Yellowstone County, MT — Planting Guide
What to do in July
July rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Yellowstone County, Montana.
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Indoor seed-starting week for peppers, pole beans, and tomatoes
These need a head start before your last frost (May 9). Sow into cells now so you're ready to transplant in a few weeks.
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Start harvesting basil, carrots, and cucumber
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
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Plant your fall garden: carrots, kale, and lettuce
Your first frost is about 12 weeks away — plenty of time for these to mature.
Get ahead of August
- First harvests: basil, carrots, and cucumber
- Fall sowing: alliums, crocus, and daffodils
Yellowstone County is in USDA Zone 5a. The average last spring frost is May 9 and the first fall frost is October 3, giving you a growing season of approximately 147 days.
At an elevation of 7,432 ft, Yellowstone County receives approximately 21.1 in of rainfall annually. Summer highs average 80°F with winter lows around 9°F. The predominant soil type is Loam.
Based on 31 years of NOAA climate station data, the last frost date here varies by 28 days year to year — ranging from April 24 in warm years to May 22 in cold years. The growing season is trending longer by about 2.75 days per decade. Yellowstone County scores 30/100 (Challenging) on the Microclimate Index.
🌡️ Zone
5a (-20°F to -15°F min)
❄️ Last Frost
May 9
🍂 First Frost
October 3
📅 Growing Season
147 days
⛰️ Elevation
7,432 ft
🌧️ Annual Rainfall
21.1 in
Monthly Watering Calendar for Yellowstone 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: In humid climates, watering is usually about timing (morning, not evening, to prevent disease) more than volume. In dry climates, it's about depth (water deep, less often) more than frequency. Yellowstone County's 21" annual tells you which side you're on.
View detailed monthly data
| Month | Avg Rainfall | Rainy Days | Extra Water Needed | Watering Effort |
|---|---|---|---|---|
| Jan | 1.3 in | 7 days | — | None |
| Feb | 1.2 in | 5 days | — | None |
| Mar | 1.9 in | 7 days | — | None |
| Apr | 1.9 in | 8 days | 2.4 in | High |
| May | 2.7 in | 8 days | 1.6 in | High |
| Jun | 1.7 in | 5 days | 2.6 in | High |
| Jul | 1.7 in | 5 days | 2.6 in | High |
| Aug | 2.5 in | 7 days | 1.8 in | High |
| Sep | 1.7 in | 6 days | 2.6 in | High |
| Oct | 1.8 in | 5 days | 2.5 in | High |
| Nov | 1.6 in | 5 days | — | None |
| Dec | 1.2 in | 6 days | — | None |
Annual total: 21.2 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.
Yellowstone County Soil Profile
Soil Type
Loam
Soil pH
6.2-8
Drainage
Well Drained
Frost Risk Probability
Based on 31 years of NOAA weather station data from 3 stations
Beginners: Plant frost-sensitive crops (tomatoes, peppers, squash) after the "Safe" date on the left. Harvest or cover them before the "Protect by" date on the right. Hardy crops (lettuce, peas, kale) can go in the yellow transition zones.
How to read this table: "Conservative" means you're safe from frost 9 out of 10 years — best for beginners and frost-sensitive crops. "Average year" is the typical date. "Aggressive" means only 1 in 10 years is that warm — experienced gardeners with frost protection can try these dates.
| Planting Strategy | Last Spring Frost | First Fall Frost | Frost-Free Days |
|---|---|---|---|
| Conservative (safest) | May 22 | Oct 18 | 149 days |
| Cautious | May 14 | Oct 10 | 149 days |
| Average year | May 9 | Oct 3 | 147 days |
| Optimistic | May 4 | Sep 22 | 141 days |
| Aggressive (risky) | Apr 24 | Sep 12 | 141 days |
Not very — frost dates can vary by ±28 days year-to-year. Use the "Conservative" row in the table below, and keep row covers handy for surprise late frosts.
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
Yellowstone County has challenging growing conditions. Season extension and careful variety selection are essential.
Local Gardening Help in Yellowstone 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 Yellowstone County's climate and soil.
County Extension Office
Yellowstone County Montana State University Extension Extension Office
Phone: 406-994-3402
Visit Extension Office Website →
Extension offices are run by land-grant universities and funded by the USDA. Their advice is free, research-based, and tailored to your county's specific conditions.
Master Gardener Program
Free gardening help from trained volunteers
Master Gardeners are community volunteers who complete 40–60 hours of university horticultural training. They answer gardening questions, diagnose plant problems, and offer workshops — all free.
