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Shell, WY — Planting Guide for June

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Big Horn County, Wyoming Zone 5a June

Your June game plan for Big Horn County, Wyoming

A quick June briefing for Big Horn County, Wyoming gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 9
Avg. first frost October 2
Soil temp (4") 40°F
Watering Critical
Pest pressure High
Daylight 15.3 hrs
  1. Start basil, cucumber, and kale under lights

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

  2. Pick carrots, lettuce, and radish

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Looking ahead to July
  • Starting indoors: peppers, pole beans, and tomatoes
  • First harvests: basil, carrots, and cucumber
  • Fall sowing: carrots, kale, and lettuce

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Shell has a classic four-season growing climate (Zone 5a). The last spring frost typically lands around May 9 and the first fall frost arrives around October 2 — a 146-day frost-free season that's long enough for tomatoes, peppers, melons, and a full succession of cool-weather crops on either side. The trick is timing: start warm-season seedlings indoors 6–8 weeks before last frost, harden them off, and plant out the week after your local frost date is statistically safe.

Soils trend Loam — the gold standard for vegetables. Add 2–3" of compost annually to maintain it and you'll outgrow most of your neighbors.

Shell averages 30.3 drought weeks per year (US Drought Monitor, 2000–present, trend improving). Treat irrigation as a year-round system, not a summer add-on.

🌡️ USDA Zone

5a (-20°F to -15°F min)

❄️ Avg. Last Frost

May 9

🍂 Avg. First Frost

October 2

📅 Growing Season

146 days

🌧️ Climate

Moderate 23.8" annual

💨 Wind

Moderate 6.7 mph avg

🥶 Frost Tier

Regular 0% frost-free years

🏜️ Drought

30.3 wk/yr trend improving

📍 ZIP Codes

1 ZIP

Shell, WY Short season
146 days
Last Spring Frost May 9
146 growing days
First Fall Frost October 2

Monthly Watering Calendar for Shell

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

Why it matters: Plants need different amounts of water at different growth stages — heavy at flowering and fruit-set, lighter at establishment. Shell's 24" annual rainfall is your starting math; the timing tells you when natural rain will cover you and when you need to step in.

1"/wk 0" 1.3" 2.5" 3.8" 5" Jan 0.9" Feb 0.8" Mar 1.2" +2.9" Apr 1.4" +2.7" May 1.6" +3.4" Jun 0.9" +2.9" Jul 1.4" +2.7" Aug 1.6" +3.1" Sep 1.2" +3.1" Oct 1.2" Nov 0.8" 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 0.9 in 6 days None
Feb 0.8 in 6 days None
Mar 1.2 in 8 days None
Apr 1.4 in 7 days 2.9 in High
May 1.6 in 7 days 2.7 in High
Jun 0.9 in 4 days 3.4 in Critical
Jul 1.4 in 6 days 2.9 in High
Aug 1.6 in 7 days 2.7 in High
Sep 1.2 in 5 days 3.1 in Critical
Oct 1.2 in 6 days 3.1 in Critical
Nov 0.8 in 6 days None
Dec 0.8 in 6 days None

Annual total: 13.8 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.

Shell Soil Profile

Soil Type

Loam

Soil pH

6.2-7.7

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 9 → Oct 2 146 frost-free days Protect crops frost returns Apr May Jun Jul Aug Sep Oct Nov Safe: May 19 Protect by: Oct 15

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) May 19 Oct 15 149 days
Cautious May 12 Oct 8 149 days
Average year May 9 Oct 2 146 days
Optimistic May 4 Sep 21 140 days
Aggressive (risky) Apr 25 Sep 11 139 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 2.8 days per decade). Spring is arriving earlier than it used to. Good news for gardeners.

Gardening Difficulty Score

26 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
6.5/10

Big Horn 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 9 First Frost: Oct 2

Local Gardening Help in Big Horn 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 Big Horn County's climate and soil.

