Blog

Pitkin County, CO — Planting Guide

Pitkin County is in USDA Zone 4a. The average last spring frost is June 16 and the first fall frost is September 7, giving you a growing season of approximately 83 days.

At an elevation of 6,411 ft, Pitkin County receives approximately 17.8 in of rainfall annually. Summer highs average 82°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 47 days year to year — ranging from May 11 in warm years to June 27 in cold years. The growing season is trending shorter by about 1.74 days per decade. Pitkin County scores 36/100 (Challenging) on the Microclimate Index.

🌡️ Zone

4a (-30°F to -25°F min)

❄️ Last Frost

June 16

🍂 First Frost

September 7

📅 Growing Season

83 days

⛰️ Elevation

6,411 ft

🌧️ Annual Rainfall

17.8 in

Pitkin County, CO Very short season
83 days
Last Spring Frost June 16
83 growing days
First Fall Frost September 7

Monthly Watering Calendar

When you'll need to water your garden — based on average monthly rainfall vs. the ~1 inch/week most gardens need.

1"/wk 0" 1.3" 2.5" 3.8" 5" Jan 1.3" Feb 1" Mar 1.7" +2.4" Apr 1.9" +2.3" May 2" +3" Jun 1.3" +2.9" Jul 1.4" +2.4" Aug 1.9" +2.6" Sep 1.7" +2.8" Oct 1.5" Nov 1.1" Dec 0.9"
Rainfall sufficient Supplemental water needed Heavy watering required - - - 1"/week garden need
View detailed monthly data
MonthAvg RainfallRainy DaysExtra Water NeededWatering Effort
Jan 1.3 in 7 days None
Feb 1 in 5 days None
Mar 1.7 in 7 days None
Apr 1.9 in 7 days 2.4 in High
May 2 in 8 days 2.3 in High
Jun 1.3 in 5 days 3 in High
Jul 1.4 in 6 days 2.9 in High
Aug 1.9 in 7 days 2.4 in High
Sep 1.7 in 6 days 2.6 in High
Oct 1.5 in 6 days 2.8 in High
Nov 1.1 in 6 days None
Dec 0.9 in 7 days None

Annual total: 17.7 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.

Pitkin County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.3

Drainage

Well Drained

Frost Risk Probability

Based on 31 years of NOAA weather station data from 3 stations

Too early frost risk Safe to Plant Jun 16 → Sep 7 83 frost-free days Protect crops frost returns May Jun Jul Aug Sep Oct Nov Safe: Jun 27 Protect by: Oct 7

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 27 Oct 7 102 days
Cautious Jun 23 Sep 14 83 days
Average year Jun 16 Sep 7 83 days
Optimistic Jun 5 Aug 27 83 days
Aggressive (risky) May 11 Aug 14 95 days
📊
How predictable are frost dates here?

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.

⚠️
Is the growing season changing?

Yes — growing seasons are getting shorter here (about 1.7 days per decade). Use the "Conservative" dates and choose fast-maturing varieties.

Gardening Difficulty Score

36 Challenging
Frost Timing Risk
10.0/10
Drought Risk
5.5/10
Soil Difficulty
1.0/10
Altitude Challenge
10.0/10
Climate Shift
7.0/10
Rainfall Challenge
4.9/10

Pitkin County has challenging growing conditions. Season extension and careful variety selection are essential.

Zone 4a Frost Countdown
--
Loading...
Last Frost: Jun 16 First Frost: Sep 7

Local Gardening Help in Pitkin 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 Pitkin County's climate and soil.

County Extension Office

Pitkin 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.

Find Master Gardeners in CO →

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.

Request a Soil Test →

Services Available in Pitkin County

Soil testing High-altitude gardening Water conservation Pest diagnostics
Finding local nurseries & garden centers in Pitkin County

Why Buy Local

Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Pitkin 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 Pitkin County CO" or "garden center Pitkin 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 Pitkin County CO" or check your extension office and local parks department. Facebook groups like "Pitkin 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.

After Radish (harvest ends Aug 4) 34 days until frost

Sunlight & Day Length

Monthly daylight hours and peak sun — critical for onion varieties, photoperiod-sensitive plants, and solar garden planning.

Longest Day

14.7 hours

Summer solstice daylight

Shortest Day

9.3 hours

Winter solstice daylight

Peak Sun Hours

10.5 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.

