Alamosa County, CO — Planting Guide
Alamosa County is in USDA Zone 4b. The average last spring frost is May 31 and the first fall frost is September 19, giving you a growing season of approximately 111 days.
At an elevation of 8,366 ft, Alamosa County receives approximately 18.3 in of rainfall annually. Summer highs average 81°F with winter lows around 9°F. The predominant soil type is Loam.
Based on 31 years of NOAA climate station data, the last frost date here varies by 25 days year to year — ranging from May 19 in warm years to June 14 in cold years. The growing season is trending longer by about 0.79 days per decade. Alamosa County scores 43/100 (Moderate) on the Microclimate Index.
🌡️ Zone
4b (-25°F to -20°F min)
❄️ Last Frost
May 31
🍂 First Frost
September 19
📅 Growing Season
111 days
⛰️ Elevation
8,366 ft
🌧️ Annual Rainfall
18.3 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 | 1.1 in | 5 days | — | None |
| Mar | 1.5 in | 7 days | — | None |
| Apr | 1.9 in | 7 days | 2.4 in | High |
| May | 2 in | 7 days | 2.3 in | High |
| Jun | 1.5 in | 5 days | 2.8 in | High |
| Jul | 1.5 in | 5 days | 2.8 in | High |
| Aug | 1.9 in | 6 days | 2.4 in | High |
| Sep | 1.4 in | 5 days | 2.9 in | High |
| Oct | 1.6 in | 6 days | 2.7 in | High |
| Nov | 1.6 in | 6 days | — | None |
| Dec | 1 in | 6 days | — | None |
Annual total: 18.3 in. Water needs vary by crop — tomatoes need ~1.2"/week while herbs like rosemary need only 0.3"/week. Check individual plant pages for crop-specific water budgets that factor in your county's rainfall and soil drainage.
Alamosa County Soil Profile
Soil Type
Loam
Soil pH
6.4-8
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 14 | Sep 30 | 108 days |
| Cautious | Jun 9 | Sep 23 | 106 days |
| Average year | May 31 | Sep 19 | 111 days |
| Optimistic | May 26 | Sep 13 | 110 days |
| Aggressive (risky) | May 19 | Sep 7 | 111 days |
Not very — frost dates can vary by ±25 days year-to-year. Use the "Conservative" row in the table below, and keep row covers handy for surprise late frosts.
Slightly — seasons are trending a bit longer (0.8 days/decade). Historical frost dates are still reliable for planning.
Gardening Difficulty Score
Alamosa County presents some gardening challenges. Choose adapted varieties and plan around frost dates.
Local Gardening Help in Alamosa 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 Alamosa County's climate and soil.
County Extension Office
Alamosa 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 Alamosa County
Finding local nurseries & garden centers in Alamosa County
Why Buy Local
Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Alamosa 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 Alamosa County CO" or "garden center Alamosa 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 Alamosa County CO" or check your extension office and local parks department. Facebook groups like "Alamosa 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
14.6 hours
Summer solstice daylight
Shortest Day
9.4 hours
Winter solstice daylight
Peak Sun Hours
10.1 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 | 9.7 hr | 5.3 hr | Short day |
| February | 10.6 hr | 6.1 hr | Short day |
| March | 11.7 hr | 6.9 hr | Short day |
| April | 13 hr | 7.3 hr | Neutral |
| May | 14 hr | 8.3 hr | Long day |
| June | 14.6 hr | 10.1 hr | Long day |
| July | 14.4 hr | 9.8 hr | Long day |
| August | 13.4 hr | 9 hr | Neutral |
| September | 12.2 hr | 8.1 hr | Neutral |
| October | 11 hr | 7.1 hr | Short day |
| November | 9.9 hr | 5.9 hr | Short day |
| December | 9.4 hr | 5.3 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
Apr
Microbial activity peaks when soil is warm.
