Powder River County, MT — Planting Guide
July in Powder River County, Montana — your action list
July is a pivotal month for Powder River County, Montana gardens. Focus on these tasks first and you'll set up the rest of the season for success.
-
Sow basil, peppers, and pole beans in trays indoors
Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.
-
Basket week: basil, carrots, and cucumber
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
To set up a strong August, finish these tasks
- First harvests: basil, carrots, and cucumber
- Fall sowing: alliums, crocus, and daffodils
Powder River County is in USDA Zone 4b. The average last spring frost is May 15 and the first fall frost is September 22, giving you a growing season of approximately 130 days.
At an elevation of 6,328 ft, Powder River County receives approximately 19.4 in of rainfall annually. Summer highs average 83°F with winter lows around 3°F. The predominant soil type is Loam.
Based on 31 years of NOAA climate station data, the last frost date here varies by 25 days year to year — ranging from May 4 in warm years to May 29 in cold years. The growing season is trending longer by about 3.99 days per decade. Powder River County scores 29/100 (Challenging) on the Microclimate Index.
🌡️ Zone
4b (-25°F to -20°F min)
❄️ Last Frost
May 15
🍂 First Frost
September 22
📅 Growing Season
130 days
⛰️ Elevation
6,328 ft
🌧️ Annual Rainfall
19.4 in
Monthly Watering Calendar for Powder River 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: Watering by the calendar wastes water. Watering by the soil moisture (or by a free rain gauge) cuts your water use 30%+ and produces healthier roots. Powder River County's 19" annual baseline is the starting point.
View detailed monthly data
| Month | Avg Rainfall | Rainy Days | Extra Water Needed | Watering Effort |
|---|---|---|---|---|
| Jan | 1.4 in | 6 days | — | None |
| Feb | 1 in | 6 days | — | None |
| Mar | 1.8 in | 8 days | — | None |
| Apr | 2.2 in | 7 days | 2.1 in | High |
| May | 2.7 in | 7 days | 1.6 in | High |
| Jun | 1.3 in | 5 days | 3 in | High |
| Jul | 1.6 in | 6 days | 2.7 in | High |
| Aug | 1.8 in | 6 days | 2.5 in | High |
| Sep | 1.6 in | 5 days | 2.7 in | High |
| Oct | 1.6 in | 6 days | 2.7 in | High |
| Nov | 1.3 in | 5 days | — | None |
| Dec | 1.3 in | 6 days | — | None |
Annual total: 19.6 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.
Powder River County Soil Profile
Soil Type
Loam
Soil pH
6.5-7.9
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 29 | Oct 6 | 130 days |
| Cautious | May 20 | Oct 1 | 134 days |
| Average year | May 15 | Sep 22 | 130 days |
| Optimistic | May 11 | Sep 19 | 131 days |
| Aggressive (risky) | May 4 | Sep 8 | 127 days |
Not very — frost dates can vary by ±25 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 4 days per decade). Spring is arriving earlier than it used to. Good news for gardeners.
Gardening Difficulty Score
Powder River County has challenging growing conditions. Season extension and careful variety selection are essential.
Local Gardening Help in Powder River 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 Powder River County's climate and soil.
County Extension Office
Powder River 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 Powder River County
Finding local nurseries & garden centers in Powder River County
Why Buy Local
Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Powder River 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 Powder River County MT" or "garden center Powder River 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 Powder River County MT" or check your extension office and local parks department. Facebook groups like "Powder River 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 Powder River County
Monthly daylight hours and peak sun — critical for onion varieties, photoperiod-sensitive plants, and solar garden planning.
For new gardeners: Plants use day length as their seasonal clock. Some crops flower when days lengthen (most flowers), some when days shorten (chrysanthemums, soybeans). Powder River County's curve is the timing layer beneath everything you grow.