County Extension Office

Big Horn 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 Big Horn County

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

Why Buy Local

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

Show 6 more succession options
After Lettuce (harvest ends Aug 22) 41 days until frost
After Kale (harvest ends Aug 29) 34 days until frost
After Sweet Corn (harvest ends Aug 22) 41 days until frost
After Carrots (harvest ends Aug 15) 48 days until frost
After Alliums (harvest ends Jul 11) 83 days until frost
After Columbine (harvest ends Aug 29) 34 days until frost

Sunlight & Day Length in Shell

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

Quick context: The longest day at Shell'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

15.3 hours

Summer solstice daylight

Shortest Day

8.7 hours

Winter solstice daylight

Peak Sun Hours

11.3 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 7h 10h 14h 17h 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 hr 4.8 hr Short day
February 10.2 hr 5.7 hr Short day
March 11.6 hr 7.1 hr Short day
April 13.3 hr 8.1 hr Neutral
May 14.6 hr 8.9 hr Long day
June 15.3 hr 11.3 hr Long day
July 15 hr 10.3 hr Long day
August 13.9 hr 9.4 hr Neutral
September 12.3 hr 8.5 hr Neutral
October 10.7 hr 6.9 hr Short day
November 9.3 hr 5.2 hr Short day
December 8.7 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 Shell

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

The practical takeaway: Cold soil = stunted starts. A bean seed planted in 55°F soil rots before it germinates. Same seed in 65°F soil sprouts in 5 days. Shell's soil temperature pattern shows you the difference month to month.

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 -10°F -1°F ❄️ Dormant ~36 weeks
Feb -6°F 1°F ❄️ Dormant ~36 weeks
Mar 2°F 6°F ❄️ Dormant ~36 weeks
Apr 17°F 16°F ❄️ Dormant ~36 weeks
May 31°F 27°F ❄️ Dormant ~36 weeks
Jun 40°F 36°F 🐢 Slow ~24 weeks
Jul 51°F 44°F ♻️ Active ~14 weeks
Aug 52°F 47°F ♻️ Active ~14 weeks
Sep 43°F 40°F 🐢 Slow ~24 weeks
Oct 29°F 32°F ❄️ Dormant ~36 weeks
Nov 12°F 20°F ❄️ Dormant ~36 weeks
Dec -2°F 7°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 Shell

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

Quick context: Pest score isn't pass/fail. It's a planning input. Higher scores mean: more compost (resilient plants), wider spacing (air circulation), resistant varieties (built-in defense), and inspection (catch issues at egg stage).

Insect Pest Pressure

4.7 / 10

Moderate — common pests appear but manageable with monitoring.

Disease Risk

1.6 / 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 Low 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 Shell

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

What this means for you: Bare soil is wasted soil — it loses nutrients to rain, dries out, compacts, and gets taken over by weeds. Cover crops (clovers, ryegrass, vetch, peas) are the "between seasons" trick that makes soil better every year. In Shell, you can fit a cover crop into the gaps.

Spring Cover Crops (2 options) — Build soil before the main growing season
Crop Plant By Terminate N-Fixing Soil Benefit
Buckwheat May 16 Aug 7 Rapid growth, attracts pollinators, suppresses weeds
White clover Apr 13 Jul 31 ✓ 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 5 Sep 11 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 20 Apr 18 Deep taproot breaks compaction, excellent for clay soils
Hairy vetch Jul 12 Apr 18 ✓ Yes Excellent nitrogen fixer, good for depleted soils
Oats Aug 30 Apr 18 Quick biomass, winterkills in cold zones — no spring tillage needed
Winter rye Jun 23 Apr 25 Suppresses weeds, prevents erosion, breaks up compacted soil
Winter wheat Jun 23 Apr 25 Erosion control, weed suppression, good biomass

Wind & Microclimate in Shell

Why it matters: Light wind is good (strengthens stems, aids pollination); strong wind is bad (snaps stems, dries leaves, scatters seeds). Shell averages 6.7 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: 14 mph   Summer: 10 mph

Fall: 12 mph   Winter: 17 mph

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

Windbreak Benefit

6.9/10

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

Frost Pocket Risk

High

Hilly terrain with 2,368 ft of elevation range — cold air pools in low spots. Avoid planting frost-sensitive crops in valleys.

Rainwater Harvesting in Shell

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

What this means for you: Rainwater scales linearly with roof area. A 2,000 sq ft roof in Shell captures ~1,200 gallons per 1" of rain — given 24" annual rainfall, that's thousands of gallons a year if you have storage to hold it.