14hr 12hr 4h 7h 10h 13h 16h Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Daylight hours (sunrise to sunset) Peak sun hours (direct sunlight after cloud cover) ▪ Gold zone = long day (14+ hr) ▪ Blue zone = short day (<12 hr)

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
MonthDaylight HoursPeak Sun HoursDay Length
January 9.5 hr 5.3 hr Short day
February 10.5 hr 6.3 hr Short day
March 11.7 hr 7 hr Short day
April 13 hr 7.2 hr Neutral
May 14.1 hr 9 hr Long day
June 14.7 hr 10.5 hr Long day
July 14.5 hr 10.1 hr Long day
August 13.5 hr 9 hr Neutral
September 12.2 hr 8.5 hr Neutral
October 10.9 hr 7.3 hr Short day
November 9.8 hr 5.8 hr Short day
December 9.3 hr 5.2 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.

60°F 18° 35° 53° 70° Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
4" depth 8" depth - - - 60°F (corn, beans) - - - 70°F (tomatoes, peppers)
View detailed monthly data
MonthSoil 4" DeepSoil 8" DeepCompost ActivityTime to Finish
Jan -3°F 7°F ❄️ Dormant ~36 weeks
Feb -2°F 4°F ❄️ Dormant ~36 weeks
Mar 9°F 10°F ❄️ Dormant ~36 weeks
Apr 23°F 21°F ❄️ Dormant ~36 weeks
May 36°F 33°F ❄️ Dormant ~36 weeks
Jun 48°F 42°F 🐢 Slow ~24 weeks
Jul 53°F 49°F ♻️ Active ~14 weeks
Aug 56°F 52°F ♻️ Active ~14 weeks
Sep 49°F 47°F 🐢 Slow ~24 weeks
Oct 33°F 37°F ❄️ Dormant ~36 weeks
Nov 18°F 25°F ❄️ Dormant ~36 weeks
Dec 3°F 14°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 Pitkin County

Computed from local climate patterns — warmer, humid conditions increase pest generations and fungal disease risk.

Insect Pest Pressure

4.3 / 10

Moderate — common pests appear but manageable with monitoring.

Disease Risk

2.4 / 10

Low disease risk — dry conditions reduce fungal problems.

Seasonal Risk

Spring Low
Summer High
Fall Low
Winter Low
View 5 common pests in your area
PestRisk LevelPeak Months
Aphids Moderate May, Jun, Jul, Aug
Cabbage worms Low Jun, Jul, Aug
Colorado potato beetle Moderate 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 Pitkin County

Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with county-specific planting dates.

Fall Cover Crops (5 options) — Plant after harvest to protect soil over winter
Crop Plant By Terminate N-Fixing Soil Benefit
Daikon radish Jul 13 May 26 Deep taproot breaks compaction, excellent for clay soils
Hairy vetch Jun 29 May 26 ✓ Yes Excellent nitrogen fixer, good for depleted soils
Oats Aug 11 Jun 2 Quick biomass, winterkills in cold zones — no spring tillage needed
Winter rye Jun 9 May 26 Suppresses weeds, prevents erosion, breaks up compacted soil
Winter wheat Jun 8 May 26 Erosion control, weed suppression, good biomass
Spring Cover Crops (2 options) — Build soil before the main growing season
Crop Plant By Terminate N-Fixing Soil Benefit
Buckwheat Jun 25 Jul 6 Rapid growth, attracts pollinators, suppresses weeds
White clover May 20 Jul 13 ✓ 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 Jul 8 Aug 24 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: 12 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

7.3/10

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 1,597 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

8,821 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 1,000 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

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 17.7 inches of rain per year
  • A 1,000 sq ft roof can collect roughly 8,821 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 Pitkin County

Soil Type

Loam

Soil pH 6.6–8.3 · 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

83-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.

Get My Free Planner →

Recommended for Your Garden

🧪
Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

📏
Digital pH Meter $10-20

Get instant, accurate soil pH readings to fine-tune your amendments.

🍂
Organic Compost $8-30

Boost soil fertility and structure with rich, well-aged organic compost.

🥬 Vegetables to Grow in Pitkin County

96 vegetables that grow well in Zone 4a with planting dates for Pitkin County.