Longest Day
15.5 hours
Summer solstice daylight
Shortest Day
8.5 hours
Winter solstice daylight
Peak Sun Hours
11.4 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 | 8.9 hr | 4.9 hr | Short day |
| February | 10.2 hr | 5.9 hr | Short day |
| March | 11.6 hr | 6.6 hr | Short day |
| April | 13.3 hr | 8 hr | Neutral |
| May | 14.7 hr | 9.2 hr | Long day |
| June | 15.5 hr | 11.4 hr | Long day |
| July | 15.1 hr | 10.7 hr | Long day |
| August | 13.9 hr | 9.1 hr | Neutral |
| September | 12.3 hr | 9 hr | Neutral |
| October | 10.7 hr | 6.8 hr | Short day |
| November | 9.3 hr | 5.2 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 Powder River County
Monthly soil temps tell you when to plant warm-season crops, and when your compost pile is actively working.
For new gardeners: Watching soil temperature (not air) is the single biggest upgrade most new gardeners can make. Powder River 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
Jul
Microbial activity peaks when soil is warm.
Active Composting
2 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 | -4°F | 5°F | ❄️ Dormant | ~36 weeks |
| Feb | -4°F | 5°F | ❄️ Dormant | ~36 weeks |
| Mar | 8°F | 11°F | ❄️ Dormant | ~36 weeks |
| Apr | 23°F | 20°F | ❄️ Dormant | ~36 weeks |
| May | 38°F | 31°F | ❄️ Dormant | ~36 weeks |
| Jun | 45°F | 41°F | 🐢 Slow | ~24 weeks |
| Jul | 53°F | 48°F | ♻️ Active | ~14 weeks |
| Aug | 53°F | 49°F | ♻️ Active | ~14 weeks |
| Sep | 46°F | 44°F | 🐢 Slow | ~24 weeks |
| Oct | 33°F | 37°F | ❄️ Dormant | ~36 weeks |
| Nov | 17°F | 24°F | ❄️ Dormant | ~36 weeks |
| Dec | 6°F | 12°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 Powder River County
Computed from local climate patterns — warmer, humid conditions increase pest generations and fungal disease risk.
Why it matters: Pest pressure is a function of climate, not effort. Powder River County's baseline tells you how much vigilance is normal. A bad pest year in low-pressure region = a normal year in high-pressure region.
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 | Moderate | Jun, Jul, Aug |
| Colorado potato beetle | Moderate | Jun, Jul |
| Flea beetles | Moderate | May, Jun, Jul |
| Slugs | Moderate | 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 Powder River County
Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with planting dates calibrated for your area.
For new gardeners: Cover crops are the experienced gardener's secret weapon. Powder River County's climate determines which species thrive: clover and vetch in mild winters, cereal rye and Austrian peas in cold ones.
Spring Cover Crops (2 options) — Build soil before the main growing season
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Buckwheat | May 22 | Jul 28 | — | Rapid growth, attracts pollinators, suppresses weeds |
| White clover | Apr 16 | Jul 28 | ✓ 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 8 | — | 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 8 | Apr 24 | — | Deep taproot breaks compaction, excellent for clay soils |
| Hairy vetch | Jul 15 | Apr 24 | ✓ Yes | Excellent nitrogen fixer, good for depleted soils |
| Oats | Aug 27 | Apr 24 | — | Quick biomass, winterkills in cold zones — no spring tillage needed |
| Winter rye | Jun 24 | Apr 24 | — | Suppresses weeds, prevents erosion, breaks up compacted soil |
| Winter wheat | Jun 17 | Apr 24 | — | Erosion control, weed suppression, good biomass |
Wind & Microclimate in Powder River County
The practical takeaway: Why care about wind? Above about 10 mph, evaporation jumps and pollinators struggle to land on flowers. Powder River County's 10.8 mph average means you can plant tall crops without much support, but it doesn't mean ignore wind — a 20+ mph storm still snaps unstaked tomatoes.
Wind dries soil, stresses plants, and affects frost patterns. Understanding your exposure helps with garden placement.
Seasonal Wind Speed
Spring: 15 mph Summer: 11 mph
Fall: 11 mph Winter: 16 mph
Prevailing wind: W. Windy area — plant a windbreak hedge on the W side of your garden.
Windbreak Benefit
7.1/10
Strongly recommended — a windbreak (fence, hedge, or row of tall crops like corn or sunflowers) will significantly improve garden yields.
