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Carbon County, UT — Planting Guide

Carbon County, Utah Zone 6a June

Your June planting checklist for Carbon County, Utah

Your garden in Carbon County, Utah is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost May 17
Avg. first frost September 27
Soil temp (4") 54°F
Watering Critical
Pest pressure High
Daylight 14.8 hrs
  1. Harden off and plant alpine strawberries, aronia, and blackberries

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Start cucumber, kale, and lettuce indoors

    You're about 15 weeks out from your last frost — the perfect window to get these germinating indoors.

  3. Start harvesting lettuce, radish, and anemones

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

July will be here before you know it — start on
  • Starting indoors: basil, peppers, and pole beans
  • First harvests: basil, carrots, and cucumber
  • Fall sowing: carrots, kale, and lettuce

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Carbon County is in USDA Zone 6a. The average last spring frost is May 17 and the first fall frost is September 27, giving you a growing season of approximately 133 days.

At an elevation of 5,755 ft, Carbon County receives approximately 14.2 in of rainfall annually. Summer highs average 84°F with winter lows around 14°F. The predominant soil type is Loam.

Based on 31 years of NOAA climate station data, the last frost date here varies by 40 days year to year — ranging from April 29 in warm years to June 8 in cold years. The growing season is trending shorter by about 0.57 days per decade. Carbon County scores 39/100 (Challenging) on the Microclimate Index.

🌡️ Zone

6a (-10°F to -5°F min)

❄️ Last Frost

May 17

🍂 First Frost

September 27

📅 Growing Season

133 days

⛰️ Elevation

5,755 ft

🌧️ Annual Rainfall

14.2 in

Carbon County, UT Short season
133 days
Last Spring Frost May 17
133 growing days
First Fall Frost September 27

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 14" 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" Feb 0.9" Mar 1.2" +2.8" Apr 1.5" +2.5" May 1.8" +3.2" Jun 1.1" +3" Jul 1.3" +3" Aug 1.3" +3.2" Sep 1.1" +3" Oct 1.3" Nov 0.9" Dec 0.8"
Rainfall sufficient Supplemental water needed Heavy watering required - - - 1"/week garden need
View detailed monthly data
MonthAvg RainfallRainy DaysExtra Water NeededWatering Effort
Jan 1 in 7 days None
Feb 0.9 in 6 days None
Mar 1.2 in 7 days None
Apr 1.5 in 6 days 2.8 in High
May 1.8 in 6 days 2.5 in High
Jun 1.1 in 4 days 3.2 in Critical
Jul 1.3 in 5 days 3 in High
Aug 1.3 in 7 days 3 in High
Sep 1.1 in 6 days 3.2 in Critical
Oct 1.3 in 6 days 3 in High
Nov 0.9 in 6 days None
Dec 0.8 in 7 days None

Annual total: 14.2 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

6.4-8.3

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 May 17 → Sep 27 133 frost-free days Protect crops frost returns Apr May Jun Jul Aug Sep Oct Nov Safe: Jun 8 Protect by: Oct 12

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 8 Oct 12 126 days
Cautious May 26 Oct 5 132 days
Average year May 17 Sep 27 133 days
Optimistic May 7 Sep 21 137 days
Aggressive (risky) Apr 29 Sep 13 137 days
📊
How predictable are frost dates here?

Not very — frost dates can vary by ±40 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?

Slightly — seasons are trending a bit shorter (0.6 days/decade). Stay conservative with planting dates.

Gardening Difficulty Score

39 Challenging
Frost Timing Risk
10.0/10
Drought Risk
7.5/10
Soil Difficulty
1.0/10
Altitude Challenge
9.5/10
Climate Shift
2.3/10
Rainfall Challenge
6.3/10

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

Zone 6a Frost Countdown
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Loading...
Last Frost: May 17 First Frost: Sep 27

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 Utah State University Extension Extension Office

Phone: 435-797-2200

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 UT →

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 Arid 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 UT" 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 UT" or check your extension office and local parks department. Facebook groups like "Carbon County Gardeners" or "Utah 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.