Many extension offices run a Master Gardener hotline where you can call or email with photos of plant problems for free diagnosis.
Soil Testing
Available through your extension office
Before amending your soil, get it tested. Your extension office offers soil testing (typically $10–$25) that tells you exact pH, nutrient levels, and amendment recommendations specific to what you want to grow.
Services Available in Yellowstone County
Finding local nurseries & garden centers in Yellowstone County
Why Buy Local
Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Yellowstone 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 Yellowstone County MT" or "garden center Yellowstone 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 Yellowstone County MT" or check your extension office and local parks department. Facebook groups like "Yellowstone County Gardeners" or "Montana 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
Sunlight & Day Length in Yellowstone County
Monthly daylight hours and peak sun — critical for onion varieties, photoperiod-sensitive plants, and solar garden planning.
Why this matters: Day length is the trigger that tells lettuce, spinach, and cilantro to bolt. In Yellowstone County, knowing when that day-length threshold arrives helps you plant a final round in time to harvest before it bolts.
Longest Day
15.5 hours
Summer solstice daylight
Shortest Day
8.5 hours
Winter solstice daylight
Peak Sun Hours
10.8 hr/day peak (summer)
Peak sun hours (green dashed line below) account for cloud cover — this is the usable direct sunlight your garden actually receives. Most vegetables need 6+ peak sun hours.
Onion tip: Your long summer days (14+ hours) support long-day onion varieties like Walla Walla, Sweet Spanish, and Ailsa Craig.
View detailed monthly data
| Month | Daylight Hours | Peak Sun Hours | Day Length |
|---|---|---|---|
| January | 8.8 hr | 4.6 hr | Short day |
| February | 10.1 hr | 5.9 hr | Short day |
| March | 11.6 hr | 7 hr | Short day |
| April | 13.3 hr | 7.6 hr | Neutral |
| May | 14.7 hr | 9.3 hr | Long day |
| June | 15.5 hr | 10.8 hr | Long day |
| July | 15.2 hr | 10.1 hr | Long day |
| August | 14 hr | 9.7 hr | Long day |
| September | 12.3 hr | 8.9 hr | Neutral |
| October | 10.7 hr | 7 hr | Short day |
| November | 9.2 hr | 5.6 hr | Short day |
| December | 8.5 hr | 4.7 hr | Short day |
Peak sun hours factor in typical cloud cover — use these for solar panel and shade-planning calculations.
Soil Temperature & Composting in Yellowstone County
Monthly soil temps tell you when to plant warm-season crops, and when your compost pile is actively working.
Quick context: Watching soil temperature (not air) is the single biggest upgrade most new gardeners can make. Yellowstone County's typical curve helps you plan — but a $5 soil thermometer in the bed beats any average.
Plant Warm Crops When
Soil reaches 60°F+
Soil rarely reaches 60°F — use black plastic mulch to warm soil.
Best Month to Compost
Aug
Microbial activity peaks when soil is warm.
Active Composting
1 months
Short season — insulate pile or use indoor vermicomposting.
View detailed monthly data
| Month | Soil 4" Deep | Soil 8" Deep | Compost Activity | Time to Finish |
|---|---|---|---|---|
| Jan | -10°F | 1°F | ❄️ Dormant | ~36 weeks |
| Feb | -6°F | -0°F | ❄️ Dormant | ~36 weeks |
| Mar | 4°F | 5°F | ❄️ Dormant | ~36 weeks |
| Apr | 16°F | 17°F | ❄️ Dormant | ~36 weeks |
| May | 33°F | 28°F | ❄️ Dormant | ~36 weeks |
| Jun | 44°F | 37°F | 🐢 Slow | ~24 weeks |
| Jul | 49°F | 42°F | 🐢 Slow | ~24 weeks |
| Aug | 53°F | 47°F | ♻️ Active | ~14 weeks |
| Sep | 43°F | 42°F | 🐢 Slow | ~24 weeks |
| Oct | 29°F | 32°F | ❄️ Dormant | ~36 weeks |
| Nov | 16°F | 21°F | ❄️ Dormant | ~36 weeks |
| Dec | 0°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 Yellowstone County
Computed from local climate patterns — warmer, humid conditions increase pest generations and fungal disease risk.
Quick context: Warm humid regions cycle through pest generations 3-5x faster than cold dry regions. Yellowstone 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
Moderate — common pests appear but manageable with monitoring.
Disease Risk
Low disease risk — dry conditions reduce fungal problems.