Frost Pocket Risk
High
Hilly terrain with 2,268 ft of elevation range — cold air pools in low spots. Avoid planting frost-sensitive crops in valleys.
Rainwater Harvesting in Powder River County
How much water you can collect, when to collect it, and what size system you need for your garden.
What this means for you: A single rain barrel under a downspout catches 50 gallons in a 0.5" storm. Powder River County's 19" annual rainfall means even modest harvesting systems quickly amortize their cost in water savings.
Annual Collection
9,768 gal
Per 1,000 sq ft of roof area (at 80% collection efficiency)
Recommended Setup
8 rain barrels (55 gal each)
For a typical 500 sq ft garden. Serious collectors: consider a 1,750 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
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 19.6 inches of rain per year
- A 1,000 sq ft roof can collect roughly 9,768 gallons annually
- Rainwater harvesting is fully legal in your state
- In your dry climate, every drop counts — consider a larger cistern system
- Position collection tanks in shade to reduce evaporation and algae growth
Soil & Growing Conditions in Powder River County
Soil Type
Loam
Soil pH 6.5–7.9 · Well Drained drainage
Good candidate for raised beds to maximise drainage and extend the season.
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
130-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 Powder River County
95 vegetables that grow well in Zone 4b with planting dates for Powder River County.
Show all 95 vegetables with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Fall Plant | Harvest | Days to Maturity |
|---|---|---|---|---|---|---|
| Acorn Squash | Apr 3 | May 29 | Jun 5 | — | Aug 28 – Oct 2 | 80–100 |
| Amaranth | Mar 13 | May 29 | Jun 5 | — | Sep 4 – Oct 23 | 90–120 |
| Arugula | Apr 3 | May 8 | May 15 | Jun 30 | Jun 19 – Aug 21 | 30–50 |
| Asparagus | — | — | May 29 | — | — | 730–1095 |
| Beets | — | May 8 | — | Jun 30 | Jul 3 – Jul 31 | 50–70 |
| Belgian Endive | Apr 3 | May 8 | May 15 | Jun 30 | Sep 4 – Oct 9 | 110–150 |
| Black Beans | — | May 29 | — | — | Aug 28 – Oct 16 | 90–120 |
| Bok Choy | Apr 3 | May 8 | May 15 | Jun 30 | Jun 26 – Jul 31 | 40–60 |
| Broccoli | Apr 3 | May 8 | May 15 | Jun 30 | Jul 17 – Aug 28 | 60–90 |
| Broccoli Rabe | Apr 3 | May 8 | May 15 | Jun 30 | Jun 26 – Jul 31 | 40–60 |
| Brussels Sprouts | Apr 3 | May 8 | May 15 | Jun 30 | Aug 14 – Oct 9 | 90–130 |
| Butternut Squash | Apr 3 | May 29 | Jun 5 | — | Sep 4 – Oct 9 | 85–110 |
| Cabbage | Apr 3 | May 8 | May 15 | Jun 30 | Jul 17 – Sep 11 | 60–100 |
| Carrots | — | May 8 | — | Jun 30 | Jul 10 – Aug 14 | 60–80 |
| Cauliflower | Apr 3 | May 8 | May 15 | Jun 30 | Jul 10 – Sep 11 | 55–100 |
| Celeriac | Apr 3 | May 8 | May 15 | Jun 30 | Aug 28 – Oct 2 | 100–120 |