Show 6 more succession options
After Hyacinths (harvest ends May 24) 126 days until frost
After Patty Pan Squash (harvest ends Aug 16) 42 days until frost
After Alliums (harvest ends Jul 12) 77 days until frost
After Ranunculus (harvest ends Jul 26) 63 days until frost
After Cilantro (harvest ends Aug 23) 35 days until frost
After Arugula (harvest ends Aug 23) 35 days until frost

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

14.8 hours

Summer solstice daylight

Shortest Day

9.2 hours

Winter solstice daylight

Peak Sun Hours

10.2 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 9.5 hr 5.2 hr Short day
February 10.5 hr 6.3 hr Short day
March 11.7 hr 7.2 hr Short day
April 13.1 hr 7.9 hr Neutral
May 14.2 hr 8.7 hr Long day
June 14.8 hr 10.2 hr Long day
July 14.5 hr 10.2 hr Long day
August 13.6 hr 8.8 hr Neutral
September 12.2 hr 8.7 hr Neutral
October 10.9 hr 6.7 hr Short day
November 9.8 hr 5.8 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 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 warm enough from Jul through Aug.

Best Month to Compost

Jun

Microbial activity peaks when soil is warm.

Active Composting

4 months

Short season — insulate pile or use indoor vermicomposting.

60°F 70°F 20° 40° 60° 80° 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 6°F 16°F ❄️ Dormant ~36 weeks
Feb 8°F 15°F ❄️ Dormant ~36 weeks
Mar 15°F 17°F ❄️ Dormant ~36 weeks
Apr 29°F 27°F ❄️ Dormant ~36 weeks
May 43°F 37°F 🐢 Slow ~24 weeks
Jun 54°F 47°F ♻️ Active ~14 weeks
Jul 61°F 54°F ♻️ Active ~14 weeks
Aug 60°F 58°F ♻️ Active ~14 weeks
Sep 54°F 54°F ♻️ Active ~14 weeks
Oct 41°F 45°F 🐢 Slow ~24 weeks
Nov 25°F 33°F ❄️ Dormant ~36 weeks
Dec 13°F 22°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

4.7 / 10

Moderate — common pests appear but manageable with monitoring.

Disease Risk

1.4 / 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
Japanese beetles Moderate Jun, Jul, Aug
Squash bugs Low Jun, Jul, Aug
Tomato hornworms Low Jul, Aug
Cabbage loopers Moderate 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 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 (3 options) — Build soil before the main growing season
Crop Plant By Terminate N-Fixing Soil Benefit
Buckwheat May 18 Jul 19 Rapid growth, attracts pollinators, suppresses weeds
Sorghum-sudan grass May 24 Jul 19 Massive biomass, breaks compaction, suppresses nematodes
White clover Apr 19 Jul 26 ✓ 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 6 Aug 30 Deep roots break compaction, attract pollinators and beneficial insects
Fall Cover Crops (6 options) — Plant after harvest to protect soil over winter
Crop Plant By Terminate N-Fixing Soil Benefit
Austrian winter peas Aug 3 Apr 26 ✓ Yes Fixes nitrogen, good for heavy clay soils
Daikon radish Aug 6 May 3 Deep taproot breaks compaction, excellent for clay soils
Hairy vetch Jul 7 Apr 26 ✓ Yes Excellent nitrogen fixer, good for depleted soils
Oats Aug 14 Apr 26 Quick biomass, winterkills in cold zones — no spring tillage needed
Winter rye Jun 20 May 3 Suppresses weeds, prevents erosion, breaks up compacted soil
Winter wheat Jul 6 May 3 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 11.7 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: 15 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

6.8/10

Moderately beneficial — a simple fence or trellis can protect delicate crops from wind stress.

Frost Pocket Risk

Moderate

Some terrain variation (954 ft range). Garden on slopes or higher ground if possible to avoid late-season frost pockets.

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 14" annual rainfall, that's thousands of gallons a year if you have storage to hold it.

Annual Collection

7,077 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 2,000 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, Jul, Aug

Highest rainfall months — your barrels will fill up quickly during these months.

