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Carbon County, WY — Planting Guide

Carbon County, Wyoming Zone 5a June

Your June game plan for Carbon County, Wyoming

Each item below is timed to Carbon County, Wyoming's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 31
Avg. first frost September 18
Soil temp (4") 40°F
Watering Critical
Pest pressure High
Daylight 15 hrs
  1. Move basil, cucumber, and peppers into the garden

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

  2. Direct-sow basil, cucumber, and green beans

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

  3. Begin indoor sowing: anemones, cosmos, and dahlias

    Label every cell. You will absolutely forget which is which otherwise.

  4. Basket week: radish, cress, and microgreens

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Get ahead of July
  • Starting indoors: basil, cucumber, and kale
  • First harvests: carrots, kale, and lettuce
  • Fall sowing: carrots, kale, and lettuce

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Carbon County is in USDA Zone 5a. The average last spring frost is May 31 and the first fall frost is September 18, giving you a growing season of approximately 110 days.

At an elevation of 8,469 ft, Carbon County receives approximately 15.2 in of rainfall annually. Summer highs average 80°F with winter lows around 6°F. The predominant soil type is Loam.

Based on 30 years of NOAA climate station data, the last frost date here varies by 24 days year to year — ranging from May 19 in warm years to June 12 in cold years. The growing season is trending longer by about 3.22 days per decade. Carbon County scores 27/100 (Challenging) on the Microclimate Index.

🌡️ Zone

5a (-20°F to -15°F min)

❄️ Last Frost

May 31

🍂 First Frost

September 18

📅 Growing Season

110 days

⛰️ Elevation

8,469 ft

🌧️ Annual Rainfall

15.2 in

Carbon County, WY Short season
110 days
Last Spring Frost May 31
110 growing days
First Fall Frost September 18

Monthly Watering Calendar for Carbon County

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

Why it matters: Most vegetables want about 1 inch of water per week. Carbon County gets 15" a year — months that hit that 1"/week need zero supplemental watering; months that fall short, the table tells you how much to add. Saves you from drowning roots and from drought-stressing plants into bolting.

1"/wk 0" 1.3" 2.5" 3.8" 5" Jan 1.2" Feb 1" Mar 1.5" +2.8" Apr 1.5" +2.3" May 2" +3.2" Jun 1.1" +3" Jul 1.3" +2.8" Aug 1.5" +3.2" Sep 1.1" +3.1" Oct 1.2" Nov 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 1.2 in 7 days None
Feb 1 in 6 days None
Mar 1.5 in 8 days None
Apr 1.5 in 6 days 2.8 in High
May 2 in 8 days 2.3 in High
Jun 1.1 in 4 days 3.2 in Critical
Jul 1.3 in 5 days 3 in High
Aug 1.5 in 6 days 2.8 in High
Sep 1.1 in 5 days 3.2 in Critical
Oct 1.2 in 6 days 3.1 in Critical
Nov 1 in 6 days None
Dec 0.9 in 6 days None

Annual total: 15.3 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.

Carbon County Soil Profile

Soil Type

Loam

Soil pH

6.7-8.3

Drainage

Well Drained

Frost Risk Probability

Based on 30 years of NOAA weather station data from 3 stations

Too early frost risk Safe to Plant May 31 → Sep 18 110 frost-free days Protect crops frost returns May Jun Jul Aug Sep Oct Safe: Jun 12 Protect by: Sep 30

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 12 Sep 30 110 days
Cautious Jun 7 Sep 20 105 days
Average year May 31 Sep 18 110 days
Optimistic May 26 Sep 9 106 days
Aggressive (risky) May 19 Aug 30 103 days
📊
How predictable are frost dates here?

Not very — frost dates can vary by ±24 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 longer here (about 3.2 days per decade). Spring is arriving earlier than it used to. Good news for gardeners.

Gardening Difficulty Score

27 Challenging
Frost Timing Risk
9.2/10
Drought Risk
7.5/10
Soil Difficulty
1.0/10
Altitude Challenge
10.0/10
Climate Shift
10.0/10
Rainfall Challenge
5.9/10

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

Zone 5a Frost Countdown
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Loading...
Last Frost: May 31 First Frost: Sep 18

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

County Extension Office

Carbon County University of Wyoming Extension Extension Office

Phone: 307-766-5124

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 WY →

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 Carbon County

Soil testing High-altitude gardening Pest identification
Finding local nurseries & garden centers in Carbon County

Why Buy Local

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

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

Why this matters: The longest day at Carbon County's latitude gets longer the further north you go. Strawberries, garlic, onions all care. The shortest day gets shorter — which limits winter growing for greens without artificial light.