Active Composting
0 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 | -11°F | -1°F | ❄️ Dormant | ~36 weeks |
| Feb | -9°F | -3°F | ❄️ Dormant | ~36 weeks |
| Mar | -0°F | 3°F | ❄️ Dormant | ~36 weeks |
| Apr | 15°F | 14°F | ❄️ Dormant | ~36 weeks |
| May | 28°F | 26°F | ❄️ Dormant | ~36 weeks |
| Jun | 41°F | 35°F | 🐢 Slow | ~24 weeks |
| Jul | 46°F | 41°F | 🐢 Slow | ~24 weeks |
| Aug | 48°F | 44°F | 🐢 Slow | ~24 weeks |
| Sep | 40°F | 39°F | ❄️ Dormant | ~36 weeks |
| Oct | 27°F | 31°F | ❄️ Dormant | ~36 weeks |
| Nov | 14°F | 19°F | ❄️ Dormant | ~36 weeks |
| Dec | -4°F | 6°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 Alamosa 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 |
| Cabbage worms | Low | Jun, Jul, Aug |
| Colorado potato beetle | Low | Jun, Jul |
| Flea beetles | Low | May, Jun, Jul |
| Slugs | Low | May, Jun, Jul, Aug, Sep |
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 Alamosa County
Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with county-specific planting dates.
Spring Cover Crops (2 options) — Build soil before the main growing season
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Buckwheat | Jun 4 | Jul 18 | — | Rapid growth, attracts pollinators, suppresses weeds |
| White clover | May 3 | Jul 11 | ✓ 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 14 | Aug 29 | — | Deep roots break compaction, attract pollinators and beneficial insects |
Fall Cover Crops (5 options) — Plant after harvest to protect soil over winter
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Daikon radish | Aug 9 | May 17 | — | Deep taproot breaks compaction, excellent for clay soils |
| Hairy vetch | Jul 7 | May 17 | ✓ Yes | Excellent nitrogen fixer, good for depleted soils |
| Oats | Aug 13 | May 10 | — | Quick biomass, winterkills in cold zones — no spring tillage needed |
| Winter rye | Jun 27 | May 10 | — | Suppresses weeds, prevents erosion, breaks up compacted soil |
| Winter wheat | Jun 18 | May 17 | — | Erosion control, weed suppression, good biomass |
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: 11 mph
Fall: 12 mph Winter: 14 mph
Prevailing wind: W. Windy area — plant a windbreak hedge on the W side of your garden.
Windbreak Benefit
6.6/10
Moderately beneficial — a simple fence or trellis can protect delicate crops from wind stress.
Frost Pocket Risk
Moderate
Some terrain variation (938 ft range). Garden on slopes or higher ground if possible to avoid late-season frost pockets.
Rainwater Harvesting Potential
How much water you can collect, when to collect it, and what size system you need for your garden.
Annual Collection
9,120 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
Apr, May, Aug, Oct
Highest rainfall months — your barrels will fill up quickly during these months.
Months to Draw From Storage
Jan, Feb, 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 18.3 inches of rain per year
- A 1,000 sq ft roof can collect roughly 9,120 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 Alamosa County
Soil Type
Loam
Soil pH 6.4–8 · Well Drained drainage
Good candidate for raised beds to maximise drainage and extend the season.
Watering Needs
Drought stress: 5.5/10
Moderate drought pressure. Drip irrigation and mulching are highly recommended to maintain soil moisture through summer.
Season Tips
111-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 Alamosa County
96 vegetables that grow well in Zone 4b with planting dates for Alamosa County.