Months to Draw From Storage

Feb, Nov, 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 14.2 inches of rain per year
  • A 1,000 sq ft roof can collect roughly 7,077 gallons annually
  • Check UT 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 Carbon County

Soil Type

Loam

Soil pH 6.4–8.3 · 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

133-day frost-free season

Start warm-season crops indoors and focus on short-season varieties. Cold frames extend your season by 3–4 weeks in fall.

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.

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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

107 vegetables that grow well in Zone 6a with planting dates for Carbon County.

Show all 107 vegetables with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Harvest Days to Maturity
Acorn Squash Apr 12 May 24 May 31 Aug 23 – Sep 27 80–100
Amaranth Mar 22 May 24 May 31 Aug 30 – Oct 18 90–120
Arugula Apr 12 May 3 May 17 Jul 19 Jun 21 – Aug 23 30–50
Asparagus May 31 730–1095
Beets May 3 Jul 19 Jun 28 – Jul 26 50–70
Belgian Endive Apr 12 May 3 May 17 Jul 19 Sep 6 – Nov 1 110–150
Bitter Melon Mar 22 May 24 May 31 Aug 2 – Sep 13 60–90
Black Beans May 24 Aug 23 – Oct 11 90–120
Bok Choy Apr 12 May 3 May 17 Jul 19 Jun 28 – Aug 2 40–60
Broccoli Apr 12 May 3 May 17 Jul 19 Jul 19 – Aug 30 60–90
Broccoli Rabe Apr 12 May 3 May 17 Jul 19 Jun 28 – Aug 2 40–60
Brussels Sprouts Apr 12 May 3 May 17 Jul 19 Aug 16 – Oct 11 90–130
Butternut Squash Apr 12 May 24 May 31 Aug 30 – Oct 4 85–110
Cabbage Apr 12 May 3 May 17 Jul 19 Jul 19 – Sep 13 60–100
Calabash Mar 22 May 24 May 31 Aug 23 – Oct 18 80–120
Carrots May 3 Jul 19 Jul 5 – Aug 9 60–80
Cauliflower Apr 12 May 3 May 17 Jul 19 Jul 12 – Sep 13 55–100
Celeriac Apr 12 May 3 May 17 Jul 19 Aug 30 – Oct 4 100–120
Celery Apr 12 May 3 May 17 Jul 19 Aug 9 – Oct 4 80–120
Celtuce Apr 12 May 3 May 17 Jul 19 Jul 19 – Aug 30 60–90
Chard Apr 12 May 3 May 17 Jul 19 Jul 12 – Aug 30 50–60
Chickpeas Apr 12 May 3 May 17 Jul 19 Aug 9 – Sep 20 80–110
Chicory Apr 12 May 3 May 17 Jul 19 Jul 19 – Aug 30 60–85
Chinese Cabbage Apr 12 May 3 May 17 Jul 19 Jul 12 – Aug 9 50–70
Christmas Lima Beans Mar 22 May 24 May 31 Aug 23 – Sep 27 80–100
Collard Greens Apr 12 May 3 May 17 Jul 19 Jul 12 – Sep 13 55–75
Corn May 24 Jul 26 – Sep 20 60–100
Cowpeas May 24 Jul 26 – Sep 6 60–90
Cress Apr 12 May 3 May 17 Jul 19 May 31 – Jun 21 14–21
Crookneck Squash Apr 12 May 24 May 31 Jul 19 – Aug 16 45–60
Crosne May 3 Jul 19 Oct 4 – Nov 15 150–200
Cucumber Apr 12 May 24 May 31 Jul 26 – Sep 20 50–70
Daikon May 3 Jul 19 Jun 28 – Jul 26 50–70
Delicata Squash Apr 12 May 24 May 31 Aug 23 – Sep 27 80–100
Edamame May 24 Aug 9 – Sep 20 75–100
Eggplant Mar 8 May 24 May 31 Aug 9 – Oct 11 65–85
Endive Apr 12 May 3 May 17 Jul 19 Jul 5 – Aug 9 45–65
Escarole Apr 12 May 3 May 17 Jul 19 Jul 12 – Aug 9 50–70
Fava Beans Apr 12 May 3 May 17 Jul 19 Aug 2 – Sep 13 75–100
Fennel Mar 22 May 24 May 31 Aug 2 – Sep 13 60–90
Garlic Aug 16 Nov 15 – Feb 28 90–240
Green Beans May 24 Jul 19 – Sep 13 50–65
Horseradish May 31 Oct 4 – Dec 13 120–180
Hot Peppers Mar 8 May 24 May 31 Aug 9 – Nov 15 70–120
Hubbard Squash Apr 12 May 24 May 31 Sep 13 – Oct 18 100–120