Longest Day

15 hours

Summer solstice daylight

Shortest Day

9 hours

Winter solstice daylight

Peak Sun Hours

11.2 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 3h 6h 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 9.3 hr 5.2 hr Short day
February 10.4 hr 6.2 hr Short day
March 11.7 hr 7.2 hr Short day
April 13.1 hr 7.9 hr Neutral
May 14.4 hr 9.3 hr Long day
June 15 hr 11.2 hr Long day
July 14.7 hr 10.1 hr Long day
August 13.7 hr 8.9 hr Neutral
September 12.3 hr 8.9 hr Neutral
October 10.8 hr 7.3 hr Short day
November 9.6 hr 5.7 hr Short day
December 9 hr 4.8 hr Short day

Peak sun hours factor in typical cloud cover — use these for solar panel and shade-planning calculations.

Soil Temperature & Composting in Carbon County

Monthly soil temps tell you when to plant warm-season crops, and when your compost pile is actively working.

Why this matters: Compost piles need 130-160°F internal temp to actively break down. Below 50°F ambient, microbial activity slows dramatically. Carbon County's soil temperature curve also tells you when your compost is working and when it's napping.

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.

15° 30° 45° 60° 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 -10°F -1°F ❄️ Dormant ~36 weeks
Feb -8°F -2°F ❄️ Dormant ~36 weeks
Mar 2°F 4°F ❄️ Dormant ~36 weeks
Apr 15°F 12°F ❄️ Dormant ~36 weeks
May 30°F 26°F ❄️ Dormant ~36 weeks
Jun 40°F 33°F ❄️ Dormant ~36 weeks
Jul 47°F 40°F 🐢 Slow ~24 weeks
Aug 47°F 42°F 🐢 Slow ~24 weeks
Sep 38°F 38°F ❄️ Dormant ~36 weeks
Oct 25°F 30°F ❄️ Dormant ~36 weeks
Nov 11°F 19°F ❄️ Dormant ~36 weeks
Dec -3°F 4°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 Carbon County

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

For new gardeners: Warm humid regions cycle through pest generations 3-5x faster than cold dry regions. Carbon County's pest score is your early-warning system: high score means commit to disease-resistant varieties and accept some crop loss to bugs.

Insect Pest Pressure

4.8 / 10

Moderate — common pests appear but manageable with monitoring.

Disease Risk

2.3 / 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 Moderate Jun, Jul, Aug
Colorado potato beetle Moderate Jun, Jul
Flea beetles Moderate 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 Carbon County

Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with planting dates calibrated for your area.

Quick context: You don't need a farm to use cover crops. A 4x8 raised bed accepts cover crops just as well as a half-acre. Carbon County's climate determines the calendar; the principle is universal.

Spring Cover Crops (2 options) — Build soil before the main growing season
Crop Plant By Terminate N-Fixing Soil Benefit
Buckwheat Jun 5 Jul 24 Rapid growth, attracts pollinators, suppresses weeds
White clover Apr 30 Jul 24 ✓ 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 11 Aug 28 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 10 May 17 Deep taproot breaks compaction, excellent for clay soils
Hairy vetch Jul 6 May 10 ✓ Yes Excellent nitrogen fixer, good for depleted soils
Oats Aug 14 May 10 Quick biomass, winterkills in cold zones — no spring tillage needed
Winter rye Jun 22 May 17 Suppresses weeds, prevents erosion, breaks up compacted soil
Winter wheat Jun 9 May 10 Erosion control, weed suppression, good biomass

Wind & Microclimate in Carbon County

What this means for you: Light wind is good (strengthens stems, aids pollination); strong wind is bad (snaps stems, dries leaves, scatters seeds). Carbon County averages 11.6 mph. If you garden near coast, ridge, or open plains, you're likely above that — plan for it.

Wind dries soil, stresses plants, and affects frost patterns. Understanding your exposure helps with garden placement.

Seasonal Wind Speed

Spring: 16 mph   Summer: 12 mph

Fall: 13 mph   Winter: 16 mph

Prevailing wind: W. Windy area — plant a windbreak hedge on the W side of your garden.