Show all 96 vegetables with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Acorn Squash | Apr 19 | Jun 14 | Jun 21 | Sep 13 – Oct 18 | 80–100 |
| Amaranth | Mar 29 | Jun 14 | Jun 21 | Sep 20 – Nov 8 | 90–120 |
| Arugula | Apr 19 | May 24 | May 31 | Jul 5 – Sep 6 | 30–50 |
| Asparagus | — | — | Jun 14 | — | 730–1095 |
| Beets | — | May 24 | — | Jul 19 – Aug 16 | 50–70 |
| Belgian Endive | Apr 19 | May 24 | May 31 | Sep 20 – Oct 25 | 110–150 |
| Black Beans | — | Jun 14 | — | Sep 13 – Nov 1 | 90–120 |
| Bok Choy | Apr 19 | May 24 | May 31 | Jul 12 – Aug 16 | 40–60 |
| Broccoli | Apr 19 | May 24 | May 31 | Aug 2 – Sep 13 | 60–90 |
| Broccoli Rabe | Apr 19 | May 24 | May 31 | Jul 12 – Aug 16 | 40–60 |
| Brussels Sprouts | Apr 19 | May 24 | May 31 | Aug 30 – Oct 25 | 90–130 |
| Butternut Squash | Apr 19 | Jun 14 | Jun 21 | Sep 20 – Oct 25 | 85–110 |
| Cabbage | Apr 19 | May 24 | May 31 | Aug 2 – Sep 27 | 60–100 |
| Carrots | — | May 24 | — | Jul 26 – Aug 30 | 60–80 |
| Cauliflower | Apr 19 | May 24 | May 31 | Jul 26 – Sep 27 | 55–100 |
| Celeriac | Apr 19 | May 24 | May 31 | Sep 13 – Oct 18 | 100–120 |
| Celery | Apr 19 | May 24 | May 31 | Aug 23 – Oct 18 | 80–120 |
| Celtuce | Apr 19 | May 24 | May 31 | Aug 2 – Sep 13 | 60–90 |
| Chard | Apr 19 | May 24 | May 31 | Jul 26 – Sep 13 | 50–60 |
| Chickpeas | Apr 19 | May 24 | May 31 | Aug 23 – Oct 4 | 80–110 |
| Chicory | Apr 19 | May 24 | May 31 | Aug 2 – Sep 13 | 60–85 |
| Chinese Cabbage | Apr 19 | May 24 | May 31 | Jul 26 – Aug 23 | 50–70 |
| Christmas Lima Beans | Mar 29 | Jun 14 | Jun 21 | Sep 13 – Oct 18 | 80–100 |
| Collard Greens | Apr 19 | May 24 | May 31 | Jul 26 – Sep 27 | 55–75 |
| Corn | — | Jun 14 | — | Aug 16 – Oct 11 | 60–100 |
| Cress | Apr 19 | May 24 | May 31 | Jun 14 – Jul 5 | 14–21 |
| Crookneck Squash | Apr 19 | Jun 14 | Jun 21 | Aug 9 – Sep 6 | 45–60 |
| Crosne | — | May 24 | — | Oct 25 – Oct 18 | 150–200 |
| Cucumber | Apr 19 | Jun 14 | Jun 21 | Aug 16 – Oct 11 | 50–70 |
| Daikon | — | May 24 | — | Jul 19 – Aug 16 | 50–70 |
| Delicata Squash | Apr 19 | Jun 14 | Jun 21 | Sep 13 – Oct 18 | 80–100 |
| Edamame | — | Jun 14 | — | Aug 30 – Oct 11 | 75–100 |
| Endive | Apr 19 | May 24 | May 31 | Jul 19 – Aug 23 | 45–65 |
| Escarole | Apr 19 | May 24 | May 31 | Jul 26 – Aug 23 | 50–70 |
| Fava Beans | Apr 19 | May 24 | May 31 | Aug 16 – Sep 27 | 75–100 |
| Fennel | Mar 29 | Jun 14 | Jun 21 | Aug 23 – Oct 4 | 60–90 |
| Garlic | — | — | — | — | 90–240 |
| Green Beans | — | Jun 14 | — | Aug 9 – Oct 4 | 50–65 |