| Celery | Apr 3 | May 8 | May 15 | Jun 30 | Aug 7 – Oct 2 | 80–120 |
| Celtuce | Apr 3 | May 8 | May 15 | Jun 30 | Jul 17 – Aug 28 | 60–90 |
| Chard | Apr 3 | May 8 | May 15 | Jun 30 | Jul 10 – Aug 28 | 50–60 |
| Chickpeas | Apr 3 | May 8 | May 15 | Jun 30 | Aug 7 – Sep 18 | 80–110 |
| Chicory | Apr 3 | May 8 | May 15 | Jun 30 | Jul 17 – Aug 28 | 60–85 |
| Chinese Cabbage | Apr 3 | May 8 | May 15 | Jun 30 | Jul 10 – Aug 7 | 50–70 |
| Christmas Lima Beans | Mar 13 | May 29 | Jun 5 | — | Aug 28 – Oct 2 | 80–100 |
| Collard Greens | Apr 3 | May 8 | May 15 | Jun 30 | Jul 10 – Sep 11 | 55–75 |
| Corn | — | May 29 | — | — | Jul 31 – Sep 25 | 60–100 |
| Cress | Apr 3 | May 8 | May 15 | Jun 30 | May 29 – Jun 19 | 14–21 |
| Crookneck Squash | Apr 3 | May 29 | Jun 5 | — | Jul 24 – Aug 21 | 45–60 |
| Crosne | — | May 8 | — | Jun 30 | Oct 9 – Oct 2 | 150–200 |
| Cucumber | Apr 3 | May 29 | Jun 5 | — | Jul 31 – Sep 25 | 50–70 |
| Daikon | — | May 8 | — | Jun 30 | Jul 3 – Jul 31 | 50–70 |
| Delicata Squash | Apr 3 | May 29 | Jun 5 | — | Aug 28 – Oct 2 | 80–100 |
| Edamame | — | May 29 | — | — | Aug 14 – Sep 25 | 75–100 |
| Endive | Apr 3 | May 8 | May 15 | Jun 30 | Jul 3 – Aug 7 | 45–65 |
| Escarole | Apr 3 | May 8 | May 15 | Jun 30 | Jul 10 – Aug 7 | 50–70 |
| Fava Beans | Apr 3 | May 8 | May 15 | Jun 30 | Jul 31 – Sep 11 | 75–100 |
| Fennel | Mar 13 | May 29 | Jun 5 | — | Aug 7 – Sep 18 | 60–90 |
| Garlic | — | — | — | Aug 11 | Nov 10 – Jan 5 | 90–240 |
| Green Beans | — | May 29 | — | — | Jul 24 – Sep 18 | 50–65 |
| Horseradish | — | — | May 29 | — | Oct 2 – Oct 23 | 120–180 |
| Hubbard Squash | Apr 3 | May 29 | Jun 5 | — | Sep 18 – Oct 23 | 100–120 |
| Kabocha | Apr 3 | May 29 | Jun 5 | — | Sep 4 – Oct 2 | 85–100 |
| Kai Lan | Apr 3 | May 8 | May 15 | Jun 30 | Jul 3 – Jul 31 | 45–60 |
| Kale | Apr 3 | May 8 | May 15 | Jun 30 | Jul 10 – Sep 4 | 50–70 |
| Kidney Beans | — | May 29 | — | — | Aug 28 – Oct 2 | 85–110 |
| Kohlrabi | Apr 3 | May 8 | May 15 | Jun 30 | Jul 3 – Aug 7 | 45–65 |
| Komatsuna | Apr 3 | May 8 | May 15 | Jun 30 | Jun 19 – Jul 24 | 35–50 |
| Leeks | Apr 3 | May 8 | May 15 | Jun 30 | Aug 14 – Oct 9 | 90–150 |
| Lentils | Apr 3 | May 8 | May 15 | Jun 30 | Aug 7 – Sep 18 | 80–110 |
| Lettuce | Apr 3 | May 8 | May 15 | Jun 30 | Jun 19 – Aug 28 | 30–60 |
| Lima Beans | — | May 29 | — | — | Jul 31 – Sep 11 | 60–90 |
| Mache | Apr 3 | May 8 | May 15 | Jun 30 | Jun 26 – Jul 31 | 40–60 |
| Melon | Apr 3 | May 29 | Jun 5 | — | Aug 14 – Oct 2 | 70–100 |
| Microgreens | Apr 3 | May 8 | May 15 | Jun 30 | May 22 – Jun 19 | 7–21 |
| Mitsuba | Apr 3 | May 8 | May 8 | Jun 30 | Jul 3 – Aug 28 | 50–70 |
| Mizuna | Apr 3 | May 8 | May 15 | Jun 30 | Jun 19 – Jul 17 | 30–45 |
| Mustard Greens | Apr 3 | May 8 | May 15 | Jun 30 | Jun 19 – Aug 21 | 30–50 |