Kabocha Apr 12 May 24 May 31 Aug 30 – Sep 27 85–100
Kai Lan Apr 12 May 3 May 17 Jul 19 Jul 5 – Aug 2 45–60
Kale Apr 12 May 3 May 17 Jul 19 Jul 12 – Sep 6 50–70
Kidney Beans May 24 Aug 23 – Sep 27 85–110
Kohlrabi Apr 12 May 3 May 17 Jul 19 Jul 5 – Aug 9 45–65
Komatsuna Apr 12 May 3 May 17 Jul 19 Jun 21 – Jul 26 35–50
Leeks Apr 12 May 3 May 17 Jul 19 Aug 16 – Nov 1 90–150
Lentils Apr 12 May 3 May 17 Jul 19 Aug 9 – Sep 20 80–110
Lettuce Apr 12 May 3 May 17 Jul 19 Jun 21 – Aug 30 30–60
Lima Beans May 24 Jul 26 – Sep 6 60–90
Loofah Mar 22 May 24 May 31 Sep 13 – Nov 15 100–150
Luffa Mar 22 May 24 May 31 Aug 30 – Nov 15 90–150
Mache Apr 12 May 3 May 17 Jul 19 Jun 28 – Aug 2 40–60
Melon Apr 12 May 24 May 31 Aug 9 – Sep 27 70–100
Microgreens Apr 12 May 3 May 17 Jul 19 May 24 – Jun 21 7–21
Mitsuba Apr 12 May 3 May 10 Jul 19 Jul 5 – Aug 30 50–70
Mizuna Apr 12 May 3 May 17 Jul 19 Jun 21 – Jul 19 30–45
Mustard Greens Apr 12 May 3 May 17 Jul 19 Jun 21 – Aug 23 30–50
Napa Cabbage Apr 12 May 3 May 17 Jul 19 Jul 12 – Aug 16 55–75
New Zealand Spinach Mar 22 May 24 May 31 Jul 26 – Aug 23 55–70
Okra Mar 22 May 24 May 31 Jul 26 – Sep 20 50–65
Onion Apr 12 May 3 May 17 Jul 19 Aug 16 – Oct 4 90–120
Pac Choi Apr 12 May 3 May 17 Jul 19 Jun 28 – Jul 26 40–55
Parsnip May 3 Jul 19 Aug 16 – Sep 27 100–130
Patty Pan Squash Apr 12 May 24 May 31 Jul 19 – Aug 16 45–60
Peas Apr 12 May 3 May 17 Jul 19 Jul 12 – Sep 6 55–70
Peppers Mar 8 May 24 May 31 Aug 2 – Oct 11 60–90
Pole Beans Mar 22 May 24 May 31 Jul 26 – Sep 20 55–70
Potatoes Mar 22 May 24 May 31 Aug 9 – Oct 18 70–120
Pumpkin Apr 12 May 24 May 31 Aug 30 – Oct 18 85–120
Purslane Apr 12 May 3 May 17 Jul 19 Jun 28 – Aug 2 40–60
Radicchio Apr 12 May 3 May 17 Jul 19 Jul 19 – Aug 23 60–80
Radish May 3 Jul 19 May 31 – Jun 21 22–35
Rhubarb Jun 7 365–730
Romanesco Apr 12 May 3 May 17 Jul 19 Aug 2 – Sep 13 75–100
Rutabaga May 3 Jul 19 Jul 26 – Aug 30 80–100
Salsify May 3 Jul 19 Aug 16 – Sep 27 100–130
Savoy Cabbage Apr 12 May 3 May 17 Jul 19 Jul 26 – Sep 20 70–110
Scallions Apr 12 May 3 May 17 Jul 19 Jul 12 – Aug 9 50–70
Scarlet Runner Beans Mar 22 May 24 May 31 Aug 2 – Sep 6 60–80
Shallot Apr 12 May 3 May 17 Jul 19 Aug 16 – Oct 4 90–120
Shiso Mar 29 May 24 May 31 Jul 26 – Sep 20 50–70
Snap Peas Mar 22 May 24 May 31 Jul 26 – Sep 20 55–70
Snow Peas Apr 12 May 3 May 17 Jul 19 Jul 12 – Sep 6 50–65
Soybeans May 24 Aug 16 – Oct 11 80–120
Spaghetti Squash Apr 12 May 24 May 31 Aug 30 – Sep 27 85–100
Spinach Apr 12 May 3 May 17 Jul 19 Jun 21 – Aug 23 35–50
Squash (Summer) Apr 12 May 24 May 31 Jul 19 – Sep 20 45–65
Squash (Winter) Apr 12 May 24 May 31 Aug 23 – Oct 18 80–120
Sunchoke May 31 Sep 20 – Nov 15 110–150
Sweet Corn May 24 Jul 26 – Sep 6 60–90
Sweet Potatoes Mar 22 May 24 May 31 Aug 30 – Oct 18 90–120
Tatsoi Apr 12 May 3 May 17 Jul 19 Jun 21 – Jul 26 35–50
Tomatillo Mar 22 May 24 May 31 Aug 2 – Oct 11 60–85
Tomatoes Mar 22 May 24 May 31 Aug 2 – Oct 11 60–85
Turnip May 3 Jul 19 Jun 14 – Jul 19 40–60
Watercress Apr 12 May 3 May 17 Jul 19 Jun 28 – Aug 2 40–60
Watermelon Apr 12 May 24 May 31 Aug 9 – Sep 27 70–100
Wax Beans May 24 Jul 19 – Sep 13 50–65
Winter Melon Mar 22 May 24 May 31 Aug 30 – Oct 18 90–120
Yard Long Beans Mar 22 May 24 May 31 Jul 26 – Sep 6 55–80
Zucchini Apr 12 May 24 May 31 Jul 19 – Sep 13 45–60