| Horseradish | — | — | Jun 14 | Oct 18 – Nov 8 | 120–180 |
| Hubbard Squash | Apr 19 | Jun 14 | Jun 21 | Oct 4 – Nov 8 | 100–120 |
| Kabocha | Apr 19 | Jun 14 | Jun 21 | Sep 20 – Oct 18 | 85–100 |
| Kai Lan | Apr 19 | May 24 | May 31 | Jul 19 – Aug 16 | 45–60 |
| Kale | Apr 19 | May 24 | May 31 | Jul 26 – Sep 20 | 50–70 |
| Kidney Beans | — | Jun 14 | — | Sep 13 – Oct 18 | 85–110 |
| Kohlrabi | Apr 19 | May 24 | May 31 | Jul 19 – Aug 23 | 45–65 |
| Komatsuna | Apr 19 | May 24 | May 31 | Jul 5 – Aug 9 | 35–50 |
| Leeks | Apr 19 | May 24 | May 31 | Aug 30 – Oct 25 | 90–150 |
| Lentils | Apr 19 | May 24 | May 31 | Aug 23 – Oct 4 | 80–110 |
| Lettuce | Apr 19 | May 24 | May 31 | Jul 5 – Sep 13 | 30–60 |
| Lima Beans | — | Jun 14 | — | Aug 16 – Sep 27 | 60–90 |
| Mache | Apr 19 | May 24 | May 31 | Jul 12 – Aug 16 | 40–60 |
| Melon | Apr 19 | Jun 14 | Jun 21 | Aug 30 – Oct 18 | 70–100 |
| Microgreens | Apr 19 | May 24 | May 31 | Jun 7 – Jul 5 | 7–21 |
| Mitsuba | Apr 19 | May 24 | May 24 | Jul 19 – Sep 13 | 50–70 |
| Mizuna | Apr 19 | May 24 | May 31 | Jul 5 – Aug 2 | 30–45 |
| Mustard Greens | Apr 19 | May 24 | May 31 | Jul 5 – Sep 6 | 30–50 |
| Napa Cabbage | Apr 19 | May 24 | May 31 | Jul 26 – Aug 30 | 55–75 |
| Onion | Apr 19 | May 24 | May 31 | Aug 30 – Oct 18 | 90–120 |
| Pac Choi | Apr 19 | May 24 | May 31 | Jul 12 – Aug 9 | 40–55 |
| Parsnip | — | May 24 | — | Sep 6 – Oct 18 | 100–130 |
| Patty Pan Squash | Apr 19 | Jun 14 | Jun 21 | Aug 9 – Sep 6 | 45–60 |
| Peas | Apr 19 | May 24 | May 31 | Jul 26 – Sep 20 | 55–70 |
| Peppers | Mar 15 | Jun 14 | Jun 21 | Aug 23 – Nov 1 | 60–90 |
| Pole Beans | Mar 29 | Jun 14 | Jun 21 | Aug 16 – Oct 11 | 55–70 |
| Potatoes | Mar 29 | Jun 14 | Jun 21 | Aug 30 – Nov 8 | 70–120 |
| Pumpkin | Apr 19 | Jun 14 | Jun 21 | Sep 20 – Nov 8 | 85–120 |
| Purslane | Apr 19 | May 24 | May 31 | Jul 12 – Aug 16 | 40–60 |
| Radicchio | Apr 19 | May 24 | May 31 | Aug 2 – Sep 6 | 60–80 |
| Radish | — | May 24 | — | Jun 21 – Jul 12 | 22–35 |
| Rhubarb | — | — | Jun 28 | — | 365–730 |
| Romanesco | Apr 19 | May 24 | May 31 | Aug 16 – Sep 27 | 75–100 |
| Rutabaga | — | May 24 | — | Aug 16 – Sep 20 | 80–100 |
| Salsify | — | May 24 | — | Sep 6 – Oct 18 | 100–130 |
| Savoy Cabbage | Apr 19 | May 24 | May 31 | Aug 9 – Oct 4 | 70–110 |
| Scallions | Apr 19 | May 24 | May 31 | Jul 26 – Aug 23 | 50–70 |
| Scarlet Runner Beans | Mar 29 | Jun 14 | Jun 21 | Aug 23 – Sep 27 | 60–80 |
| Shallot | Apr 19 | May 24 | May 31 | Aug 30 – Oct 18 | 90–120 |
| Shiso | Apr 5 | Jun 7 | Jun 21 | Aug 16 – Oct 11 | 50–70 |