| Napa Cabbage | Apr 3 | May 8 | May 15 | Jun 30 | Jul 10 – Aug 14 | 55–75 |
| Onion | Apr 3 | May 8 | May 15 | Jun 30 | Aug 14 – Oct 2 | 90–120 |
| Pac Choi | Apr 3 | May 8 | May 15 | Jun 30 | Jun 26 – Jul 24 | 40–55 |
| Parsnip | — | May 8 | — | Jun 30 | Aug 21 – Oct 2 | 100–130 |
| Patty Pan Squash | Apr 3 | May 29 | Jun 5 | — | Jul 24 – Aug 21 | 45–60 |
| Peas | Apr 3 | May 8 | May 15 | Jun 30 | Jul 10 – Sep 4 | 55–70 |
| Peppers | Feb 27 | May 29 | Jun 5 | — | Aug 7 – Oct 16 | 60–90 |
| Pole Beans | Mar 13 | May 29 | Jun 5 | — | Jul 31 – Sep 25 | 55–70 |
| Potatoes | Mar 13 | May 29 | Jun 5 | — | Aug 14 – Oct 23 | 70–120 |
| Pumpkin | Apr 3 | May 29 | Jun 5 | — | Sep 4 – Oct 23 | 85–120 |
| Purslane | Apr 3 | May 8 | May 15 | Jun 30 | Jun 26 – Jul 31 | 40–60 |
| Radicchio | Apr 3 | May 8 | May 15 | Jun 30 | Jul 17 – Aug 21 | 60–80 |
| Radish | — | May 8 | — | Jun 30 | Jun 5 – Jun 26 | 22–35 |
| Rhubarb | — | — | Jun 12 | — | — | 365–730 |
| Romanesco | Apr 3 | May 8 | May 15 | Jun 30 | Jul 31 – Sep 11 | 75–100 |
| Rutabaga | — | May 8 | — | Jun 30 | Jul 31 – Sep 4 | 80–100 |
| Salsify | — | May 8 | — | Jun 30 | Aug 21 – Oct 2 | 100–130 |
| Savoy Cabbage | Apr 3 | May 8 | May 15 | Jun 30 | Jul 24 – Sep 18 | 70–110 |
| Scallions | Apr 3 | May 8 | May 15 | Jun 30 | Jul 10 – Aug 7 | 50–70 |
| Scarlet Runner Beans | Mar 13 | May 29 | Jun 5 | — | Aug 7 – Sep 11 | 60–80 |
| Shallot | Apr 3 | May 8 | May 15 | Jun 30 | Aug 14 – Oct 2 | 90–120 |
| Shiso | Mar 20 | May 22 | Jun 5 | — | Jul 31 – Sep 25 | 50–70 |
| Snap Peas | Mar 13 | May 29 | Jun 5 | — | Jul 31 – Sep 25 | 55–70 |
| Snow Peas | Apr 3 | May 8 | May 15 | Jun 30 | Jul 10 – Sep 4 | 50–65 |
| Soybeans | — | May 29 | — | — | Aug 21 – Oct 16 | 80–120 |
| Spaghetti Squash | Apr 3 | May 29 | Jun 5 | — | Sep 4 – Oct 2 | 85–100 |
| Spinach | Apr 3 | May 8 | May 15 | Jun 30 | Jun 19 – Aug 21 | 35–50 |
| Squash (Summer) | Apr 3 | May 29 | Jun 5 | — | Jul 24 – Sep 25 | 45–65 |
| Squash (Winter) | Apr 3 | May 29 | Jun 5 | — | Aug 28 – Oct 23 | 80–120 |
| Sunchoke | — | — | May 29 | — | Sep 18 – Oct 23 | 110–150 |
| Sweet Corn | — | May 29 | — | — | Jul 31 – Sep 11 | 60–90 |
| Tatsoi | Apr 3 | May 8 | May 15 | Jun 30 | Jun 19 – Jul 24 | 35–50 |
| Tomatillo | Mar 13 | May 29 | Jun 5 | — | Aug 7 – Oct 16 | 60–85 |
| Tomatoes | Mar 13 | May 29 | Jun 5 | — | Aug 7 – Oct 16 | 60–85 |
| Turnip | — | May 8 | — | Jun 30 | Jun 19 – Jul 24 | 40–60 |
| Watercress | Apr 3 | May 8 | May 15 | Jun 30 | Jun 26 – Jul 31 | 40–60 |
| Watermelon | Apr 3 | May 29 | Jun 5 | — | Aug 14 – Oct 2 | 70–100 |
| Wax Beans | — | May 29 | — | — | Jul 24 – Sep 18 | 50–65 |
| Zucchini | Apr 3 | May 29 | Jun 5 | — | Jul 24 – Sep 18 | 45–60 |
🍓 Fruits to Grow in Powder River County
22 fruits that grow well in Zone 4b with planting dates for Powder River County.
