Rio Blanco County, CO — Planting Guide
Rio Blanco County is in USDA Zone 5a. The average last spring frost is June 2 and the first fall frost is September 17, giving you a growing season of approximately 107 days.
At an elevation of 6,974 ft, Rio Blanco County receives approximately 19 in of rainfall annually. Summer highs average 86°F with winter lows around 16°F. The predominant soil type is Loam.
Based on 31 years of NOAA climate station data, the last frost date here varies by 47 days year to year — ranging from May 3 in warm years to June 20 in cold years. The growing season is trending shorter by about 2.69 days per decade. Rio Blanco County scores 28/100 (Challenging) on the Microclimate Index.
🌡️ Zone
5a (-20°F to -15°F min)
❄️ Last Frost
June 2
🍂 First Frost
September 17
📅 Growing Season
107 days
⛰️ Elevation
6,974 ft
🌧️ Annual Rainfall
19 in
Monthly Watering Calendar
When you'll need to water your garden — based on average monthly rainfall vs. the ~1 inch/week most gardens need.
View detailed monthly data
| Month | Avg Rainfall | Rainy Days | Extra Water Needed | Watering Effort |
|---|---|---|---|---|
| Jan | 1.3 in | 6 days | — | None |
| Feb | 1.3 in | 6 days | — | None |
| Mar | 1.8 in | 9 days | — | None |
| Apr | 2 in | 7 days | 2.3 in | High |
| May | 2.1 in | 7 days | 2.2 in | High |
| Jun | 1.3 in | 4 days | 3 in | High |
| Jul | 1.4 in | 6 days | 2.9 in | High |
| Aug | 1.9 in | 6 days | 2.4 in | High |
| Sep | 1.6 in | 6 days | 2.7 in | High |
| Oct | 1.6 in | 6 days | 2.7 in | High |
| Nov | 1.5 in | 5 days | — | None |
| Dec | 1.3 in | 6 days | — | None |
Annual total: 19.1 in. Gardens typically need ~1 inch of water per week during the growing season. Months marked "None" for extra water are outside the active growing season for your zone — most gardens are dormant and don't need irrigation during those months.
Rio Blanco County Soil Profile
Soil Type
Loam
Soil pH
6.4-7.7
Drainage
Well Drained
Frost Risk Probability
Based on 31 years of NOAA weather station data from 3 stations
Beginners: Plant frost-sensitive crops (tomatoes, peppers, squash) after the "Safe" date on the left. Harvest or cover them before the "Protect by" date on the right. Hardy crops (lettuce, peas, kale) can go in the yellow transition zones.
How to read this table: "Conservative" means you're safe from frost 9 out of 10 years — best for beginners and frost-sensitive crops. "Average year" is the typical date. "Aggressive" means only 1 in 10 years is that warm — experienced gardeners with frost protection can try these dates.
| Planting Strategy | Last Spring Frost | First Fall Frost | Frost-Free Days |
|---|---|---|---|
| Conservative (safest) | Jun 20 | Oct 10 | 112 days |
| Cautious | Jun 11 | Sep 25 | 106 days |
| Average year | Jun 2 | Sep 17 | 107 days |
| Optimistic | May 19 | Sep 8 | 112 days |
| Aggressive (risky) | May 3 | Aug 30 | 119 days |
Not very — frost dates can vary by ±47 days year-to-year. Use the "Conservative" row in the table below, and keep row covers handy for surprise late frosts.
Yes — growing seasons are getting shorter here (about 2.7 days per decade). Use the "Conservative" dates and choose fast-maturing varieties.
Gardening Difficulty Score
Rio Blanco County has challenging growing conditions. Season extension and careful variety selection are essential.
Local Gardening Help in Rio Blanco County
Free expert help is closer than you think. Your county's cooperative extension office connects you with trained gardeners, soil testing labs, and local programs — all specific to Rio Blanco County's climate and soil.
County Extension Office
Rio Blanco County Colorado State University Extension Extension Office
Phone: 970-491-6281
Visit Extension Office Website →
Extension offices are run by land-grant universities and funded by the USDA. Their advice is free, research-based, and tailored to your county's specific conditions.
Master Gardener Program
Free gardening help from trained volunteers
Master Gardeners are community volunteers who complete 40–60 hours of university horticultural training. They answer gardening questions, diagnose plant problems, and offer workshops — all free.