| Snap Peas | Mar 29 | Jun 14 | Jun 21 | Aug 16 – Oct 11 | 55–70 |
| Snow Peas | Apr 19 | May 24 | May 31 | Jul 26 – Sep 20 | 50–65 |
| Soybeans | — | Jun 14 | — | Sep 6 – Nov 1 | 80–120 |
| Spaghetti Squash | Apr 19 | Jun 14 | Jun 21 | Sep 20 – Oct 18 | 85–100 |
| Spinach | Apr 19 | May 24 | May 31 | Jul 5 – Sep 6 | 35–50 |
| Squash (Summer) | Apr 19 | Jun 14 | Jun 21 | Aug 9 – Oct 11 | 45–65 |
| Squash (Winter) | Apr 19 | Jun 14 | Jun 21 | Sep 13 – Nov 8 | 80–120 |
| Sunchoke | — | — | Jun 14 | Oct 4 – Nov 8 | 110–150 |
| Sunflower | Mar 29 | Jun 14 | Jun 21 | Aug 30 – Oct 18 | 70–100 |
| Sweet Corn | — | Jun 14 | — | Aug 16 – Sep 27 | 60–90 |
| Tatsoi | Apr 19 | May 24 | May 31 | Jul 5 – Aug 9 | 35–50 |
| Tomatillo | Mar 29 | Jun 14 | Jun 21 | Aug 23 – Nov 1 | 60–85 |
| Tomatoes | Mar 29 | Jun 14 | Jun 21 | Aug 23 – Nov 1 | 60–85 |
| Turnip | — | May 24 | — | Jul 5 – Aug 9 | 40–60 |
| Watercress | Apr 19 | May 24 | May 31 | Jul 12 – Aug 16 | 40–60 |
| Watermelon | Apr 19 | Jun 14 | Jun 21 | Aug 30 – Oct 18 | 70–100 |
| Wax Beans | — | Jun 14 | — | Aug 9 – Oct 4 | 50–65 |
| Zucchini | Apr 19 | Jun 14 | Jun 21 | Aug 9 – Oct 4 | 45–60 |
🍓 Fruits to Grow in Alamosa County
22 fruits that grow well in Zone 4b with planting dates for Alamosa County.
Show all 22 fruits with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Alpine Strawberries | — | — | Jun 28 | Sep 27 – Nov 22 | 90–180 |
| Aronia | — | — | Jun 28 | — | 730–1095 |
| Blueberries | — | — | Jun 28 | — | 730–1095 |
| Cantaloupe | — | — | Jun 28 | Sep 6 – Oct 11 | 70–90 |
| Cranberries | — | — | Jun 28 | — | 730–1095 |
| Currants | — | — | Jun 28 | — | 730–1095 |
| Elderberries | — | — | Jun 28 | — | 730–1095 |
| Goji Berries | — | — | Jun 28 | — | 730–1095 |
| Gooseberries | — | — | Jun 28 | — | 730–1095 |
| Grapes | — | — | Jun 28 | — | 730–1095 |
| Ground Cherry | — | — | Jun 28 | Sep 6 – Nov 1 | 65–80 |
| Hardy Kiwi | — | — | Jun 28 | — | 1095–1825 |
| Haskaps | — | — | Jun 28 | — | 730–1095 |
| Honeydew | — | — | Jun 28 | Sep 20 – Nov 1 | 80–110 |
| Jostaberry | — | — | Jun 28 | — | 730–1095 |
| Lingonberries | — | — | Jun 28 | — | 730–1095 |
| Medlar | — | — | Jun 28 | — | 1095–1825 |
| Mulberries | — | — | Jun 28 | — | 730–1825 |
| Persimmon | — | — | Jun 28 | — | 1095–2555 |
| Raspberries | — | — | Jun 28 | — | 365–730 |
| Serviceberries | — | — | Jun 28 | — | 730–1095 |
| Strawberries | — | — | Jun 28 | Sep 27 – Nov 22 | 90–365 |
🌿 Herbs to Grow in Alamosa County
32 herbs that grow well in Zone 4b with planting dates for Alamosa County.