Show all 22 fruits with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Fall Plant | Harvest | Days to Maturity |
|---|---|---|---|---|---|---|
| Alpine Strawberries | — | — | Jun 12 | — | Sep 11 – Nov 6 | 90–180 |
| Aronia | — | — | Jun 12 | — | — | 730–1095 |
| Blueberries | — | — | Jun 12 | — | — | 730–1095 |
| Cantaloupe | — | — | Jun 12 | — | Aug 21 – Sep 25 | 70–90 |
| Cranberries | — | — | Jun 12 | — | — | 730–1095 |
| Currants | — | — | Jun 12 | — | — | 730–1095 |
| Elderberries | — | — | Jun 12 | — | — | 730–1095 |
| Goji Berries | — | — | Jun 12 | — | — | 730–1095 |
| Gooseberries | — | — | Jun 12 | — | — | 730–1095 |
| Grapes | — | — | Jun 12 | — | — | 730–1095 |
| Ground Cherry | — | — | Jun 12 | — | Aug 21 – Oct 16 | 65–80 |
| Hardy Kiwi | — | — | Jun 12 | — | — | 1095–1825 |
| Haskaps | — | — | Jun 12 | — | — | 730–1095 |
| Honeydew | — | — | Jun 12 | — | Sep 4 – Oct 16 | 80–110 |
| Jostaberry | — | — | Jun 12 | — | — | 730–1095 |
| Lingonberries | — | — | Jun 12 | — | — | 730–1095 |
| Medlar | — | — | Jun 12 | — | — | 1095–1825 |
| Mulberries | — | — | Jun 12 | — | — | 730–1825 |
| Persimmon | — | — | Jun 12 | — | — | 1095–2555 |
| Raspberries | — | — | Jun 12 | — | — | 365–730 |
| Serviceberries | — | — | Jun 12 | — | — | 730–1095 |
| Strawberries | — | — | Jun 12 | — | Sep 11 – Nov 6 | 90–365 |
🌿 Herbs to Grow in Powder River County
30 herbs that grow well in Zone 4b with planting dates for Powder River County.