Many extension offices run a Master Gardener hotline where you can call or email with photos of plant problems for free diagnosis.
Soil Testing
Available through your extension office
Before amending your soil, get it tested. Your extension office offers soil testing (typically $10–$25) that tells you exact pH, nutrient levels, and amendment recommendations specific to what you want to grow.
Services Available in Rio Blanco County
Finding local nurseries & garden centers in Rio Blanco County
Why Buy Local
Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Rio Blanco County's soil and climate that big-box stores can't. Plants from local growers are typically hardier because they're already acclimated to your zone.
How to Find Them
Search for "nurseries near Rio Blanco County CO" or "garden center Rio Blanco County" on Google Maps. Also check with your extension office — they often maintain lists of reputable local nurseries and plant sales.
Community gardens & gardening groups
Community gardens are a great way to learn from experienced gardeners in your area, especially if you're limited on space. Search "community garden Rio Blanco County CO" or check your extension office and local parks department. Facebook groups like "Rio Blanco County Gardeners" or "Colorado Gardening" are also excellent for local advice and plant swaps.
What to Plant After Your Harvest
After your first crops finish, use the remaining frost-free days to grow a second round.
Sunlight & Day Length
Monthly daylight hours and peak sun — critical for onion varieties, photoperiod-sensitive plants, and solar garden planning.
Longest Day
14.8 hours
Summer solstice daylight
Shortest Day
9.2 hours
Winter solstice daylight
Peak Sun Hours
11.1 hr/day peak (summer)
Peak sun hours (green dashed line below) account for cloud cover — this is the usable direct sunlight your garden actually receives. Most vegetables need 6+ peak sun hours.
Onion tip: Your long summer days (14+ hours) support long-day onion varieties like Walla Walla, Sweet Spanish, and Ailsa Craig.
View detailed monthly data
| Month | Daylight Hours | Peak Sun Hours | Day Length |
|---|---|---|---|
| January | 9.5 hr | 5.1 hr | Short day |
| February | 10.5 hr | 5.9 hr | Short day |
| March | 11.7 hr | 7.3 hr | Short day |
| April | 13.1 hr | 7.6 hr | Neutral |
| May | 14.2 hr | 9 hr | Long day |
| June | 14.8 hr | 11.1 hr | Long day |
| July | 14.6 hr | 10.1 hr | Long day |
| August | 13.6 hr | 9 hr | Neutral |
| September | 12.2 hr | 8.3 hr | Neutral |
| October | 10.9 hr | 7 hr | Short day |
| November | 9.7 hr | 5.6 hr | Short day |
| December | 9.2 hr | 4.9 hr | Short day |
Peak sun hours factor in typical cloud cover — use these for solar panel and shade-planning calculations.
Soil Temperature & Composting Calendar
Monthly soil temps tell you when to plant warm-season crops, and when your compost pile is actively working.
Plant Warm Crops When
Soil reaches 60°F+
Soil rarely reaches 60°F — use black plastic mulch to warm soil.
Best Month to Compost
Jul
Microbial activity peaks when soil is warm.
Active Composting
2 months
Short season — insulate pile or use indoor vermicomposting.
View detailed monthly data
| Month | Soil 4" Deep | Soil 8" Deep | Compost Activity | Time to Finish |
|---|---|---|---|---|
| Jan | 2°F | 10°F | ❄️ Dormant | ~36 weeks |
| Feb | 5°F | 9°F | ❄️ Dormant | ~36 weeks |
| Mar | 12°F | 16°F | ❄️ Dormant | ~36 weeks |
| Apr | 24°F | 23°F | ❄️ Dormant | ~36 weeks |
| May | 37°F | 34°F | ❄️ Dormant | ~36 weeks |
| Jun | 48°F | 42°F | 🐢 Slow | ~24 weeks |
| Jul | 54°F | 51°F | ♻️ Active | ~14 weeks |
| Aug | 56°F | 52°F | ♻️ Active | ~14 weeks |
| Sep | 50°F | 49°F | 🐢 Slow | ~24 weeks |
| Oct | 36°F | 40°F | ❄️ Dormant | ~36 weeks |
| Nov | 24°F | 28°F | ❄️ Dormant | ~36 weeks |
| Dec | 11°F | 16°F | ❄️ Dormant | ~36 weeks |
Highlighted rows = soil 60°F+ (safe for warm-season transplants). Compost finishes fastest during peak activity months.