Annual Collection

6,877 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

Unrestricted

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

Best Collection Months

Apr, May, Jul, Aug

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

Months to Draw From Storage

Jan, Feb, Jun, 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 13.8 inches of rain per year
  • A 1,000 sq ft roof can collect roughly 6,877 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

🥬 Vegetables to Grow in Shell

105 vegetables matched to Zone 5a with planting dates calibrated for Shell.

Show all 105 vegetables with dates
Plant Start Indoors Direct Sow Transplant Fall Plant Harvest Days to Maturity
Acorn Squash Apr 4 May 16 May 23 Aug 15 – Sep 19 80–100
Amaranth Mar 14 May 16 May 23 Aug 22 – Oct 10 90–120
Arugula Apr 4 Apr 25 May 9 Jul 24 Jun 13 – Aug 15 30–50
Asparagus May 23 730–1095
Beets Apr 25 Jul 24 Jun 20 – Jul 18 50–70
Belgian Endive Apr 4 Apr 25 May 9 Jul 24 Aug 29 – Oct 24 110–150
Bitter Melon Mar 14 May 16 May 23 Jul 25 – Sep 5 60–90
Black Beans May 16 Aug 15 – Oct 3 90–120
Bok Choy Apr 4 Apr 25 May 9 Jul 24 Jun 20 – Jul 25 40–60
Broccoli Apr 4 Apr 25 May 9 Jul 24 Jul 11 – Aug 22 60–90
Broccoli Rabe Apr 4 Apr 25 May 9 Jul 24 Jun 20 – Jul 25 40–60
Brussels Sprouts Apr 4 Apr 25 May 9 Jul 24 Aug 8 – Oct 3 90–130
Butternut Squash Apr 4 May 16 May 23 Aug 22 – Sep 26 85–110
Cabbage Apr 4 Apr 25 May 9 Jul 24 Jul 11 – Sep 5 60–100
Calabash Mar 14 May 16 May 23 Aug 15 – Oct 10 80–120
Carrots Apr 25 Jul 24 Jun 27 – Aug 1 60–80
Cauliflower Apr 4 Apr 25 May 9 Jul 24 Jul 4 – Sep 5 55–100
Celeriac Apr 4 Apr 25 May 9 Jul 24 Aug 22 – Sep 26 100–120
Celery Apr 4 Apr 25 May 9 Jul 24 Aug 1 – Sep 26 80–120
Celtuce Apr 4 Apr 25 May 9 Jul 24 Jul 11 – Aug 22 60–90
Chard Apr 4 Apr 25 May 9 Jul 24 Jul 4 – Aug 22 50–60
Chickpeas Apr 4 Apr 25 May 9 Jul 24 Aug 1 – Sep 12 80–110
Chicory Apr 4 Apr 25 May 9 Jul 24 Jul 11 – Aug 22 60–85
Chinese Cabbage Apr 4 Apr 25 May 9 Jul 24 Jul 4 – Aug 1 50–70
Christmas Lima Beans Mar 14 May 16 May 23 Aug 15 – Sep 19 80–100
Collard Greens Apr 4 Apr 25 May 9 Jul 24 Jul 4 – Sep 5 55–75
Corn May 16 Jul 18 – Sep 12 60–100
Cowpeas May 16 Jul 18 – Aug 29 60–90
Cress Apr 4 Apr 25 May 9 Jul 24 May 23 – Jun 13 14–21
Crookneck Squash Apr 4 May 16 May 23 Jul 11 – Aug 8 45–60
Crosne Apr 25 Jul 24 Sep 26 – Oct 10 150–200
Cucumber Apr 4 May 16 May 23 Jul 18 – Sep 12 50–70
Daikon Apr 25 Jul 24 Jun 20 – Jul 18 50–70
Delicata Squash Apr 4 May 16 May 23 Aug 15 – Sep 19 80–100
Edamame May 16 Aug 1 – Sep 12 75–100
Eggplant Feb 28 May 16 May 23 Aug 1 – Oct 3 65–85
Endive Apr 4 Apr 25 May 9 Jul 24 Jun 27 – Aug 1 45–65
Escarole Apr 4 Apr 25 May 9 Jul 24 Jul 4 – Aug 1 50–70
Fava Beans Apr 4 Apr 25 May 9 Jul 24 Jul 25 – Sep 5 75–100
Fennel Mar 14 May 16 May 23 Jul 25 – Sep 5 60–90
Garlic Aug 21 Nov 20 – Feb 5 90–240
Green Beans May 16 Jul 11 – Sep 5 50–65
Horseradish May 23 Sep 26 – Nov 7 120–180
Hot Peppers Feb 28 May 16 May 23 Aug 1 – Nov 7 70–120
Hubbard Squash Apr 4 May 16 May 23 Sep 5 – Oct 10 100–120
Kabocha Apr 4 May 16 May 23 Aug 22 – Sep 19 85–100