Show all 30 herbs with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Fall Plant | Harvest | Days to Maturity |
|---|---|---|---|---|---|---|
| Angelica | Apr 3 | May 8 | May 8 | Jun 30 | — | 365–730 |
| Anise | Apr 3 | May 8 | May 8 | Jun 30 | Aug 7 – Oct 2 | 90–120 |
| Basil | Mar 20 | May 22 | Jun 5 | — | Jul 31 – Oct 2 | 50–75 |
| Bee Balm | — | — | May 22 | — | Aug 21 – Oct 16 | 90–120 |
| Borage | Apr 3 | May 8 | May 8 | Jun 30 | Jul 3 – Aug 21 | 50–60 |
| Caraway | Apr 3 | May 8 | May 8 | Jun 30 | — | 365–450 |
| Catnip | — | — | May 22 | — | Jul 24 – Sep 25 | 60–80 |
| Chamomile | Apr 3 | May 8 | May 8 | Jun 30 | Jul 10 – Sep 18 | 60–90 |
| Chervil | Apr 3 | May 8 | May 8 | Jun 30 | Jun 19 – Aug 21 | 40–60 |
| Chives | — | — | May 22 | — | Jul 24 – Oct 2 | 60–90 |
| Cilantro | Apr 3 | May 8 | May 8 | Jun 30 | Jun 19 – Aug 21 | 40–60 |
| Comfrey | — | — | May 22 | — | Jul 24 – Oct 2 | 60–90 |
| Dill | Apr 3 | May 8 | May 8 | Jun 30 | Jun 19 – Aug 21 | 40–60 |
| Fennel (herb) | Apr 3 | May 8 | May 8 | Jun 30 | Jul 10 – Sep 18 | 60–90 |
| Garlic Chives | — | — | May 22 | — | Jul 24 – Oct 2 | 60–90 |
| Horehound | — | — | May 22 | — | Aug 7 – Oct 2 | 75–90 |
| Hyssop | — | — | May 22 | — | Jul 31 – Oct 2 | 70–90 |
| Lemon Balm | — | — | May 22 | — | Jul 24 – Sep 11 | 60–70 |
| Lovage | — | — | May 22 | — | Jul 31 – Oct 2 | 70–90 |
| Mint | — | — | May 22 | — | Jul 24 – Oct 2 | 60–90 |
| Oregano | — | — | May 22 | — | Jul 24 – Oct 2 | 60–90 |
| Parsley | Apr 3 | May 8 | May 8 | Jun 30 | Jul 10 – Sep 11 | 60–80 |
| Rue | — | — | May 22 | — | Jul 31 – Oct 2 | 70–90 |
| Sage | — | — | May 22 | — | Aug 7 – Oct 2 | 75–90 |
| Savory | — | — | May 22 | — | Jul 17 – Sep 11 | 50–70 |
| Sorrel | Apr 3 | May 8 | May 8 | Jun 30 | Jun 19 – Aug 21 | 40–60 |
| Tarragon | — | — | May 22 | — | Jul 24 – Oct 2 | 60–90 |
| Thai Basil | Mar 20 | May 22 | Jun 5 | — | Jul 31 – Oct 2 | 50–75 |
| Thyme | — | — | May 22 | — | Jul 31 – Oct 2 | 70–90 |
| Valerian | — | — | May 22 | — | Sep 25 – Oct 16 | 120–180 |
🌸 Flowers to Grow in Powder River County
49 flowers that grow well in Zone 4b with planting dates for Powder River County.
Show all 49 flowers with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Fall Plant | Bloom | Days to Maturity |
|---|---|---|---|---|---|---|
| Ageratum | Mar 27 | May 22 | May 22 | — | Jul 17 – Oct 2 | 60–75 |
| Alliums | — | — | — | Aug 11 | Sep 15 – Oct 13 | 28–42 |
| Astilbe | Mar 6 | — | May 29 | — | Aug 21 – Oct 16 | 70–100 |
| Bachelor's Button | Mar 27 | May 1 | May 15 | — | Jul 17 – Sep 18 | 60–90 |
| Begonias | Feb 27 | — | May 22 | — | Jul 31 – Oct 9 | 70–90 |
| Black-eyed Susan | Mar 6 | May 15 | May 29 | — | Aug 21 – Nov 6 | 60–80 |
| Bleeding Hearts | Mar 6 | — | May 29 | — | Jul 24 – Sep 4 | 60–90 |
| Calendula | Mar 27 | May 1 | May 15 | — | Jul 3 – Sep 18 | 50–70 |
| Celosia | Apr 10 | May 29 | May 29 | — | Jul 31 – Oct 16 | 60–90 |