Pest & Disease Pressure in Rio Blanco County
Computed from local climate patterns — warmer, humid conditions increase pest generations and fungal disease risk.
Insect Pest Pressure
Moderate — common pests appear but manageable with monitoring.
Disease Risk
Low disease risk — dry conditions reduce fungal problems.
Seasonal Risk
View 5 common pests in your area
| Pest | Risk Level | Peak Months |
|---|---|---|
| Aphids | Moderate | May, Jun, Jul, Aug |
| Japanese beetles | Moderate | Jun, Jul, Aug |
| Squash bugs | Moderate | Jun, Jul, Aug |
| Tomato hornworms | Moderate | Jul, Aug |
| Cabbage loopers | Low | May, Jun, Jul, Aug |
Organic pest management tips
- Maintain healthy soil with regular compost additions to build natural pest resistance
- Practice crop rotation annually to break pest cycles
- Encourage beneficial insects with flowering herbs like dill, fennel, and yarrow
Cover Crops for Rio Blanco County
Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with county-specific planting dates.
Fall Cover Crops (6 options) — Plant after harvest to protect soil over winter
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Austrian winter peas | Jul 24 | May 19 | ✓ Yes | Fixes nitrogen, good for heavy clay soils |
| Daikon radish | Jul 27 | May 19 | — | Deep taproot breaks compaction, excellent for clay soils |
| Hairy vetch | Jun 22 | May 12 | ✓ Yes | Excellent nitrogen fixer, good for depleted soils |
| Oats | Aug 6 | May 19 | — | Quick biomass, winterkills in cold zones — no spring tillage needed |
| Winter rye | Jun 10 | May 19 | — | Suppresses weeds, prevents erosion, breaks up compacted soil |
| Winter wheat | Jun 20 | May 12 | — | Erosion control, weed suppression, good biomass |
Spring Cover Crops (3 options) — Build soil before the main growing season
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Buckwheat | Jun 4 | Jul 16 | — | Rapid growth, attracts pollinators, suppresses weeds |
| Sorghum-sudan grass | Jun 9 | Jul 23 | — | Massive biomass, breaks compaction, suppresses nematodes |
| White clover | May 7 | Jul 23 | ✓ Yes | Living mulch, fixes nitrogen, permanent ground cover |
Summer Cover Crops (1 options) — Fill gaps and suppress weeds between plantings
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Sunflowers | Jun 30 | Sep 3 | — | Deep roots break compaction, attract pollinators and beneficial insects |
Wind & Microclimate
Wind dries soil, stresses plants, and affects frost patterns. Understanding your exposure helps with garden placement.
Seasonal Wind Speed
Spring: 15 mph Summer: 10 mph
Fall: 13 mph Winter: 15 mph
Prevailing wind: W. Windy area — plant a windbreak hedge on the W side of your garden.
Windbreak Benefit
7.2/10
Strongly recommended — a windbreak (fence, hedge, or row of tall crops like corn or sunflowers) will significantly improve garden yields.
Frost Pocket Risk
High
Hilly terrain with 2,871 ft of elevation range — cold air pools in low spots. Avoid planting frost-sensitive crops in valleys.
Rainwater Harvesting Potential
How much water you can collect, when to collect it, and what size system you need for your garden.
Annual Collection
9,519 gal
Per 1,000 sq ft of roof area (at 80% collection efficiency)
Recommended Setup
8 rain barrels (55 gal each)
For a typical 500 sq ft garden. Serious collectors: consider a 1,750 gal tank.
Legal Status
Limited
Your state has quantity limits on rainwater collection — check local regulations before installing large systems.
Best Collection Months
Mar, Apr, May, Aug
Highest rainfall months — your barrels will fill up quickly during these months.
Months to Draw From Storage
Feb, Jun, Dec
Dry months when you'll rely on stored water — size your storage for this gap.