Windbreak Benefit

9.4/10

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 2,724 ft of elevation range — cold air pools in low spots. Avoid planting frost-sensitive crops in valleys.

Rainwater Harvesting in Carbon County

How much water you can collect, when to collect it, and what size system you need for your garden.

Quick context: Rainwater scales linearly with roof area. A 2,000 sq ft roof in Carbon County captures ~1,200 gallons per 1" of rain — given 15" annual rainfall, that's thousands of gallons a year if you have storage to hold it.

Annual Collection

7,625 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

Unrestricted

Rainwater harvesting is fully legal in your state with no restrictions.

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 15.3 inches of rain per year
  • A 1,000 sq ft roof can collect roughly 7,625 gallons annually
  • Rainwater harvesting is fully legal in your state
  • 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 Carbon County

Soil Type

Loam

Soil pH 6.7–8.3 · Well Drained drainage

Native soil is well-suited to most vegetables and herbs with regular compost additions.

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

110-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.

Your Free Printable Garden Planner

Plan every bed, every planting, every harvest — in one place. This 22-page printable includes your zone's planting calendar, a month-by-month task list, a seed inventory tracker, a harvest log, and succession-planting charts. Built to print, write in, and actually use all season.

Instant PDF download. No spam, unsubscribe any time.

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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 Carbon County

105 vegetables that grow well in Zone 5a with planting dates for Carbon County.