Show all 32 herbs with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Angelica | Apr 19 | May 24 | May 24 | — | 365–730 |
| Anise | Apr 19 | May 24 | May 24 | Aug 23 – Oct 18 | 90–120 |
| Basil | Apr 5 | Jun 7 | Jun 21 | Aug 16 – Oct 18 | 50–75 |
| Bee Balm | — | — | Jun 7 | Sep 6 – Nov 1 | 90–120 |
| Borage | Apr 19 | May 24 | May 24 | Jul 19 – Sep 6 | 50–60 |
| Caraway | Apr 19 | May 24 | May 24 | — | 365–450 |
| Catnip | — | — | Jun 7 | Aug 9 – Oct 11 | 60–80 |
| Chamomile | Apr 19 | May 24 | May 24 | Jul 26 – Oct 4 | 60–90 |
| Chervil | Apr 19 | May 24 | May 24 | Jul 5 – Sep 6 | 40–60 |
| Chives | — | — | Jun 7 | Aug 9 – Oct 18 | 60–90 |
| Cilantro | Apr 19 | May 24 | May 24 | Jul 5 – Sep 6 | 40–60 |
| Comfrey | — | — | Jun 7 | Aug 9 – Oct 18 | 60–90 |
| Dill | Apr 19 | May 24 | May 24 | Jul 5 – Sep 6 | 40–60 |
| Echinacea | — | — | Jun 7 | Oct 11 – Nov 1 | 120–180 |
| Fennel (herb) | Apr 19 | May 24 | May 24 | Jul 26 – Oct 4 | 60–90 |
| Garlic Chives | — | — | Jun 7 | Aug 9 – Oct 18 | 60–90 |
| Horehound | — | — | Jun 7 | Aug 23 – Oct 18 | 75–90 |
| Hyssop | — | — | Jun 7 | Aug 16 – Oct 18 | 70–90 |
| Lemon Balm | — | — | Jun 7 | Aug 9 – Sep 27 | 60–70 |
| Lovage | — | — | Jun 7 | Aug 16 – Oct 18 | 70–90 |
| Mint | — | — | Jun 7 | Aug 9 – Oct 18 | 60–90 |
| Oregano | — | — | Jun 7 | Aug 9 – Oct 18 | 60–90 |
| Parsley | Apr 19 | May 24 | May 24 | Jul 26 – Sep 27 | 60–80 |
| Rue | — | — | Jun 7 | Aug 16 – Oct 18 | 70–90 |
| Sage | — | — | Jun 7 | Aug 23 – Oct 18 | 75–90 |
| Savory | — | — | Jun 7 | Aug 2 – Sep 27 | 50–70 |
| Sorrel | Apr 19 | May 24 | May 24 | Jul 5 – Sep 6 | 40–60 |
| Tarragon | — | — | Jun 7 | Aug 9 – Oct 18 | 60–90 |
| Thai Basil | Apr 5 | Jun 7 | Jun 21 | Aug 16 – Oct 18 | 50–75 |
| Thyme | — | — | Jun 7 | Aug 16 – Oct 18 | 70–90 |
| Valerian | — | — | Jun 7 | Oct 11 – Nov 1 | 120–180 |
| Yarrow | — | — | Jun 7 | Sep 6 – Nov 1 | 90–120 |
Monthly Planting Guide for Alamosa County
Gardening Guides & Resources
Helpful guides from The Ultimate Homestead to improve your garden in Alamosa County.
Frequently Asked Questions
What planting zone is Alamosa County, CO?
Alamosa County is in USDA Hardiness Zone 4b. 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 Alamosa County, CO?
Based on 31 years of NOAA weather station data, the median last spring frost in Alamosa County falls around May 31. In 8 out of 10 years, last frost lands between May 19 and June 14 — a 25-day window of variability. Use June 14 as your conservative safe-to-plant date for frost-sensitive crops.
When is the first fall frost in Alamosa County, CO?
The median first fall frost in Alamosa County arrives around September 19. In cold years it can arrive as early as September 7; in mild years as late as September 30. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.
How long is the growing season in Alamosa County?
Alamosa County has a frost-free growing season of approximately 111 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 longer by about 0.79 days per decade.
What is the soil like in Alamosa County for gardening?
Alamosa County has predominantly Loam soil with a pH range of 6.4–8 and Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.
What is grown commercially in Alamosa County?
Alamosa County has commercial agriculture that includes Cattle, Hay, 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 Alamosa County a good location for home gardening?
Alamosa County scores 43/100 (Moderate) 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 Alamosa County gardeners in Zone 4b 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.