Show all 96 vegetables with planting dates
Plant Start Indoors Direct Sow Transplant Harvest Days to Maturity
Acorn Squash May 5 Jun 30 Jul 7 Sep 29 – Nov 3 80–100
Amaranth Apr 14 Jun 30 Jul 7 Oct 6 – Nov 24 90–120
Arugula May 5 Jun 9 Jun 16 Jul 21 – Sep 22 30–50
Asparagus Jun 30 730–1095
Beets Jun 9 Aug 4 – Sep 1 50–70
Belgian Endive May 5 Jun 9 Jun 16 Oct 6 – Nov 10 110–150
Black Beans Jun 30 Sep 29 – Nov 17 90–120
Bok Choy May 5 Jun 9 Jun 16 Jul 28 – Sep 1 40–60
Broccoli May 5 Jun 9 Jun 16 Aug 18 – Sep 29 60–90
Broccoli Rabe May 5 Jun 9 Jun 16 Jul 28 – Sep 1 40–60
Brussels Sprouts May 5 Jun 9 Jun 16 Sep 15 – Nov 10 90–130
Butternut Squash May 5 Jun 30 Jul 7 Oct 6 – Nov 10 85–110
Cabbage May 5 Jun 9 Jun 16 Aug 18 – Oct 13 60–100
Carrots Jun 9 Aug 11 – Sep 15 60–80
Cauliflower May 5 Jun 9 Jun 16 Aug 11 – Oct 13 55–100
Celeriac May 5 Jun 9 Jun 16 Sep 29 – Nov 3 100–120
Celery May 5 Jun 9 Jun 16 Sep 8 – Nov 3 80–120
Celtuce May 5 Jun 9 Jun 16 Aug 18 – Sep 29 60–90
Chard May 5 Jun 9 Jun 16 Aug 11 – Sep 29 50–60
Chickpeas May 5 Jun 9 Jun 16 Sep 8 – Oct 20 80–110
Chicory May 5 Jun 9 Jun 16 Aug 18 – Sep 29 60–85
Chinese Cabbage May 5 Jun 9 Jun 16 Aug 11 – Sep 8 50–70
Christmas Lima Beans Apr 14 Jun 30 Jul 7 Sep 29 – Nov 3 80–100
Collard Greens May 5 Jun 9 Jun 16 Aug 11 – Oct 13 55–75
Corn Jun 30 Sep 1 – Oct 27 60–100
Cress May 5 Jun 9 Jun 16 Jun 30 – Jul 21 14–21
Crookneck Squash May 5 Jun 30 Jul 7 Aug 25 – Sep 22 45–60
Crosne Jun 9 Nov 10 – Nov 3 150–200
Cucumber May 5 Jun 30 Jul 7 Sep 1 – Oct 27 50–70
Daikon Jun 9 Aug 4 – Sep 1 50–70
Delicata Squash May 5 Jun 30 Jul 7 Sep 29 – Nov 3 80–100
Edamame Jun 30 Sep 15 – Oct 27 75–100
Endive May 5 Jun 9 Jun 16 Aug 4 – Sep 8 45–65
Escarole May 5 Jun 9 Jun 16 Aug 11 – Sep 8 50–70
Fava Beans May 5 Jun 9 Jun 16 Sep 1 – Oct 13 75–100
Fennel Apr 14 Jun 30 Jul 7 Sep 8 – Oct 20 60–90
Garlic 90–240
Green Beans Jun 30 Aug 25 – Oct 20 50–65
Horseradish Jun 30 Nov 3 – Nov 24 120–180
Hubbard Squash May 5 Jun 30 Jul 7 Oct 20 – Nov 24 100–120
Kabocha May 5 Jun 30 Jul 7 Oct 6 – Nov 3 85–100
Kai Lan May 5 Jun 9 Jun 16 Aug 4 – Sep 1 45–60
Kale May 5 Jun 9 Jun 16 Aug 11 – Oct 6 50–70
Kidney Beans Jun 30 Sep 29 – Nov 3 85–110
Kohlrabi May 5 Jun 9 Jun 16 Aug 4 – Sep 8 45–65
Komatsuna May 5 Jun 9 Jun 16 Jul 21 – Aug 25 35–50
Leeks May 5 Jun 9 Jun 16 Sep 15 – Nov 10 90–150
Lentils May 5 Jun 9 Jun 16 Sep 8 – Oct 20 80–110
Lettuce May 5 Jun 9 Jun 16 Jul 21 – Sep 29 30–60
Lima Beans Jun 30 Sep 1 – Oct 13 60–90
Mache May 5 Jun 9 Jun 16 Jul 28 – Sep 1 40–60
Melon May 5 Jun 30 Jul 7 Sep 15 – Nov 3 70–100
Microgreens May 5 Jun 9 Jun 16 Jun 23 – Jul 21 7–21
Mitsuba May 5 Jun 9 Jun 9 Aug 4 – Sep 29 50–70
Mizuna May 5 Jun 9 Jun 16 Jul 21 – Aug 18 30–45
Mustard Greens May 5 Jun 9 Jun 16 Jul 21 – Sep 22 30–50
Napa Cabbage May 5 Jun 9 Jun 16 Aug 11 – Sep 15 55–75
Onion May 5 Jun 9 Jun 16 Sep 15 – Nov 3 90–120
Pac Choi May 5 Jun 9 Jun 16 Jul 28 – Aug 25 40–55
Parsnip Jun 9 Sep 22 – Nov 3 100–130
Patty Pan Squash May 5 Jun 30 Jul 7 Aug 25 – Sep 22 45–60
Peas May 5 Jun 9 Jun 16 Aug 11 – Oct 6 55–70
Peppers Mar 31 Jun 30 Jul 7 Sep 8 – Nov 17 60–90
Pole Beans Apr 14 Jun 30 Jul 7 Sep 1 – Oct 27 55–70
Potatoes Apr 14 Jun 30 Jul 7 Sep 15 – Nov 24 70–120
Pumpkin May 5 Jun 30 Jul 7 Oct 6 – Nov 24 85–120
Purslane May 5 Jun 9 Jun 16 Jul 28 – Sep 1 40–60
Radicchio May 5 Jun 9 Jun 16 Aug 18 – Sep 22 60–80
Radish Jun 9 Jul 7 – Jul 28 22–35
Rhubarb Jul 14 365–730
Romanesco May 5 Jun 9 Jun 16 Sep 1 – Oct 13 75–100
Rutabaga Jun 9 Sep 1 – Oct 6 80–100
Salsify Jun 9 Sep 22 – Nov 3 100–130
Savoy Cabbage May 5 Jun 9 Jun 16 Aug 25 – Oct 20 70–110
Scallions May 5 Jun 9 Jun 16 Aug 11 – Sep 8 50–70
Scarlet Runner Beans Apr 14 Jun 30 Jul 7 Sep 8 – Oct 13 60–80
Shallot May 5 Jun 9 Jun 16 Sep 15 – Nov 3 90–120
Shiso Apr 21 Jun 23 Jul 7 Sep 1 – Oct 27 50–70
Snap Peas Apr 14 Jun 30 Jul 7 Sep 1 – Oct 27 55–70
Snow Peas May 5 Jun 9 Jun 16 Aug 11 – Oct 6 50–65
Soybeans Jun 30 Sep 22 – Nov 17 80–120
Spaghetti Squash May 5 Jun 30 Jul 7 Oct 6 – Nov 3 85–100
Spinach May 5 Jun 9 Jun 16 Jul 21 – Sep 22 35–50
Squash (Summer) May 5 Jun 30 Jul 7 Aug 25 – Oct 27 45–65
Squash (Winter) May 5 Jun 30 Jul 7 Sep 29 – Nov 24 80–120
Sunchoke Jun 30 Oct 20 – Nov 24 110–150
Sunflower Apr 14 Jun 30 Jul 7 Sep 15 – Nov 3 70–100
Sweet Corn Jun 30 Sep 1 – Oct 13 60–90
Tatsoi May 5 Jun 9 Jun 16 Jul 21 – Aug 25 35–50
Tomatillo Apr 14 Jun 30 Jul 7 Sep 8 – Nov 17 60–85
Tomatoes Apr 14 Jun 30 Jul 7 Sep 8 – Nov 17 60–85
Turnip Jun 9 Jul 21 – Aug 25 40–60
Watercress May 5 Jun 9 Jun 16 Jul 28 – Sep 1 40–60
Watermelon May 5 Jun 30 Jul 7 Sep 15 – Nov 3 70–100
Wax Beans Jun 30 Aug 25 – Oct 20 50–65
Zucchini May 5 Jun 30 Jul 7 Aug 25 – Oct 20 45–60