Show all 105 vegetables with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Harvest Days to Maturity
Acorn Squash Apr 26 Jun 7 Jun 14 Sep 6 – Oct 11 80–100
Amaranth Apr 5 Jun 7 Jun 14 Sep 13 – Nov 1 90–120
Arugula Apr 26 May 17 May 31 Jul 10 Jul 5 – Sep 6 30–50
Asparagus Jun 14 730–1095
Beets May 17 Jul 10 Jul 12 – Aug 9 50–70
Belgian Endive Apr 26 May 17 May 31 Jul 10 Sep 20 – Nov 15 110–150
Bitter Melon Apr 5 Jun 7 Jun 14 Aug 16 – Sep 27 60–90
Black Beans Jun 7 Sep 6 – Oct 25 90–120
Bok Choy Apr 26 May 17 May 31 Jul 10 Jul 12 – Aug 16 40–60
Broccoli Apr 26 May 17 May 31 Jul 10 Aug 2 – Sep 13 60–90
Broccoli Rabe Apr 26 May 17 May 31 Jul 10 Jul 12 – Aug 16 40–60
Brussels Sprouts Apr 26 May 17 May 31 Jul 10 Aug 30 – Oct 25 90–130
Butternut Squash Apr 26 Jun 7 Jun 14 Sep 13 – Oct 18 85–110
Cabbage Apr 26 May 17 May 31 Jul 10 Aug 2 – Sep 27 60–100
Calabash Apr 5 Jun 7 Jun 14 Sep 6 – Nov 1 80–120
Carrots May 17 Jul 10 Jul 19 – Aug 23 60–80
Cauliflower Apr 26 May 17 May 31 Jul 10 Jul 26 – Sep 27 55–100
Celeriac Apr 26 May 17 May 31 Jul 10 Sep 13 – Oct 18 100–120
Celery Apr 26 May 17 May 31 Jul 10 Aug 23 – Oct 18 80–120
Celtuce Apr 26 May 17 May 31 Jul 10 Aug 2 – Sep 13 60–90
Chard Apr 26 May 17 May 31 Jul 10 Jul 26 – Sep 13 50–60
Chickpeas Apr 26 May 17 May 31 Jul 10 Aug 23 – Oct 4 80–110
Chicory Apr 26 May 17 May 31 Jul 10 Aug 2 – Sep 13 60–85
Chinese Cabbage Apr 26 May 17 May 31 Jul 10 Jul 26 – Aug 23 50–70
Christmas Lima Beans Apr 5 Jun 7 Jun 14 Sep 6 – Oct 11 80–100
Collard Greens Apr 26 May 17 May 31 Jul 10 Jul 26 – Sep 27 55–75
Corn Jun 7 Aug 9 – Oct 4 60–100
Cowpeas Jun 7 Aug 9 – Sep 20 60–90
Cress Apr 26 May 17 May 31 Jul 10 Jun 14 – Jul 5 14–21
Crookneck Squash Apr 26 Jun 7 Jun 14 Aug 2 – Aug 30 45–60
Crosne May 17 Jul 10 Oct 18 – Nov 1 150–200
Cucumber Apr 26 Jun 7 Jun 14 Aug 9 – Oct 4 50–70
Daikon May 17 Jul 10 Jul 12 – Aug 9 50–70
Delicata Squash Apr 26 Jun 7 Jun 14 Sep 6 – Oct 11 80–100
Edamame Jun 7 Aug 23 – Oct 4 75–100
Eggplant Mar 22 Jun 7 Jun 14 Aug 23 – Oct 25 65–85
Endive Apr 26 May 17 May 31 Jul 10 Jul 19 – Aug 23 45–65
Escarole Apr 26 May 17 May 31 Jul 10 Jul 26 – Aug 23 50–70
Fava Beans Apr 26 May 17 May 31 Jul 10 Aug 16 – Sep 27 75–100
Fennel Apr 5 Jun 7 Jun 14 Aug 16 – Sep 27 60–90
Garlic Aug 7 Nov 6 – Jan 22 90–240
Green Beans Jun 7 Aug 2 – Sep 27 50–65
Horseradish Jun 14 Oct 18 – Nov 29 120–180
Hot Peppers Mar 22 Jun 7 Jun 14 Aug 23 – Nov 29 70–120
Hubbard Squash Apr 26 Jun 7 Jun 14 Sep 27 – Nov 1 100–120
Kabocha Apr 26 Jun 7 Jun 14 Sep 13 – Oct 11 85–100
Kai Lan Apr 26 May 17 May 31 Jul 10 Jul 19 – Aug 16 45–60
Kale Apr 26 May 17 May 31 Jul 10 Jul 26 – Sep 20 50–70
Kidney Beans Jun 7 Sep 6 – Oct 11 85–110
Kohlrabi Apr 26 May 17 May 31 Jul 10 Jul 19 – Aug 23 45–65
Komatsuna Apr 26 May 17 May 31 Jul 10 Jul 5 – Aug 9 35–50
Leeks Apr 26 May 17 May 31 Jul 10 Aug 30 – Nov 15 90–150
Lentils Apr 26 May 17 May 31 Jul 10 Aug 23 – Oct 4 80–110
Lettuce Apr 26 May 17 May 31 Jul 10 Jul 5 – Sep 13 30–60
Lima Beans Jun 7 Aug 9 – Sep 20 60–90
Mache Apr 26 May 17 May 31 Jul 10 Jul 12 – Aug 16 40–60
Melon Apr 26 Jun 7 Jun 14 Aug 23 – Oct 11 70–100
Microgreens Apr 26 May 17 May 31 Jul 10 Jun 7 – Jul 5 7–21
Mitsuba Apr 26 May 17 May 24 Jul 10 Jul 19 – Sep 13 50–70
Mizuna Apr 26 May 17 May 31 Jul 10 Jul 5 – Aug 2 30–45
Mustard Greens Apr 26 May 17 May 31 Jul 10 Jul 5 – Sep 6 30–50
Napa Cabbage Apr 26 May 17 May 31 Jul 10 Jul 26 – Aug 30 55–75
New Zealand Spinach Apr 5 Jun 7 Jun 14 Aug 9 – Sep 6 55–70
Okra Apr 5 Jun 7 Jun 14 Aug 9 – Oct 4 50–65
Onion Apr 26 May 17 May 31 Jul 10 Aug 30 – Oct 18 90–120
Pac Choi Apr 26 May 17 May 31 Jul 10 Jul 12 – Aug 9 40–55
Parsnip May 17 Jul 10 Aug 30 – Oct 11 100–130
Patty Pan Squash Apr 26 Jun 7 Jun 14 Aug 2 – Aug 30 45–60
Peas Apr 26 May 17 May 31 Jul 10 Jul 26 – Sep 20 55–70
Peppers Mar 22 Jun 7 Jun 14 Aug 16 – Oct 25 60–90
Pole Beans Apr 5 Jun 7 Jun 14 Aug 9 – Oct 4 55–70
Potatoes Apr 5 Jun 7 Jun 14 Aug 23 – Nov 1 70–120
Pumpkin Apr 26 Jun 7 Jun 14 Sep 13 – Nov 1 85–120
Purslane Apr 26 May 17 May 31 Jul 10 Jul 12 – Aug 16 40–60
Radicchio Apr 26 May 17 May 31 Jul 10 Aug 2 – Sep 6 60–80
Radish May 17 Jul 10 Jun 14 – Jul 5 22–35
Rhubarb Jun 21 365–730
Romanesco Apr 26 May 17 May 31 Jul 10 Aug 16 – Sep 27 75–100
Rutabaga May 17 Jul 10 Aug 9 – Sep 13 80–100
Salsify May 17 Jul 10 Aug 30 – Oct 11 100–130
Savoy Cabbage Apr 26 May 17 May 31 Jul 10 Aug 9 – Oct 4 70–110
Scallions Apr 26 May 17 May 31 Jul 10 Jul 26 – Aug 23 50–70
Scarlet Runner Beans Apr 5 Jun 7 Jun 14 Aug 16 – Sep 20 60–80
Shallot Apr 26 May 17 May 31 Jul 10 Aug 30 – Oct 18 90–120
Shiso Apr 12 Jun 7 Jun 14 Aug 9 – Oct 4 50–70
Snap Peas Apr 5 Jun 7 Jun 14 Aug 9 – Oct 4 55–70
Snow Peas Apr 26 May 17 May 31 Jul 10 Jul 26 – Sep 20 50–65
Soybeans Jun 7 Aug 30 – Oct 25 80–120
Spaghetti Squash Apr 26 Jun 7 Jun 14 Sep 13 – Oct 11 85–100
Spinach Apr 26 May 17 May 31 Jul 10 Jul 5 – Sep 6 35–50
Squash (Summer) Apr 26 Jun 7 Jun 14 Aug 2 – Oct 4 45–65
Squash (Winter) Apr 26 Jun 7 Jun 14 Sep 6 – Nov 1 80–120
Sunchoke Jun 14 Oct 4 – Nov 29 110–150
Sweet Corn Jun 7 Aug 9 – Sep 20 60–90
Sweet Potatoes Apr 5 Jun 7 Jun 14 Sep 13 – Nov 1 90–120
Tatsoi Apr 26 May 17 May 31 Jul 10 Jul 5 – Aug 9 35–50
Tomatillo Apr 5 Jun 7 Jun 14 Aug 16 – Oct 25 60–85
Tomatoes Apr 5 Jun 7 Jun 14 Aug 16 – Oct 25 60–85
Turnip May 17 Jul 10 Jun 28 – Aug 2 40–60
Watercress Apr 26 May 17 May 31 Jul 10 Jul 12 – Aug 16 40–60
Watermelon Apr 26 Jun 7 Jun 14 Aug 23 – Oct 11 70–100
Wax Beans Jun 7 Aug 2 – Sep 27 50–65
Winter Melon Apr 5 Jun 7 Jun 14 Sep 13 – Nov 1 90–120
Yard Long Beans Apr 5 Jun 7 Jun 14 Aug 9 – Sep 20 55–80
Zucchini Apr 26 Jun 7 Jun 14 Aug 2 – Sep 27 45–60

