Colorado growing guide: zones, planting dates and where to start
How Colorado zones change planting dates, with spring dates for its main growing region.
Not yet expert-reviewed. Written by BAU Farm Intelligence from public extension and agency sources. Check dates and program details with your local extension office.
Zones across Colorado
Colorado covers USDA Zones 6a–6b on our calendar. A date that works in one part of the state can be weeks off in another, so plant by your zone, not the state.
- Zone 6a — Pueblo and the lower Arkansas valley. Average last frost 05/01, first frost 10/01 (about 153 frost-free days).
- Zone 6b — Grand Junction and the western slope. Average last frost 04/24, first frost 10/08 (about 167 frost-free days).
Spring dates for Pueblo and nearby covered areas (Zone 6a)
- Tomatoes: set out May 8 – May 29; fall June 18 – July 9
- Peppers: set out May 15 – June 5; fall July 2 – July 23
- Sweet corn: seed May 1 – May 22; fall July 2 – July 23
- Cucumbers: set out May 8 – May 29; fall July 16 – August 6
- Summer squash: seed May 8 – May 29; fall July 23 – August 13
- Green beans (bush): seed May 1 – May 22; fall July 16 – August 6
- Cabbage: set out April 3 – April 24; fall June 18 – July 9
- Broccoli: set out April 3 – April 24; fall June 18 – July 9
These are averages worked out from frost dates, not a state extension schedule. Adjust for your field and the season.
Published costs per acre
- 2024 Western Colorado Onions (Furrow Irrigated) — Estimated Production Costs & Returns (Colorado State University Extension — Agriculture & Business Management, 2024): about $8,791 per acre.
Where to sell in Colorado
- State buy-local program: the Colorado Department of Agriculture runs Colorado Proud. Members can be listed for grocery, restaurant and school buyers looking for in-state product — ask about joining and any marketing directories.
- Established market: Boulder County Farmers Markets (Boulder and Longmont). Visit on a market morning and talk to the produce dealers before you plant, not after harvest.
- Farmers markets, CSAs and on-farm stands: the USDA Local Food Directories list them by state, so you can see who already sells near you and which markets still need your crop.
- Schools and institutions: ask your state's farm-to-school contact (usually through the agriculture or education department) what they buy and when.
- Buyers on BAU: buyers post what they need on the marketplace, and you can list your crop window there for free.
Call before you count on any buyer: programs and market hours change, and a price talked through in winter is worth more than one found at harvest.
Farm taxes in Colorado
- Income tax: Flat state income tax.
- Sales tax on inputs: Farm equipment, seed, fertilizer and other items used in production are exempt; local rules can differ, so ask the vendor.
- Farmland property tax: Land used as a farm is classified agricultural and valued on its earning capacity, not market value.
Rates and forms change. Confirm with the state revenue department or a farm tax preparer before you file — this is a plain-language guide, not tax advice. Our farm tax estimator covers the federal deductions every state shares.
Grants and cost-share in Colorado
- Specialty Crop Block Grant (Department of Agriculture)
- Colorado Department of Agriculture soil health and conservation grants
- USDA NRCS EQIP cost-share and FSA microloans through your county USDA service center
- Western SARE farmer and rancher grants for on-farm trials
See the grant tracker for deadlines we follow.
Who to call
- Colorado State University Extension — county offices for soil tests, varieties and pest help
- Your county USDA service center (FSA and NRCS) for loans, cost-share and farm numbers