Kai Lan Apr 4 Apr 25 May 9 Jul 24 Jun 27 – Jul 25 45–60
Kale Apr 4 Apr 25 May 9 Jul 24 Jul 4 – Aug 29 50–70
Kidney Beans May 16 Aug 15 – Sep 19 85–110
Kohlrabi Apr 4 Apr 25 May 9 Jul 24 Jun 27 – Aug 1 45–65
Komatsuna Apr 4 Apr 25 May 9 Jul 24 Jun 13 – Jul 18 35–50
Leeks Apr 4 Apr 25 May 9 Jul 24 Aug 8 – Oct 24 90–150
Lentils Apr 4 Apr 25 May 9 Jul 24 Aug 1 – Sep 12 80–110
Lettuce Apr 4 Apr 25 May 9 Jul 24 Jun 13 – Aug 22 30–60
Lima Beans May 16 Jul 18 – Aug 29 60–90
Mache Apr 4 Apr 25 May 9 Jul 24 Jun 20 – Jul 25 40–60
Melon Apr 4 May 16 May 23 Aug 1 – Sep 19 70–100
Microgreens Apr 4 Apr 25 May 9 Jul 24 May 16 – Jun 13 7–21
Mitsuba Apr 4 Apr 25 May 2 Jul 24 Jun 27 – Aug 22 50–70
Mizuna Apr 4 Apr 25 May 9 Jul 24 Jun 13 – Jul 11 30–45
Mustard Greens Apr 4 Apr 25 May 9 Jul 24 Jun 13 – Aug 15 30–50
Napa Cabbage Apr 4 Apr 25 May 9 Jul 24 Jul 4 – Aug 8 55–75
New Zealand Spinach Mar 14 May 16 May 23 Jul 18 – Aug 15 55–70
Okra Mar 14 May 16 May 23 Jul 18 – Sep 12 50–65
Onion Apr 4 Apr 25 May 9 Jul 24 Aug 8 – Sep 26 90–120
Pac Choi Apr 4 Apr 25 May 9 Jul 24 Jun 20 – Jul 18 40–55
Parsnip Apr 25 Jul 24 Aug 8 – Sep 19 100–130
Patty Pan Squash Apr 4 May 16 May 23 Jul 11 – Aug 8 45–60
Peas Apr 4 Apr 25 May 9 Jul 24 Jul 4 – Aug 29 55–70
Peppers Feb 28 May 16 May 23 Jul 25 – Oct 3 60–90
Pole Beans Mar 14 May 16 May 23 Jul 18 – Sep 12 55–70
Potatoes Mar 14 May 16 May 23 Aug 1 – Oct 10 70–120
Pumpkin Apr 4 May 16 May 23 Aug 22 – Oct 10 85–120
Purslane Apr 4 Apr 25 May 9 Jul 24 Jun 20 – Jul 25 40–60
Radicchio Apr 4 Apr 25 May 9 Jul 24 Jul 11 – Aug 15 60–80
Radish Apr 25 Jul 24 May 23 – Jun 13 22–35
Rhubarb May 30 365–730
Romanesco Apr 4 Apr 25 May 9 Jul 24 Jul 25 – Sep 5 75–100
Rutabaga Apr 25 Jul 24 Jul 18 – Aug 22 80–100
Salsify Apr 25 Jul 24 Aug 8 – Sep 19 100–130
Savoy Cabbage Apr 4 Apr 25 May 9 Jul 24 Jul 18 – Sep 12 70–110
Scallions Apr 4 Apr 25 May 9 Jul 24 Jul 4 – Aug 1 50–70
Scarlet Runner Beans Mar 14 May 16 May 23 Jul 25 – Aug 29 60–80
Shallot Apr 4 Apr 25 May 9 Jul 24 Aug 8 – Sep 26 90–120
Shiso Mar 21 May 16 May 23 Jul 18 – Sep 12 50–70
Snap Peas Mar 14 May 16 May 23 Jul 18 – Sep 12 55–70
Snow Peas Apr 4 Apr 25 May 9 Jul 24 Jul 4 – Aug 29 50–65
Soybeans May 16 Aug 8 – Oct 3 80–120
Spaghetti Squash Apr 4 May 16 May 23 Aug 22 – Sep 19 85–100
Spinach Apr 4 Apr 25 May 9 Jul 24 Jun 13 – Aug 15 35–50
Squash (Summer) Apr 4 May 16 May 23 Jul 11 – Sep 12 45–65
Squash (Winter) Apr 4 May 16 May 23 Aug 15 – Oct 10 80–120
Sunchoke May 23 Sep 12 – Nov 7 110–150
Sweet Corn May 16 Jul 18 – Aug 29 60–90
Sweet Potatoes Mar 14 May 16 May 23 Aug 22 – Oct 10 90–120
Tatsoi Apr 4 Apr 25 May 9 Jul 24 Jun 13 – Jul 18 35–50
Tomatillo Mar 14 May 16 May 23 Jul 25 – Oct 3 60–85
Tomatoes Mar 14 May 16 May 23 Jul 25 – Oct 3 60–85
Turnip Apr 25 Jul 24 Jun 6 – Jul 11 40–60
Watercress Apr 4 Apr 25 May 9 Jul 24 Jun 20 – Jul 25 40–60
Watermelon Apr 4 May 16 May 23 Aug 1 – Sep 19 70–100
Wax Beans May 16 Jul 11 – Sep 5 50–65
Winter Melon Mar 14 May 16 May 23 Aug 22 – Oct 10 90–120
Yard Long Beans Mar 14 May 16 May 23 Jul 18 – Aug 29 55–80
Zucchini Apr 4 May 16 May 23 Jul 11 – Sep 5 45–60