Rainwater collection tips for your area
- Your county receives approximately 19.1 inches of rain per year
- A 1,000 sq ft roof can collect roughly 9,519 gallons annually
- Check CO state regulations — rainwater harvesting has quantity limits
- In your dry climate, every drop counts — consider a larger cistern system
- Position collection tanks in shade to reduce evaporation and algae growth
Soil & Growing Conditions in Rio Blanco County
Soil Type
Loam
Soil pH 6.4–7.7 · Well Drained drainage
Good candidate for raised beds to maximise drainage and extend the season.
Watering Needs
Drought stress: 7.5/10
High drought stress. Consistent irrigation is essential — consider drip systems, heavy mulch, and drought-tolerant varieties.
Season Tips
107-day frost-free season
A short season means indoor starts are critical for warm-season crops. Prioritise cold-hardy, fast-maturing varieties and use row covers to extend autumn harvests.
Free Garden Planner
Plan your entire garden season — organize planting dates, track what you're growing, and know exactly when to start seeds, transplant, and harvest.
Recommended for Your Garden
Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.
Get instant, accurate soil pH readings to fine-tune your amendments.
Boost soil fertility and structure with rich, well-aged organic compost.
🥬 Vegetables to Grow in Rio Blanco County
106 vegetables that grow well in Zone 5a with planting dates for Rio Blanco County.
Show all 106 vegetables with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Acorn Squash | Apr 28 | Jun 9 | Jun 16 | Sep 8 – Oct 13 | 80–100 |
| Amaranth | Apr 7 | Jun 9 | Jun 16 | Sep 15 – Nov 3 | 90–120 |
| Arugula | Apr 28 | May 19 | Jun 2 | Jul 7 – Sep 8 | 30–50 |
| Asparagus | — | — | Jun 16 | — | 730–1095 |
| Beets | — | May 19 | — | Jul 14 – Aug 11 | 50–70 |
| Belgian Endive | Apr 28 | May 19 | Jun 2 | Sep 22 – Nov 17 | 110–150 |
| Bitter Melon | Apr 7 | Jun 9 | Jun 16 | Aug 18 – Sep 29 | 60–90 |
| Black Beans | — | Jun 9 | — | Sep 8 – Oct 27 | 90–120 |
| Bok Choy | Apr 28 | May 19 | Jun 2 | Jul 14 – Aug 18 | 40–60 |
| Broccoli | Apr 28 | May 19 | Jun 2 | Aug 4 – Sep 15 | 60–90 |
| Broccoli Rabe | Apr 28 | May 19 | Jun 2 | Jul 14 – Aug 18 | 40–60 |
| Brussels Sprouts | Apr 28 | May 19 | Jun 2 | Sep 1 – Oct 27 | 90–130 |
| Butternut Squash | Apr 28 | Jun 9 | Jun 16 | Sep 15 – Oct 20 | 85–110 |
| Cabbage | Apr 28 | May 19 | Jun 2 | Aug 4 – Sep 29 | 60–100 |
| Calabash | Apr 7 | Jun 9 | Jun 16 | Sep 8 – Nov 3 | 80–120 |
| Carrots | — | May 19 | — | Jul 21 – Aug 25 | 60–80 |
| Cauliflower | Apr 28 | May 19 | Jun 2 | Jul 28 – Sep 29 | 55–100 |
| Celeriac | Apr 28 | May 19 | Jun 2 | Sep 15 – Oct 20 | 100–120 |
| Celery | Apr 28 | May 19 | Jun 2 | Aug 25 – Oct 20 | 80–120 |
| Celtuce | Apr 28 | May 19 | Jun 2 | Aug 4 – Sep 15 | 60–90 |