🍓 Fruits to Grow in Carbon County

27 fruits that grow well in Zone 5a with planting dates for Carbon County.

Show all 27 fruits with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Harvest Days to Maturity
Alpine Strawberries Jun 21 Sep 20 – Dec 6 90–180
Aronia Jun 21 730–1095
Blackberries Jun 21 365–730
Blueberries Jun 21 730–1095
Boysenberries Jun 21 365–730
Cantaloupe Jun 21 Aug 30 – Oct 4 70–90
Che Fruit Jun 21 1095–1825
Cranberries Jun 21 730–1095
Currants Jun 21 730–1095
Elderberries Jun 21 730–1095
Goji Berries Jun 21 730–1095
Gooseberries Jun 21 730–1095
Grapes Jun 21 730–1095
Ground Cherry Jun 21 Aug 30 – Oct 25 65–80
Hardy Kiwi Jun 21 1095–1825
Haskaps Jun 21 730–1095
Honeydew Jun 21 Sep 13 – Oct 25 80–110
Jostaberry Jun 21 730–1095
Lingonberries Jun 21 730–1095
Medlar Jun 21 1095–1825
Mulberries Jun 21 730–1825
Pawpaw Jun 21 1095–2555
Persimmon Jun 21 1095–2555
Quince Jun 21 1095–1825
Raspberries Jun 21 365–730
Serviceberries Jun 21 730–1095
Strawberries Jun 21 Sep 20 – Dec 6 90–365

🌿 Herbs to Grow in Carbon County

34 herbs that grow well in Zone 5a with planting dates for Carbon County.