🍓 Fruits to Grow in Shell

27 fruits matched to Zone 5a with planting dates calibrated for Shell.

Show all 27 fruits with dates
Plant Start Indoors Direct Sow Transplant Fall Plant Harvest Days to Maturity
Alpine Strawberries May 30 Aug 29 – Nov 14 90–180
Aronia May 30 730–1095
Blackberries May 30 365–730
Blueberries May 30 730–1095
Boysenberries May 30 365–730
Cantaloupe May 30 Aug 8 – Sep 12 70–90
Che Fruit May 30 1095–1825
Cranberries May 30 730–1095
Currants May 30 730–1095
Elderberries May 30 730–1095
Goji Berries May 30 730–1095
Gooseberries May 30 730–1095
Grapes May 30 730–1095
Ground Cherry May 30 Aug 8 – Oct 3 65–80
Hardy Kiwi May 30 1095–1825
Haskaps May 30 730–1095
Honeydew May 30 Aug 22 – Oct 3 80–110
Jostaberry May 30 730–1095
Lingonberries May 30 730–1095
Medlar May 30 1095–1825
Mulberries May 30 730–1825
Pawpaw May 30 1095–2555
Persimmon May 30 1095–2555
Quince May 30 1095–1825
Raspberries May 30 365–730
Serviceberries May 30 730–1095
Strawberries May 30 Aug 29 – Nov 14 90–365

🌿 Herbs to Grow in Shell

34 herbs matched to Zone 5a with planting dates calibrated for Shell.