| Chard | Apr 28 | May 19 | Jun 2 | Jul 28 – Sep 15 | 50–60 |
| Chickpeas | Apr 28 | May 19 | Jun 2 | Aug 25 – Oct 6 | 80–110 |
| Chicory | Apr 28 | May 19 | Jun 2 | Aug 4 – Sep 15 | 60–85 |
| Chinese Cabbage | Apr 28 | May 19 | Jun 2 | Jul 28 – Aug 25 | 50–70 |
| Christmas Lima Beans | Apr 7 | Jun 9 | Jun 16 | Sep 8 – Oct 13 | 80–100 |
| Collard Greens | Apr 28 | May 19 | Jun 2 | Jul 28 – Sep 29 | 55–75 |
| Corn | — | Jun 9 | — | Aug 11 – Oct 6 | 60–100 |
| Cowpeas | — | Jun 9 | — | Aug 11 – Sep 22 | 60–90 |
| Cress | Apr 28 | May 19 | Jun 2 | Jun 16 – Jul 7 | 14–21 |
| Crookneck Squash | Apr 28 | Jun 9 | Jun 16 | Aug 4 – Sep 1 | 45–60 |
| Crosne | — | May 19 | — | Oct 20 – Nov 3 | 150–200 |
| Cucumber | Apr 28 | Jun 9 | Jun 16 | Aug 11 – Oct 6 | 50–70 |
| Daikon | — | May 19 | — | Jul 14 – Aug 11 | 50–70 |
| Delicata Squash | Apr 28 | Jun 9 | Jun 16 | Sep 8 – Oct 13 | 80–100 |
| Edamame | — | Jun 9 | — | Aug 25 – Oct 6 | 75–100 |
| Eggplant | Mar 24 | Jun 9 | Jun 16 | Aug 25 – Oct 27 | 65–85 |
| Endive | Apr 28 | May 19 | Jun 2 | Jul 21 – Aug 25 | 45–65 |
| Escarole | Apr 28 | May 19 | Jun 2 | Jul 28 – Aug 25 | 50–70 |
| Fava Beans | Apr 28 | May 19 | Jun 2 | Aug 18 – Sep 29 | 75–100 |
| Fennel | Apr 7 | Jun 9 | Jun 16 | Aug 18 – Sep 29 | 60–90 |
| Garlic | — | — | — | — | 90–240 |
| Green Beans | — | Jun 9 | — | Aug 4 – Sep 29 | 50–65 |
| Horseradish | — | — | Jun 16 | Oct 20 – Dec 1 | 120–180 |
| Hot Peppers | Mar 24 | Jun 9 | Jun 16 | Aug 25 – Dec 1 | 70–120 |
| Hubbard Squash | Apr 28 | Jun 9 | Jun 16 | Sep 29 – Nov 3 | 100–120 |
| Kabocha | Apr 28 | Jun 9 | Jun 16 | Sep 15 – Oct 13 | 85–100 |
| Kai Lan | Apr 28 | May 19 | Jun 2 | Jul 21 – Aug 18 | 45–60 |
| Kale | Apr 28 | May 19 | Jun 2 | Jul 28 – Sep 22 | 50–70 |
| Kidney Beans | — | Jun 9 | — | Sep 8 – Oct 13 | 85–110 |
| Kohlrabi | Apr 28 | May 19 | Jun 2 | Jul 21 – Aug 25 | 45–65 |
| Komatsuna | Apr 28 | May 19 | Jun 2 | Jul 7 – Aug 11 | 35–50 |
| Leeks | Apr 28 | May 19 | Jun 2 | Sep 1 – Nov 17 | 90–150 |
| Lentils | Apr 28 | May 19 | Jun 2 | Aug 25 – Oct 6 | 80–110 |
| Lettuce | Apr 28 | May 19 | Jun 2 | Jul 7 – Sep 15 | 30–60 |
| Lima Beans | — | Jun 9 | — | Aug 11 – Sep 22 | 60–90 |
| Mache | Apr 28 | May 19 | Jun 2 | Jul 14 – Aug 18 | 40–60 |
| Melon | Apr 28 | Jun 9 | Jun 16 | Aug 25 – Oct 13 | 70–100 |
| Microgreens | Apr 28 | May 19 | Jun 2 | Jun 9 – Jul 7 | 7–21 |
| Mitsuba | Apr 28 | May 19 | May 26 | Jul 21 – Sep 15 | 50–70 |
| Mizuna | Apr 28 | May 19 | Jun 2 | Jul 7 – Aug 4 | 30–45 |
| Mustard Greens | Apr 28 | May 19 | Jun 2 | Jul 7 – Sep 8 | 30–50 |
| Napa Cabbage | Apr 28 | May 19 | Jun 2 | Jul 28 – Sep 1 | 55–75 |
| New Zealand Spinach | Apr 7 | Jun 9 | Jun 16 | Aug 11 – Sep 8 | 55–70 |
| Okra | Apr 7 | Jun 9 | Jun 16 | Aug 11 – Oct 6 | 50–65 |