Seasonal Risk
View 5 common pests in your area
| Pest | Risk Level | Peak Months |
|---|---|---|
| Aphids | Moderate | May, Jun, Jul, Aug |
| Cabbage worms | Low | Jun, Jul, Aug |
| Colorado potato beetle | Moderate | Jun, Jul |
| Flea beetles | Low | May, Jun, Jul |
| Slugs | Low | May, Jun, Jul, Aug, Sep |
Organic pest management tips
- Maintain healthy soil with regular compost additions to build natural pest resistance
- Practice crop rotation annually to break pest cycles
- Encourage beneficial insects with flowering herbs like dill, fennel, and yarrow
Cover Crops for Yellowstone County
Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with planting dates calibrated for your area.
Why it matters: 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 Yellowstone County, 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 10 | Aug 8 | — | Rapid growth, attracts pollinators, suppresses weeds |
| White clover | Apr 13 | Aug 8 | ✓ 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 2 | Sep 12 | — | 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 24 | Apr 18 | — | Deep taproot breaks compaction, excellent for clay soils |
| Hairy vetch | Jul 14 | Apr 25 | ✓ Yes | Excellent nitrogen fixer, good for depleted soils |
| Oats | Aug 23 | Apr 25 | — | Quick biomass, winterkills in cold zones — no spring tillage needed |
| Winter rye | Jul 8 | Apr 18 | — | Suppresses weeds, prevents erosion, breaks up compacted soil |
| Winter wheat | Jul 14 | Apr 25 | — | Erosion control, weed suppression, good biomass |
Wind & Microclimate in Yellowstone County
The practical takeaway: Pollinators avoid windy days. Yellowstone County's 11.1 mph average wind isn't enough to stop bees and butterflies — but plant fruiting crops (tomatoes, peppers, squash) in protected microclimates and you'll see noticeably better fruit set.
Wind dries soil, stresses plants, and affects frost patterns. Understanding your exposure helps with garden placement.
Seasonal Wind Speed
Spring: 14 mph Summer: 11 mph
Fall: 12 mph Winter: 15 mph
Prevailing wind: W. Windy area — plant a windbreak hedge on the W side of your garden.
Windbreak Benefit
7.2/10
Strongly recommended — a windbreak (fence, hedge, or row of tall crops like corn or sunflowers) will significantly improve garden yields.
Frost Pocket Risk
High
Hilly terrain with 1,067 ft of elevation range — cold air pools in low spots. Avoid planting frost-sensitive crops in valleys.
Rainwater Harvesting in Yellowstone County
How much water you can collect, when to collect it, and what size system you need for your garden.
The practical takeaway: Even in arid regions, rainwater harvesting works — you just need bigger storage and patience. In wet regions like Yellowstone County (21" annually), you're mostly limited by how much water you can store between storms.
Annual Collection
10,566 gal
Per 1,000 sq ft of roof area (at 80% collection efficiency)
Recommended Setup
7 rain barrels (55 gal each)
For a typical 500 sq ft garden. Serious collectors: consider a 1,750 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
Jan, Feb, Dec
Dry months when you'll rely on stored water — size your storage for this gap.
Rainwater collection tips for your area
- Your county receives approximately 21.2 inches of rain per year
- A 1,000 sq ft roof can collect roughly 10,566 gallons annually
- Rainwater harvesting is fully legal in your state
- Stock up on stored water before your dry season (Jan, Feb, Dec)
- Use a first-flush diverter to keep roof debris out of your collection
Soil & Growing Conditions in Yellowstone County
Soil Type
Loam
Soil pH 6.2–8 · Excessively 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
147-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.
Recommended for Your Garden
Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.
Get instant, accurate soil pH readings to fine-tune your amendments.
Boost soil fertility and structure with rich, well-aged organic compost.
🥬 Vegetables to Grow in Yellowstone County
105 vegetables that grow well in Zone 5a with planting dates for Yellowstone County.