Show all 34 herbs with dates
Plant Start Indoors Direct Sow Transplant Fall Plant Harvest Days to Maturity
Angelica Apr 4 Apr 25 May 2 Jul 24 365–730
Anise Apr 4 Apr 25 May 2 Jul 24 Aug 1 – Oct 17 90–120
Basil Mar 21 May 16 May 23 Jul 18 – Sep 19 50–75
Bee Balm May 16 Aug 15 – Oct 31 90–120
Borage Apr 4 Apr 25 May 2 Jul 24 Jun 27 – Aug 15 50–60
Caraway Apr 4 Apr 25 May 2 Jul 24 365–450
Catnip May 16 Jul 18 – Sep 19 60–80
Chamomile Apr 4 Apr 25 May 2 Jul 24 Jul 4 – Sep 12 60–90
Chervil Apr 4 Apr 25 May 2 Jul 24 Jun 13 – Aug 15 40–60
Chives May 16 Jul 18 – Sep 26 60–90
Cilantro Apr 4 Apr 25 May 2 Jul 24 Jun 13 – Aug 15 40–60
Comfrey May 16 Jul 18 – Sep 26 60–90
Cumin Apr 4 Apr 25 May 2 Jul 24 Aug 15 – Oct 17 100–120
Dill Apr 4 Apr 25 May 2 Jul 24 Jun 13 – Aug 15 40–60
Epazote Mar 21 May 16 May 23 Jul 11 – Sep 5 45–60
Fennel (herb) Apr 4 Apr 25 May 2 Jul 24 Jul 4 – Sep 12 60–90
Feverfew May 16 Aug 15 – Oct 31 90–120
Garlic Chives May 16 Jul 18 – Sep 26 60–90
Horehound May 16 Aug 1 – Sep 26 75–90
Hyssop May 16 Jul 25 – Sep 26 70–90
Lemon Balm May 16 Jul 18 – Sep 5 60–70
Lemon Thyme May 16 Jul 25 – Sep 26 70–90
Lovage May 16 Jul 25 – Sep 26 70–90
Mint May 16 Jul 18 – Sep 26 60–90
Oregano May 16 Jul 18 – Sep 26 60–90
Parsley Apr 4 Apr 25 May 2 Jul 24 Jul 4 – Sep 5 60–80
Rue May 16 Jul 25 – Sep 26 70–90
Sage May 16 Aug 1 – Sep 26 75–90
Savory May 16 Jul 11 – Sep 5 50–70
Sorrel Apr 4 Apr 25 May 2 Jul 24 Jun 13 – Aug 15 40–60
Tarragon May 16 Jul 18 – Sep 26 60–90
Thai Basil Mar 21 May 16 May 23 Jul 18 – Sep 19 50–75
Thyme May 16 Jul 25 – Sep 26 70–90
Valerian May 16 Sep 19 – Oct 31 120–180

🌸 Flowers to Grow in Shell

51 flowers matched to Zone 5a with planting dates calibrated for Shell.

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

Monthly Planting Guide for Shell

ZIP Codes in Shell

Click any ZIP to see its specific frost, soil, and climate measurements (some ZIPs differ noticeably from the town aggregate):

Gardening Guides & Resources

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

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Your Big Horn County Garden Planner — Free

A 22-page printable planner built for Big Horn 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.

Instant PDF download. No spam, unsubscribe any time.

Best Seller
The Gardener's Encyclopedia to Companion Planting

The Gardener's Encyclopedia to Companion Planting

$27 $293 value

The pairings that make vegetables, herbs, and flowers grow better — and the ones that quietly wreck a bed.

  • Proven pairings for 200+ vegetables, herbs, flowers, and fruits
  • Full seed-starting + planting schedule with timing and spacing
  • Bonus: square-foot gardening guide + printable seasonal planners
See what's inside →
Reader favourite
Seed Saving & Storage Guide

Seed Saving & Storage Guide

$27 $157 value

Most saved seeds go bad before next season. This shows exactly when to pick, how to dry, and where to store seeds from 200 plants so yours don't.

  • 200 plants, step-by-step: life cycle, pollination type, isolation
  • Exact temperature + humidity ranges that keep seeds viable
  • Bonus: searchable Google Sheets tracker + custom GPT assistant
Save a lifetime of seed money →
Composting Guide for Homesteaders

Composting Guide for Homesteaders

$27 $210 value

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.

  • 14 sections on composting methods, soil science, and troubleshooting
  • The 7-step hot-compost system from start to finish
  • Bonus tools: troubleshooting chart, safety guide, monitoring log
Start composting today →

Town-level data is aggregated from per-ZIP NOAA GHCN-D measurements (1 ZIP code in Shell), USDA SSURGO soil survey, and the US Drought Monitor weekly archive. Frost dates represent 50% probability averages; local conditions vary by elevation and microclimate. Last updated: June 2026.