| Onion | Apr 28 | May 19 | Jun 2 | Sep 1 – Oct 20 | 90–120 |
| Pac Choi | Apr 28 | May 19 | Jun 2 | Jul 14 – Aug 11 | 40–55 |
| Parsnip | — | May 19 | — | Sep 1 – Oct 13 | 100–130 |
| Patty Pan Squash | Apr 28 | Jun 9 | Jun 16 | Aug 4 – Sep 1 | 45–60 |
| Peas | Apr 28 | May 19 | Jun 2 | Jul 28 – Sep 22 | 55–70 |
| Peppers | Mar 24 | Jun 9 | Jun 16 | Aug 18 – Oct 27 | 60–90 |
| Pole Beans | Apr 7 | Jun 9 | Jun 16 | Aug 11 – Oct 6 | 55–70 |
| Potatoes | Apr 7 | Jun 9 | Jun 16 | Aug 25 – Nov 3 | 70–120 |
| Pumpkin | Apr 28 | Jun 9 | Jun 16 | Sep 15 – Nov 3 | 85–120 |
| Purslane | Apr 28 | May 19 | Jun 2 | Jul 14 – Aug 18 | 40–60 |
| Radicchio | Apr 28 | May 19 | Jun 2 | Aug 4 – Sep 8 | 60–80 |
| Radish | — | May 19 | — | Jun 16 – Jul 7 | 22–35 |
| Rhubarb | — | — | Jun 23 | — | 365–730 |
| Romanesco | Apr 28 | May 19 | Jun 2 | Aug 18 – Sep 29 | 75–100 |
| Rutabaga | — | May 19 | — | Aug 11 – Sep 15 | 80–100 |
| Salsify | — | May 19 | — | Sep 1 – Oct 13 | 100–130 |
| Savoy Cabbage | Apr 28 | May 19 | Jun 2 | Aug 11 – Oct 6 | 70–110 |
| Scallions | Apr 28 | May 19 | Jun 2 | Jul 28 – Aug 25 | 50–70 |
| Scarlet Runner Beans | Apr 7 | Jun 9 | Jun 16 | Aug 18 – Sep 22 | 60–80 |
| Shallot | Apr 28 | May 19 | Jun 2 | Sep 1 – Oct 20 | 90–120 |
| Shiso | Apr 14 | Jun 9 | Jun 16 | Aug 11 – Oct 6 | 50–70 |
| Snap Peas | Apr 7 | Jun 9 | Jun 16 | Aug 11 – Oct 6 | 55–70 |
| Snow Peas | Apr 28 | May 19 | Jun 2 | Jul 28 – Sep 22 | 50–65 |
| Soybeans | — | Jun 9 | — | Sep 1 – Oct 27 | 80–120 |
| Spaghetti Squash | Apr 28 | Jun 9 | Jun 16 | Sep 15 – Oct 13 | 85–100 |
| Spinach | Apr 28 | May 19 | Jun 2 | Jul 7 – Sep 8 | 35–50 |
| Squash (Summer) | Apr 28 | Jun 9 | Jun 16 | Aug 4 – Oct 6 | 45–65 |
| Squash (Winter) | Apr 28 | Jun 9 | Jun 16 | Sep 8 – Nov 3 | 80–120 |
| Sunchoke | — | — | Jun 16 | Oct 6 – Dec 1 | 110–150 |
| Sunflower | Apr 7 | Jun 9 | Jun 16 | Aug 25 – Oct 13 | 70–100 |
| Sweet Corn | — | Jun 9 | — | Aug 11 – Sep 22 | 60–90 |
| Sweet Potatoes | Apr 7 | Jun 9 | Jun 16 | Sep 15 – Nov 3 | 90–120 |
| Tatsoi | Apr 28 | May 19 | Jun 2 | Jul 7 – Aug 11 | 35–50 |
| Tomatillo | Apr 7 | Jun 9 | Jun 16 | Aug 18 – Oct 27 | 60–85 |
| Tomatoes | Apr 7 | Jun 9 | Jun 16 | Aug 18 – Oct 27 | 60–85 |
| Turnip | — | May 19 | — | Jun 30 – Aug 4 | 40–60 |
| Watercress | Apr 28 | May 19 | Jun 2 | Jul 14 – Aug 18 | 40–60 |
| Watermelon | Apr 28 | Jun 9 | Jun 16 | Aug 25 – Oct 13 | 70–100 |
| Wax Beans | — | Jun 9 | — | Aug 4 – Sep 29 | 50–65 |
| Winter Melon | Apr 7 | Jun 9 | Jun 16 | Sep 15 – Nov 3 | 90–120 |
| Yard Long Beans | Apr 7 | Jun 9 | Jun 16 | Aug 11 – Sep 22 | 55–80 |
| Zucchini | Apr 28 | Jun 9 | Jun 16 | Aug 4 – Sep 29 | 45–60 |
🍓 Fruits to Grow in Rio Blanco County
27 fruits that grow well in Zone 5a with planting dates for Rio Blanco County.