🍓 Fruits to Grow in Carbon County

27 fruits that grow well in Zone 6a 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 7 Sep 6 – Dec 20 90–180
Aronia Jun 7 730–1095
Blackberries Jun 7 365–730
Blueberries Jun 7 730–1095
Boysenberries Jun 7 365–730
Cantaloupe Jun 7 Aug 16 – Sep 20 70–90
Che Fruit Jun 7 1095–1825
Cranberries Jun 7 730–1095
Currants Jun 7 730–1095
Elderberries Jun 7 730–1095
Goji Berries Jun 7 730–1095
Gooseberries Jun 7 730–1095
Grapes Jun 7 730–1095
Ground Cherry Jun 7 Aug 16 – Oct 11 65–80
Hardy Kiwi Jun 7 1095–1825
Haskaps Jun 7 730–1095
Honeydew Jun 7 Aug 30 – Oct 11 80–110
Jostaberry Jun 7 730–1095
Lingonberries Jun 7 730–1095
Medlar Jun 7 1095–1825
Mulberries Jun 7 730–1825
Pawpaw Jun 7 1095–2555
Persimmon Jun 7 1095–2555
Quince Jun 7 1095–1825
Raspberries Jun 7 365–730
Serviceberries Jun 7 730–1095
Strawberries Jun 7 Sep 6 – Dec 20 90–365

🌿 Herbs to Grow in Carbon County

35 herbs that grow well in Zone 6a with planting dates for Carbon County.

