What to plant in October in Colorado
In Colorado (CO), the average first fall frost (October 1) has passed by mid-October. The state averages 149 frost-free days a year (last frost May 5, first frost October 1; USDA zones 3b, 4b, 5a, 5b, 6a, 7a).
2 crops have a sowing or planting window this month: shallot, garlic.
Dates here come from Colorado frost dates (last frost May 5, first frost Oct 1). For one crop in detail, see when to plant garlic, tomato or lettuce in Colorado.
Colorado 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.
Colorado: planting activity through the year
For fall and winter harvests (2)
Sowings counted back from Colorado'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 Colorado
Every crop has its own full-year dates for Colorado: indoor start, transplant or direct sowing, and harvest.
Spring bulbs to plant in October in Colorado
Late September is preferred and September and October are the best months. Bulbs planted after October may not root well enough to flower evenly in spring. (Colorado State University Extension) ↗
After the first frost: October garden jobs in Colorado
- The average first frost (October 1) 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 12 – Oct 29): 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 Colorado
Colorado spans USDA zones 3b, 4b, 5a, 5b, 6a, 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 Colorado 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 Colorado in October?
No - plant in fall (after first frost) runs Oct 12 – Oct 29 in Colorado, so do it before October 29.
Is it too late to plant tomatoes in Colorado in October?
For this year, yes - the tomato windows in Colorado have closed. The next step is to start seeds indoors from about March 10.
When is the first frost in Colorado?
The statewide average first fall frost is around October 1 and the last spring frost around May 5. Colorado 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 Colorado in October?
From plantings made on time: luffa (loofah gourd), peanut, broccoli, cauliflower, cabbage, lettuce, brussels sprouts, bok choy / pak choi, napa cabbage, mustard greens.
When should I plant spring bulbs in Colorado?
Late September is preferred and September and October are the best months. Bulbs planted after October may not root well enough to flower evenly in spring. (Colorado State University Extension). See the bulb planting guide for depth and spacing.
What to plant in October in other states
Dates are computed from Colorado’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.