Show all 27 fruits with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Alpine Strawberries | — | — | Jun 23 | Sep 22 – Dec 8 | 90–180 |
| Aronia | — | — | Jun 23 | — | 730–1095 |
| Blackberries | — | — | Jun 23 | — | 365–730 |
| Blueberries | — | — | Jun 23 | — | 730–1095 |
| Boysenberries | — | — | Jun 23 | — | 365–730 |
| Cantaloupe | — | — | Jun 23 | Sep 1 – Oct 6 | 70–90 |
| Che Fruit | — | — | Jun 23 | — | 1095–1825 |
| Cranberries | — | — | Jun 23 | — | 730–1095 |
| Currants | — | — | Jun 23 | — | 730–1095 |
| Elderberries | — | — | Jun 23 | — | 730–1095 |
| Goji Berries | — | — | Jun 23 | — | 730–1095 |
| Gooseberries | — | — | Jun 23 | — | 730–1095 |
| Grapes | — | — | Jun 23 | — | 730–1095 |
| Ground Cherry | — | — | Jun 23 | Sep 1 – Oct 27 | 65–80 |
| Hardy Kiwi | — | — | Jun 23 | — | 1095–1825 |
| Haskaps | — | — | Jun 23 | — | 730–1095 |
| Honeydew | — | — | Jun 23 | Sep 15 – Oct 27 | 80–110 |
| Jostaberry | — | — | Jun 23 | — | 730–1095 |
| Lingonberries | — | — | Jun 23 | — | 730–1095 |
| Medlar | — | — | Jun 23 | — | 1095–1825 |
| Mulberries | — | — | Jun 23 | — | 730–1825 |
| Pawpaw | — | — | Jun 23 | — | 1095–2555 |
| Persimmon | — | — | Jun 23 | — | 1095–2555 |
| Quince | — | — | Jun 23 | — | 1095–1825 |
| Raspberries | — | — | Jun 23 | — | 365–730 |
| Serviceberries | — | — | Jun 23 | — | 730–1095 |
| Strawberries | — | — | Jun 23 | Sep 22 – Dec 8 | 90–365 |
🌿 Herbs to Grow in Rio Blanco County
37 herbs that grow well in Zone 5a with planting dates for Rio Blanco County.
Show all 37 herbs with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Angelica | Apr 28 | May 19 | May 26 | — | 365–730 |
| Anise | Apr 28 | May 19 | May 26 | Aug 25 – Nov 10 | 90–120 |
| Basil | Apr 14 | Jun 9 | Jun 16 | Aug 11 – Oct 13 | 50–75 |
| Bee Balm | — | — | Jun 9 | Sep 8 – Nov 24 | 90–120 |
| Borage | Apr 28 | May 19 | May 26 | Jul 21 – Sep 8 | 50–60 |
| Caraway | Apr 28 | May 19 | May 26 | — | 365–450 |
| Catnip | — | — | Jun 9 | Aug 11 – Oct 13 | 60–80 |
| Chamomile | Apr 28 | May 19 | May 26 | Jul 28 – Oct 6 | 60–90 |
| Chervil | Apr 28 | May 19 | May 26 | Jul 7 – Sep 8 | 40–60 |
| Chives | — | — | Jun 9 | Aug 11 – Oct 20 | 60–90 |
| Cilantro | Apr 28 | May 19 | May 26 | Jul 7 – Sep 8 | 40–60 |
| Comfrey | — | — | Jun 9 | Aug 11 – Oct 20 | 60–90 |
| Cumin | Apr 28 | May 19 | May 26 | Sep 8 – Nov 10 | 100–120 |
| Dill | Apr 28 | May 19 | May 26 | Jul 7 – Sep 8 | 40–60 |
| Echinacea | — | — | Jun 9 | Oct 13 – Nov 24 | 120–180 |
| Epazote | Apr 14 | Jun 9 | Jun 16 | Aug 4 – Sep 29 | 45–60 |
| Fennel (herb) | Apr 28 | May 19 | May 26 | Jul 28 – Oct 6 | 60–90 |
| Feverfew | — | — | Jun 9 | Sep 8 – Nov 24 | 90–120 |
| Garlic Chives | — | — | Jun 9 | Aug 11 – Oct 20 | 60–90 |
| Horehound | — | — | Jun 9 | Aug 25 – Oct 20 | 75–90 |
| Hyssop | — | — | Jun 9 | Aug 18 – Oct 20 | 70–90 |
| Lavender | — | — | Jun 9 | Sep 8 – Nov 24 | 90–200 |
| Lemon Balm | — | — | Jun 9 | Aug 11 – Sep 29 | 60–70 |
| Lemon Thyme | — | — | Jun 9 | Aug 18 – Oct 20 | 70–90 |