Show all 105 vegetables with planting 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 25 | Jun 13 – Aug 15 | 30–50 |
| Asparagus | — | — | May 23 | — | — | 730–1095 |
| Beets | — | Apr 25 | — | Jul 25 | Jun 20 – Jul 18 | 50–70 |
| Belgian Endive | Apr 4 | Apr 25 | May 9 | Jul 25 | 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 25 | Jun 20 – Jul 25 | 40–60 |
| Broccoli | Apr 4 | Apr 25 | May 9 | Jul 25 | Jul 11 – Aug 22 | 60–90 |
| Broccoli Rabe | Apr 4 | Apr 25 | May 9 | Jul 25 | Jun 20 – Jul 25 | 40–60 |
| Brussels Sprouts | Apr 4 | Apr 25 | May 9 | Jul 25 | 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 25 | Jul 11 – Sep 5 | 60–100 |
| Calabash | Mar 14 | May 16 | May 23 | — | Aug 15 – Oct 10 | 80–120 |
| Carrots | — | Apr 25 | — | Jul 25 | Jun 27 – Aug 1 | 60–80 |
| Cauliflower | Apr 4 | Apr 25 | May 9 | Jul 25 | Jul 4 – Sep 5 | 55–100 |
| Celeriac | Apr 4 | Apr 25 | May 9 | Jul 25 | Aug 22 – Sep 26 | 100–120 |
| Celery | Apr 4 | Apr 25 | May 9 | Jul 25 | Aug 1 – Sep 26 | 80–120 |
| Celtuce | Apr 4 | Apr 25 | May 9 | Jul 25 | Jul 11 – Aug 22 | 60–90 |
| Chard | Apr 4 | Apr 25 | May 9 | Jul 25 | Jul 4 – Aug 22 | 50–60 |
| Chickpeas | Apr 4 | Apr 25 | May 9 | Jul 25 | Aug 1 – Sep 12 | 80–110 |
| Chicory | Apr 4 | Apr 25 | May 9 | Jul 25 | Jul 11 – Aug 22 | 60–85 |
| Chinese Cabbage | Apr 4 | Apr 25 | May 9 | Jul 25 | 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 25 | 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 25 | May 23 – Jun 13 | 14–21 |
| Crookneck Squash | Apr 4 | May 16 | May 23 | — | Jul 11 – Aug 8 | 45–60 |
| Crosne | — | Apr 25 | — | Jul 25 | Sep 26 – Oct 10 | 150–200 |
| Cucumber | Apr 4 | May 16 | May 23 | — | Jul 18 – Sep 12 | 50–70 |
| Daikon | — | Apr 25 | — | Jul 25 | 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 25 | Jun 27 – Aug 1 | 45–65 |
| Escarole | Apr 4 | Apr 25 | May 9 | Jul 25 | Jul 4 – Aug 1 | 50–70 |
| Fava Beans | Apr 4 | Apr 25 | May 9 | Jul 25 | Jul 25 – Sep 5 | 75–100 |
| Fennel | Mar 14 | May 16 | May 23 | — | Jul 25 – Sep 5 | 60–90 |
| Garlic | — | — | — | Aug 22 | Nov 21 – Feb 6 | 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 25 | Jun 27 – Jul 25 | 45–60 |
| Kale | Apr 4 | Apr 25 | May 9 | Jul 25 | Jul 4 – Aug 29 | 50–70 |
| Kidney Beans | — | May 16 | — | — | Aug 15 – Sep 19 | 85–110 |
| Kohlrabi | Apr 4 | Apr 25 | May 9 | Jul 25 | Jun 27 – Aug 1 | 45–65 |
| Komatsuna | Apr 4 | Apr 25 | May 9 | Jul 25 | Jun 13 – Jul 18 | 35–50 |
| Leeks | Apr 4 | Apr 25 | May 9 | Jul 25 | Aug 8 – Oct 24 | 90–150 |
| Lentils | Apr 4 | Apr 25 | May 9 | Jul 25 | Aug 1 – Sep 12 | 80–110 |
| Lettuce | Apr 4 | Apr 25 | May 9 | Jul 25 | Jun 13 – Aug 22 | 30–60 |
| Lima Beans | — | May 16 | — | — | Jul 18 – Aug 29 | 60–90 |
| Mache | Apr 4 | Apr 25 | May 9 | Jul 25 | 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 25 | May 16 – Jun 13 | 7–21 |
| Mitsuba | Apr 4 | Apr 25 | May 2 | Jul 25 | Jun 27 – Aug 22 | 50–70 |
| Mizuna | Apr 4 | Apr 25 | May 9 | Jul 25 | Jun 13 – Jul 11 | 30–45 |
| Mustard Greens | Apr 4 | Apr 25 | May 9 | Jul 25 | Jun 13 – Aug 15 | 30–50 |
| Napa Cabbage | Apr 4 | Apr 25 | May 9 | Jul 25 | 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 25 | Aug 8 – Sep 26 | 90–120 |
| Pac Choi | Apr 4 | Apr 25 | May 9 | Jul 25 | Jun 20 – Jul 18 | 40–55 |
| Parsnip | — | Apr 25 | — | Jul 25 | 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 25 | 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 25 | Jun 20 – Jul 25 | 40–60 |
| Radicchio | Apr 4 | Apr 25 | May 9 | Jul 25 | Jul 11 – Aug 15 | 60–80 |
| Radish | — | Apr 25 | — | Jul 25 | May 23 – Jun 13 | 22–35 |
| Rhubarb | — | — | May 30 | — | — | 365–730 |
| Romanesco | Apr 4 | Apr 25 | May 9 | Jul 25 | Jul 25 – Sep 5 | 75–100 |
| Rutabaga | — | Apr 25 | — | Jul 25 | Jul 18 – Aug 22 | 80–100 |
| Salsify | — | Apr 25 | — | Jul 25 | Aug 8 – Sep 19 | 100–130 |
| Savoy Cabbage | Apr 4 | Apr 25 | May 9 | Jul 25 | Jul 18 – Sep 12 | 70–110 |
| Scallions | Apr 4 | Apr 25 | May 9 | Jul 25 | 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 25 | 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 25 | 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 25 | 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 25 | 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 25 | Jun 6 – Jul 11 | 40–60 |
| Watercress | Apr 4 | Apr 25 | May 9 | Jul 25 | 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 Yellowstone County
27 fruits that grow well in Zone 5a with planting dates for Yellowstone County.