🍓 Fruits to Grow in Pitkin County

22 fruits that grow well in Zone 4a with planting dates for Pitkin County.

Show all 22 fruits with planting dates
Plant Start Indoors Direct Sow Transplant Harvest Days to Maturity
Alpine Strawberries Jul 14 Oct 13 – Dec 8 90–180
Aronia Jul 14 730–1095
Blueberries Jul 14 730–1095
Cantaloupe Jul 14 Sep 22 – Oct 27 70–90
Cranberries Jul 14 730–1095
Currants Jul 14 730–1095
Elderberries Jul 14 730–1095
Goji Berries Jul 14 730–1095
Gooseberries Jul 14 730–1095
Grapes Jul 14 730–1095
Ground Cherry Jul 14 Sep 22 – Nov 17 65–80
Hardy Kiwi Jul 14 1095–1825
Haskaps Jul 14 730–1095
Honeydew Jul 14 Oct 6 – Nov 17 80–110
Jostaberry Jul 14 730–1095
Lingonberries Jul 14 730–1095
Medlar Jul 14 1095–1825
Mulberries Jul 14 730–1825
Persimmon Jul 14 1095–2555
Raspberries Jul 14 365–730
Serviceberries Jul 14 730–1095
Strawberries Jul 14 Oct 13 – Dec 8 90–365

🌿 Herbs to Grow in Pitkin County

32 herbs that grow well in Zone 4a with planting dates for Pitkin County.