Show all 35 herbs with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Harvest Days to Maturity
Angelica Apr 12 May 3 May 10 Jul 19 365–730
Anise Apr 12 May 3 May 10 Jul 19 Aug 9 – Oct 25 90–120
Basil Mar 29 May 24 May 31 Jul 26 – Sep 27 50–75
Bee Balm May 24 Aug 23 – Nov 8 90–120
Borage Apr 12 May 3 May 10 Jul 19 Jul 5 – Aug 23 50–60
Caraway Apr 12 May 3 May 10 Jul 19 365–450
Catnip May 24 Jul 26 – Sep 27 60–80
Chamomile Apr 12 May 3 May 10 Jul 19 Jul 12 – Sep 20 60–90
Chervil Apr 12 May 3 May 10 Jul 19 Jun 21 – Aug 23 40–60
Chives May 24 Jul 26 – Oct 4 60–90
Cilantro Apr 12 May 3 May 10 Jul 19 Jun 21 – Aug 23 40–60
Comfrey May 24 Jul 26 – Oct 4 60–90
Cumin Apr 12 May 3 May 10 Jul 19 Aug 23 – Oct 25 100–120
Dill Apr 12 May 3 May 10 Jul 19 Jun 21 – Aug 23 40–60
Epazote Mar 29 May 24 May 31 Jul 19 – Sep 13 45–60
Fennel (herb) Apr 12 May 3 May 10 Jul 19 Jul 12 – Sep 20 60–90
Feverfew May 24 Aug 23 – Nov 8 90–120
Garlic Chives May 24 Jul 26 – Oct 4 60–90
Horehound May 24 Aug 9 – Oct 4 75–90
Hyssop May 24 Aug 2 – Oct 4 70–90
Lemon Balm May 24 Jul 26 – Sep 13 60–70
Lemon Thyme May 24 Aug 2 – Oct 4 70–90
Lovage May 24 Aug 2 – Oct 4 70–90
Marjoram May 24 Jul 26 – Oct 4 60–90
Mint May 24 Jul 26 – Oct 4 60–90
Oregano May 24 Jul 26 – Oct 4 60–90
Parsley Apr 12 May 3 May 10 Jul 19 Jul 12 – Sep 13 60–80
Rue May 24 Aug 2 – Oct 4 70–90
Sage May 24 Aug 9 – Oct 4 75–90
Savory May 24 Jul 19 – Sep 13 50–70
Sorrel Apr 12 May 3 May 10 Jul 19 Jun 21 – Aug 23 40–60
Tarragon May 24 Jul 26 – Oct 4 60–90
Thai Basil Mar 29 May 24 May 31 Jul 26 – Sep 27 50–75
Thyme May 24 Aug 2 – Oct 4 70–90
Valerian May 24 Sep 27 – Dec 6 120–180

🌸 Flowers to Grow in Carbon County

53 flowers that grow well in Zone 6a with planting dates for Carbon County.