Show all 27 fruits with planting 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 Yellowstone County
34 herbs that grow well in Zone 5a with planting dates for Yellowstone County.
Show all 34 herbs with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Fall Plant | Harvest | Days to Maturity |
|---|---|---|---|---|---|---|
| Angelica | Apr 4 | Apr 25 | May 2 | Jul 25 | — | 365–730 |
| Anise | Apr 4 | Apr 25 | May 2 | Jul 25 | 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 25 | Jun 27 – Aug 15 | 50–60 |
| Caraway | Apr 4 | Apr 25 | May 2 | Jul 25 | — | 365–450 |
| Catnip | — | — | May 16 | — | Jul 18 – Sep 19 | 60–80 |
| Chamomile | Apr 4 | Apr 25 | May 2 | Jul 25 | Jul 4 – Sep 12 | 60–90 |
| Chervil | Apr 4 | Apr 25 | May 2 | Jul 25 | Jun 13 – Aug 15 | 40–60 |
| Chives | — | — | May 16 | — | Jul 18 – Sep 26 | 60–90 |
| Cilantro | Apr 4 | Apr 25 | May 2 | Jul 25 | Jun 13 – Aug 15 | 40–60 |
| Comfrey | — | — | May 16 | — | Jul 18 – Sep 26 | 60–90 |
| Cumin | Apr 4 | Apr 25 | May 2 | Jul 25 | Aug 15 – Oct 17 | 100–120 |
| Dill | Apr 4 | Apr 25 | May 2 | Jul 25 | 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 25 | 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 25 | 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 25 | 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 Yellowstone County
51 flowers that grow well in Zone 5a with planting dates for Yellowstone County.
Show all 51 flowers with planting 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 22 | Sep 26 – Oct 24 | 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 22 | Jul 4 – Jul 25 | 10–20 |
| Daffodils | — | — | — | Aug 22 | Jul 11 – Aug 1 | 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 22 | Aug 1 – Aug 29 | 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 22 | Jul 25 – Aug 15 | 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 Yellowstone County
Gardening Guides & Resources
Helpful guides from The Ultimate Homestead to improve your garden in Yellowstone County.
Frequently Asked Questions
What planting zone is Yellowstone County, MT?
Yellowstone 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 Yellowstone County, MT?
Based on 31 years of NOAA weather station data, the median last spring frost in Yellowstone County falls around May 9. In 8 out of 10 years, last frost lands between April 24 and May 22 — a 28-day window of variability. Use May 22 as your conservative safe-to-plant date for frost-sensitive crops.
When is the first fall frost in Yellowstone County, MT?
The median first fall frost in Yellowstone County arrives around October 3. In cold years it can arrive as early as September 12; in mild years as late as October 18. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.
How long is the growing season in Yellowstone County?
Yellowstone County has a frost-free growing season of approximately 147 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 2.75 days per decade.
What is the soil like in Yellowstone County for gardening?
Yellowstone County has predominantly Loam soil with a pH range of 6.2–8 and Excessively Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.
What is grown commercially in Yellowstone County?
Yellowstone County has commercial agriculture that includes Cattle, Hay, Wheat. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.
Is Yellowstone County a good location for home gardening?
Yellowstone County scores 30/100 (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.
Your Yellowstone County Garden Planner — Free
A 22-page printable planner built for Yellowstone 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.
The Gardener's Encyclopedia to Companion Planting
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
Seed Saving & Storage Guide
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
Composting Guide for Homesteaders
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