soil has cooled and before it freezes. The exact window depends on the state, so our bulb guide quotes what each extension service says.
After the first frost: October garden jobs in Idaho
- The average first frost (September 25) has passed - pull frost-killed tender plants and compost the healthy ones; bin or burn anything that had blight or mildew.
- Plant garlic now (Oct 6 – Oct 23): single cloves, pointy end up, 2 inches deep and 6 inches apart, then mulch.
- Leave cold-hardy roots (carrots, parsnips, leeks) in the ground under a thick mulch and dig them as needed.
- Clean and oil tools, drain hoses, and note what worked this year while you still remember - it makes next year's plan far easier.
USDA zone chart for Idaho
Idaho spans USDA zones 3b, 4b, 5b, 6a, 6b, 7a. Colder zones, usually higher or further inland, have a later last spring frost and an earlier first fall frost than the state average.
Questions gardeners ask
What vegetables can I plant in Idaho in October?
2 crops have a window in October: shallot, garlic. The tables above give the exact dates for each.
Is it too late to plant garlic in Idaho in October?
No - plant in fall (after first frost) runs Oct 6 – Oct 23 in Idaho, so do it before October 23.
Is it too late to plant tomatoes in Idaho in October?
For this year, yes - the tomato windows in Idaho have closed. The next step is to start seeds indoors from about March 15.
When is the first frost in Idaho?
The statewide average first fall frost is around September 25 and the last spring frost around May 10. Idaho covers a wide range of climates, so local dates can differ by two weeks or more - look yours up by ZIP code.
What can I harvest in Idaho in October?
From plantings made on time: cauliflower, cabbage, lettuce, luffa (loofah gourd), brussels sprouts, peanut, napa cabbage, fennel (bulb), cilantro / coriander, carrot.
What to plant in October in other states
Dates are computed from Idaho’s statewide average frost dates (from NOAA/NCEI climate normals) and each crop’s timing in our crop database. Your garden may be a week or two either side - for dates tuned to your ZIP code, use the planting calendar.