Show all 53 flowers with planting dates
Plant Start Indoors Direct Sow Transplant Fall Plant Bloom Days to Maturity
Ageratum Mar 29 May 17 May 17 Jul 12 – Oct 18 60–75
Alliums Aug 16 Sep 13 – Oct 11 28–42
Anemones Apr 19 May 17 Jun 21 – Jul 19 90–120
Astilbe Mar 15 May 24 Aug 2 – Oct 11 70–100
Bachelor's Button Apr 5 Apr 19 May 17 Aug 16 Jul 19 – Oct 4 60–90
Begonias Mar 8 May 24 Aug 2 – Nov 1 70–90
Black-eyed Susan Mar 15 May 17 May 24 Aug 9 – Nov 22 60–80
Bleeding Hearts Mar 15 May 24 Jul 19 – Aug 23 60–90
Calendula Apr 5 Apr 19 May 17 Jul 5 – Oct 4 50–70
California Poppy Apr 19 Jun 28 – Aug 9 60–90
Celosia Apr 12 May 24 May 24 Jul 26 – Nov 8 60–90
Columbine Mar 15 May 31 May 31 Jul 26 – Aug 30 70–100
Coreopsis Mar 15 May 24 May 24 Aug 2 – Nov 22 60–80
Cosmos Apr 19 May 17 May 17 Jul 26 – Nov 1 60–90
Crocus Aug 16 Jul 5 – Jul 26 10–20
Daffodils Aug 16 Jul 12 – Aug 2 20–40
Dahlias Apr 19 May 24 May 24 Aug 9 – Nov 22 70–120
Daylily Mar 15 May 24 Aug 9 – Nov 22 60–90
Dianthus Mar 22 Apr 19 May 3 Jun 21 – Sep 20 60–80
Echinacea (Purple Coneflower) Mar 15 May 31 May 31 Aug 23 – Nov 29 70–90
Foxglove Mar 15 May 24 May 24 Jul 19 – Aug 23 80–120
Gaillardia (Blanket Flower) Mar 29 May 24 May 24 Aug 2 – Dec 6 70–100
Geraniums Mar 8 May 24 Aug 2 – Nov 1 70–100
Gladiolus May 17 May 17 Aug 2 – Nov 15 70–100
Hostas Mar 8 May 24 Aug 9 – Nov 22 60–90
Hyacinths Aug 16 Aug 2 – Aug 23 14–28
Hydrangeas Mar 8 May 24 Aug 2 – Nov 8 90–150
Impatiens Mar 22 May 24 Aug 2 – Nov 8 60–75
Irises Division May 24 Jul 19 – Aug 16 60–100
Larkspur Apr 19 Jun 28 – Aug 23 60–90
Lavender Mar 8 May 31 Aug 9 – Oct 4 90–120
Lilies Division May 24 Aug 2 – Nov 8 70–120
Lobelia Mar 15 May 3 Jun 28 – Sep 20 70–80
Lupine Mar 15 May 24 May 24 Jul 19 – Aug 23 75–100
Marigolds Apr 5 May 24 May 24 Jul 19 – Oct 18 50–70
Nasturtium Apr 19 May 24 May 24 Jul 19 – Nov 8 55–65
Pansy Mar 8 May 17 Aug 2 Jul 12 – Sep 13 70–90
Peonies Division May 24 Jul 26 – Aug 30 90–120
Petunia Mar 22 May 24 Aug 2 – Nov 8 70–90
Phlox Mar 15 May 24 May 24 Aug 2 – Oct 25 80–110
Portulaca Apr 12 May 24 May 24 Jul 12 – Oct 25 50–70
Ranunculus Apr 5 May 17 Jun 28 – Jul 26 90–120
Roses Mar 8 May 24 Aug 2 – Nov 22 90–180
Salvia Mar 15 May 24 Aug 2 – Nov 8 70–90
Sedum (Stonecrop) Mar 15 May 24 Sep 13 – Nov 29 60–90
Snapdragon Mar 8 Apr 26 May 17 Jul 26 – Oct 4 70–100
Sunflower Apr 26 May 24 May 24 Aug 16 – Nov 8 70–100
Sweet Alyssum Mar 29 Apr 26 May 17 Jun 28 – Sep 6 45–60
Sweet Pea Apr 5 Apr 12 May 17 Aug 2 – Oct 11 65–85
Tulips Aug 16 Jul 26 – Aug 23 15–30
Vinca (Annual) Mar 8 May 24 Aug 2 – Nov 8 70–90
Yarrow Mar 15 May 17 May 24 Aug 2 – Nov 22 60–90
Zinnia Apr 19 May 24 May 24 Aug 2 – 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, UT?

Carbon County is in USDA Hardiness Zone 6a. 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, UT?

Based on 31 years of NOAA weather station data, the median last spring frost in Carbon County falls around May 17. In 8 out of 10 years, last frost lands between April 29 and June 8 — a 40-day window of variability. Use June 8 as your conservative safe-to-plant date for frost-sensitive crops.

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

The median first fall frost in Carbon County arrives around September 27. In cold years it can arrive as early as September 13; in mild years as late as October 12. 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 133 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 0.57 days per decade.

What is the soil like in Carbon County for gardening?

Carbon County has predominantly Loam soil with a pH range of 6.4–8.3 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 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 Carbon County a good location for home gardening?

Carbon County scores 39/100 (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 6a). 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 (31 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.