| Lovage | — | — | Jun 9 | Aug 18 – Oct 20 | 70–90 |
| Mint | — | — | Jun 9 | Aug 11 – Oct 20 | 60–90 |
| Oregano | — | — | Jun 9 | Aug 11 – Oct 20 | 60–90 |
| Parsley | Apr 28 | May 19 | May 26 | Jul 28 – Sep 29 | 60–80 |
| Rue | — | — | Jun 9 | Aug 18 – Oct 20 | 70–90 |
| Sage | — | — | Jun 9 | Aug 25 – Oct 20 | 75–90 |
| Savory | — | — | Jun 9 | Aug 4 – Sep 29 | 50–70 |
| Sorrel | Apr 28 | May 19 | May 26 | Jul 7 – Sep 8 | 40–60 |
| Tarragon | — | — | Jun 9 | Aug 11 – Oct 20 | 60–90 |
| Thai Basil | Apr 14 | Jun 9 | Jun 16 | Aug 11 – Oct 13 | 50–75 |
| Thyme | — | — | Jun 9 | Aug 18 – Oct 20 | 70–90 |
| Valerian | — | — | Jun 9 | Oct 13 – Nov 24 | 120–180 |
| Yarrow | — | — | Jun 9 | Sep 8 – Nov 24 | 90–120 |
Monthly Planting Guide for Rio Blanco County
Gardening Guides & Resources
Helpful guides from The Ultimate Homestead to improve your garden in Rio Blanco County.
Frequently Asked Questions
What planting zone is Rio Blanco County, CO?
Rio Blanco County is in USDA Hardiness Zone 5a. This zone classification determines which perennial plants survive winter and sets the baseline for frost timing across the county.
When is the last frost in Rio Blanco County, CO?
Based on 31 years of NOAA weather station data, the median last spring frost in Rio Blanco County falls around June 2. In 8 out of 10 years, last frost lands between May 3 and June 20 — a 47-day window of variability. Use June 20 as your conservative safe-to-plant date for frost-sensitive crops.
When is the first fall frost in Rio Blanco County, CO?
The median first fall frost in Rio Blanco County arrives around September 17. In cold years it can arrive as early as August 30; in mild years as late as October 10. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.
How long is the growing season in Rio Blanco County?
Rio Blanco County has a frost-free growing season of approximately 107 days. Focus on short-season varieties and start warm-season crops indoors 6–8 weeks before last frost. Climate records show the growing season is trending shorter by about 2.69 days per decade.
What is the soil like in Rio Blanco County for gardening?
Rio Blanco County has predominantly Loam soil with a pH range of 6.4–7.7 and Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.
What is grown commercially in Rio Blanco County?
Rio Blanco County has commercial agriculture that includes Hay, Cattle, Wheat, Barley. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.
Is Rio Blanco County a good location for home gardening?
Rio Blanco County scores 28/100 (Challenging) on our Microclimate Index, which combines frost reliability, drought pressure, soil challenge, elevation risk, and long-term climate trend. Gardening here benefits from close attention to frost timing and season extension due to the challenging microclimate factors.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Rio Blanco County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.
Get Your Free Garden Planner →Free download. Plan your entire garden season in minutes.