Show all 34 herbs with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Harvest Days to Maturity
Angelica Apr 26 May 17 May 24 Jul 10 365–730
Anise Apr 26 May 17 May 24 Jul 10 Aug 23 – Nov 8 90–120
Basil Apr 12 Jun 7 Jun 14 Aug 9 – Oct 11 50–75
Bee Balm Jun 7 Sep 6 – Nov 22 90–120
Borage Apr 26 May 17 May 24 Jul 10 Jul 19 – Sep 6 50–60
Caraway Apr 26 May 17 May 24 Jul 10 365–450
Catnip Jun 7 Aug 9 – Oct 11 60–80
Chamomile Apr 26 May 17 May 24 Jul 10 Jul 26 – Oct 4 60–90
Chervil Apr 26 May 17 May 24 Jul 10 Jul 5 – Sep 6 40–60
Chives Jun 7 Aug 9 – Oct 18 60–90
Cilantro Apr 26 May 17 May 24 Jul 10 Jul 5 – Sep 6 40–60
Comfrey Jun 7 Aug 9 – Oct 18 60–90
Cumin Apr 26 May 17 May 24 Jul 10 Sep 6 – Nov 8 100–120
Dill Apr 26 May 17 May 24 Jul 10 Jul 5 – Sep 6 40–60
Epazote Apr 12 Jun 7 Jun 14 Aug 2 – Sep 27 45–60
Fennel (herb) Apr 26 May 17 May 24 Jul 10 Jul 26 – Oct 4 60–90
Feverfew Jun 7 Sep 6 – Nov 22 90–120
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
Lemon Thyme Jun 7 Aug 16 – Oct 18 70–90
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 26 May 17 May 24 Jul 10 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 26 May 17 May 24 Jul 10 Jul 5 – Sep 6 40–60
Tarragon Jun 7 Aug 9 – Oct 18 60–90
Thai Basil Apr 12 Jun 7 Jun 14 Aug 9 – Oct 11 50–75
Thyme Jun 7 Aug 16 – Oct 18 70–90
Valerian Jun 7 Oct 11 – Nov 22 120–180

🌸 Flowers to Grow in Carbon County

51 flowers that grow well in Zone 5a with planting dates for Carbon County.