Show all 32 herbs with planting dates
Plant Start Indoors Direct Sow Transplant Harvest Days to Maturity
Angelica May 5 Jun 9 Jun 9 365–730
Anise May 5 Jun 9 Jun 9 Sep 8 – Nov 3 90–120
Basil Apr 21 Jun 23 Jul 7 Sep 1 – Nov 3 50–75
Bee Balm Jun 23 Sep 22 – Nov 17 90–120
Borage May 5 Jun 9 Jun 9 Aug 4 – Sep 22 50–60
Caraway May 5 Jun 9 Jun 9 365–450
Catnip Jun 23 Aug 25 – Oct 27 60–80
Chamomile May 5 Jun 9 Jun 9 Aug 11 – Oct 20 60–90
Chervil May 5 Jun 9 Jun 9 Jul 21 – Sep 22 40–60
Chives Jun 23 Aug 25 – Nov 3 60–90
Cilantro May 5 Jun 9 Jun 9 Jul 21 – Sep 22 40–60
Comfrey Jun 23 Aug 25 – Nov 3 60–90
Dill May 5 Jun 9 Jun 9 Jul 21 – Sep 22 40–60
Echinacea Jun 23 Oct 27 – Nov 17 120–180
Fennel (herb) May 5 Jun 9 Jun 9 Aug 11 – Oct 20 60–90
Garlic Chives Jun 23 Aug 25 – Nov 3 60–90
Horehound Jun 23 Sep 8 – Nov 3 75–90
Hyssop Jun 23 Sep 1 – Nov 3 70–90
Lemon Balm Jun 23 Aug 25 – Oct 13 60–70
Lovage Jun 23 Sep 1 – Nov 3 70–90
Mint Jun 23 Aug 25 – Nov 3 60–90
Oregano Jun 23 Aug 25 – Nov 3 60–90
Parsley May 5 Jun 9 Jun 9 Aug 11 – Oct 13 60–80
Rue Jun 23 Sep 1 – Nov 3 70–90
Sage Jun 23 Sep 8 – Nov 3 75–90
Savory Jun 23 Aug 18 – Oct 13 50–70
Sorrel May 5 Jun 9 Jun 9 Jul 21 – Sep 22 40–60
Tarragon Jun 23 Aug 25 – Nov 3 60–90
Thai Basil Apr 21 Jun 23 Jul 7 Sep 1 – Nov 3 50–75
Thyme Jun 23 Sep 1 – Nov 3 70–90
Valerian Jun 23 Oct 27 – Nov 17 120–180
Yarrow Jun 23 Sep 22 – Nov 17 90–120

Monthly Planting Guide for Pitkin County

Gardening Guides & Resources

Helpful guides from The Ultimate Homestead to improve your garden in Pitkin County.

Frequently Asked Questions

What planting zone is Pitkin County, CO?

Pitkin County is in USDA Hardiness Zone 4a. 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 Pitkin County, CO?

Based on 31 years of NOAA weather station data, the median last spring frost in Pitkin County falls around June 16. In 8 out of 10 years, last frost lands between May 11 and June 27 — a 47-day window of variability. Use June 27 as your conservative safe-to-plant date for frost-sensitive crops.

When is the first fall frost in Pitkin County, CO?

The median first fall frost in Pitkin County arrives around September 7. In cold years it can arrive as early as August 14; in mild years as late as October 7. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.

How long is the growing season in Pitkin County?

Pitkin County has a frost-free growing season of approximately 83 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 1.74 days per decade.

What is the soil like in Pitkin County for gardening?

Pitkin County has predominantly Loam soil with a pH range of 6.6–8.3 and Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.

What is grown commercially in Pitkin County?

Pitkin County has commercial agriculture that includes Cattle, Hay, Wheat, Sugar Beets, Barley. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.

Is Pitkin County a good location for home gardening?

Pitkin County scores 36/100 (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 Pitkin County gardeners in Zone 4a 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.

Level Up Your Garden

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA GHCN-D daily station data (1994–2024) from 3 weather stations in or near Pitkin County (31 years of records). Frost dates represent 50% probability averages; local conditions vary by elevation and microclimate. Last updated: April 2026.