Show all 51 flowers with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Bloom Days to Maturity
Ageratum Apr 12 Jun 7 Jun 7 Aug 2 – Oct 25 60–75
Alliums Aug 7 Sep 11 – Oct 9 28–42
Anemones May 3 May 31 Jul 12 – Aug 9 90–120
Astilbe Mar 29 Jun 14 Aug 30 – Nov 1 70–100
Bachelor's Button Apr 19 May 10 May 31 Aug 2 – Oct 11 60–90
Begonias Mar 22 Jun 7 Aug 16 – Nov 8 70–90
Black-eyed Susan Mar 29 May 31 Jun 14 Aug 30 – Nov 29 60–80
Bleeding Hearts Mar 29 Jun 14 Aug 9 – Sep 20 60–90
Calendula Apr 19 May 10 May 31 Jul 19 – Oct 11 50–70
Celosia Apr 26 Jun 14 Jun 14 Aug 16 – Nov 15 60–90
Columbine Mar 29 Jun 14 Jun 14 Aug 9 – Sep 20 70–100
Coreopsis Mar 29 Jun 7 Jun 14 Aug 23 – Nov 29 60–80
Cosmos May 3 Jun 7 Jun 7 Aug 16 – Nov 8 60–90
Crocus Aug 7 Jun 19 – Jul 10 10–20
Daffodils Aug 7 Jun 26 – Jul 17 20–40
Dahlias May 3 Jun 7 Jun 7 Aug 30 – Nov 22 70–120
Daylily Mar 29 Jun 14 Sep 6 – Nov 29 60–90
Dianthus Mar 29 May 3 May 17 Jul 5 – Sep 20 60–80
Echinacea (Purple Coneflower) Mar 29 Jun 14 Jun 14 Sep 6 – Nov 29 70–90
Foxglove Mar 29 Jun 14 Jun 14 Aug 9 – Sep 20 80–120
Gaillardia (Blanket Flower) Apr 5 Jun 14 Jun 14 Aug 23 – Dec 13 70–100
Geraniums Mar 22 Jun 7 Aug 16 – Nov 8 70–100
Gladiolus Jun 7 Jun 7 Aug 30 – Nov 22 70–100
Hostas Mar 22 Jun 14 Sep 6 – Nov 29 60–90
Hyacinths Aug 7 Jul 17 – Aug 14 14–28
Hydrangeas Mar 22 Jun 14 Aug 30 – Nov 15 90–150
Impatiens Apr 5 Jun 7 Aug 16 – Nov 8 60–75
Irises Division Jun 14 Aug 9 – Sep 13 60–100
Larkspur May 3 Jul 12 – Sep 6 60–90
Lavender Mar 22 Jun 21 Aug 30 – Oct 11 90–120
Lilies Division Jun 14 Aug 23 – Nov 15 70–120
Lobelia Mar 22 May 24 Jul 19 – Sep 27 70–80
Lupine Mar 29 Jun 14 Jun 14 Aug 9 – Sep 20 75–100
Marigolds Apr 19 Jun 7 Jun 7 Aug 2 – Oct 25 50–70
Nasturtium May 3 Jun 7 Jun 7 Aug 2 – Nov 8 55–65
Pansy Mar 22 May 31 Jul 26 – Sep 20 70–90
Peonies Division Jun 14 Aug 23 – Oct 4 90–120
Petunia Apr 5 Jun 7 Aug 16 – Nov 8 70–90
Phlox Mar 29 Jun 14 Jun 14 Aug 30 – Nov 15 80–110
Portulaca Apr 26 Jun 14 Jun 14 Aug 2 – Nov 1 50–70
Roses Mar 22 Jun 14 Aug 30 – Nov 29 90–180
Salvia Mar 29 Jun 7 Aug 16 – Nov 8 70–90
Sedum (Stonecrop) Mar 29 Jun 14 Oct 11 – Dec 13 60–90
Snapdragon Mar 22 May 17 May 31 Aug 9 – Oct 11 70–100
Sunflower May 10 Jun 7 Jun 7 Aug 30 – Nov 8 70–100
Sweet Alyssum Apr 12 May 17 May 31 Jul 12 – Sep 20 45–60
Sweet Pea Apr 19 Apr 26 May 31 Aug 16 – Oct 18 65–85
Tulips Aug 7 Jul 10 – Jul 31 15–30
Vinca (Annual) Mar 15 Jun 14 Aug 23 – Nov 8 70–90
Yarrow Mar 29 May 31 Jun 14 Aug 23 – Nov 29 60–90
Zinnia May 3 Jun 7 Jun 7 Aug 16 – Nov 8 60–70
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Monthly Planting Guide for Carbon County

Gardening Guides & Resources

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

Frequently Asked Questions

What planting zone is Carbon County, WY?

Carbon 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 Carbon County, WY?

Based on 30 years of NOAA weather station data, the median last spring frost in Carbon County falls around May 31. In 8 out of 10 years, last frost lands between May 19 and June 12 — a 24-day window of variability. Use June 12 as your conservative safe-to-plant date for frost-sensitive crops.

When is the first fall frost in Carbon County, WY?

The median first fall frost in Carbon County arrives around September 18. In cold years it can arrive as early as August 30; 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 Carbon County?

Carbon County has a frost-free growing season of approximately 110 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 3.22 days per decade.

What is the soil like in Carbon County for gardening?

Carbon County has predominantly Loam soil with a pH range of 6.7–8.3 and Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.

What is grown commercially in Carbon County?

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

Is Carbon County a good location for home gardening?

Carbon County scores 27/100 (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.

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A 22-page printable planner built for Carbon County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Composting Guide for Homesteaders

Composting Guide for Homesteaders

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Turn kitchen scraps and yard waste into compost that actually feeds the garden — instead of a pile that smells, attracts pests, and never breaks down.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA GHCN-D daily station data (1994–2024) from 3 weather stations in or near Carbon County (30 years of records). Frost dates represent 50% probability averages; local conditions vary by elevation and microclimate. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.