| Columbine | Mar 6 | May 29 | May 29 | — | Jul 24 – Sep 11 | 70–100 |
| Coreopsis | Mar 6 | May 22 | May 29 | — | Aug 14 – Nov 6 | 60–80 |
| Cosmos | Apr 17 | May 22 | May 22 | — | Jul 31 – Oct 23 | 60–90 |
| Crocus | — | — | — | Aug 11 | Jun 16 – Jul 14 | 10–20 |
| Daffodils | — | — | — | Aug 11 | Jun 23 – Jul 21 | 20–40 |
| Dahlias | Apr 17 | May 29 | May 29 | — | Aug 28 – Nov 6 | 70–120 |
| Daylily | Mar 6 | — | May 29 | — | Aug 28 – Nov 6 | 60–90 |
| Dianthus | Mar 13 | Apr 24 | May 8 | — | Jun 26 – Sep 4 | 60–80 |
| Echinacea (Purple Coneflower) | Mar 6 | May 29 | May 29 | — | Aug 28 – Nov 6 | 70–90 |
| Foxglove | Mar 6 | May 29 | May 29 | — | Jul 24 – Sep 4 | 80–120 |
| Gaillardia (Blanket Flower) | Mar 20 | May 29 | May 29 | — | Aug 7 – Nov 13 | 70–100 |
| Geraniums | Feb 27 | — | May 22 | — | Jul 31 – Oct 9 | 70–100 |
| Gladiolus | — | May 22 | May 22 | — | Aug 21 – Oct 30 | 70–100 |
| Hostas | Feb 27 | — | May 29 | — | Aug 28 – Nov 6 | 60–90 |
| Hyacinths | — | — | — | Aug 11 | Jul 14 – Aug 4 | 14–28 |
| Hydrangeas | Feb 27 | — | May 29 | — | Aug 21 – Oct 23 | 90–150 |
| Impatiens | Mar 13 | — | May 29 | — | Aug 14 – Oct 16 | 60–75 |
| Irises | — | Division | May 29 | — | Jul 24 – Aug 28 | 60–100 |
| Larkspur | — | Apr 17 | — | — | Jun 26 – Aug 14 | 60–90 |
| Lilies | — | Division | May 29 | — | Aug 21 – Oct 23 | 70–120 |
| Lobelia | Mar 6 | — | May 15 | — | Jul 10 – Sep 11 | 70–80 |
| Lupine | Mar 6 | May 29 | May 29 | — | Jul 24 – Sep 4 | 75–100 |
| Marigolds | Apr 3 | May 22 | May 22 | — | Jul 17 – Oct 2 | 50–70 |
| Nasturtium | Apr 17 | May 22 | May 22 | — | Jul 17 – Oct 9 | 55–65 |
| Pansy | Feb 27 | — | May 15 | — | Jul 10 – Aug 28 | 70–90 |
| Peonies | — | Division | May 29 | — | Aug 7 – Sep 11 | 90–120 |
| Petunia | Mar 13 | — | May 22 | — | Jul 31 – Oct 16 | 70–90 |
| Phlox | Mar 6 | May 29 | May 29 | — | Aug 21 – Oct 30 | 80–110 |
| Portulaca | Apr 10 | May 29 | May 29 | — | Jul 17 – Oct 2 | 50–70 |
| Roses | Feb 27 | — | May 29 | — | Aug 21 – Nov 6 | 90–180 |
| Salvia | Mar 13 | — | May 22 | — | Jul 31 – Oct 9 | 70–90 |
| Sedum (Stonecrop) | Mar 6 | — | May 29 | — | Oct 2 – Nov 27 | 60–90 |
| Snapdragon | Mar 6 | — | May 15 | — | Jul 24 – Sep 18 | 70–100 |
| Sunflower | Apr 24 | May 22 | May 22 | — | Aug 14 – Oct 16 | 70–100 |
| Sweet Alyssum | Mar 27 | May 8 | May 15 | — | Jun 26 – Aug 28 | 45–60 |
| Sweet Pea | Apr 3 | Apr 10 | May 15 | — | Aug 7 – Sep 25 | 65–85 |
| Tulips | — | — | — | Aug 11 | Jul 7 – Jul 28 | 15–30 |
| Vinca (Annual) | Feb 27 | — | May 29 | — | Aug 7 – Oct 16 | 70–90 |
| Yarrow | Mar 6 | May 15 | May 29 | — | Aug 14 – Nov 6 | 60–90 |
| Zinnia | Apr 17 | May 22 | May 22 | — | Jul 31 – Oct 16 | 60–70 |
Monthly Planting Guide for Powder River County
Gardening Guides & Resources
Helpful guides from The Ultimate Homestead to improve your garden in Powder River County.
Frequently Asked Questions
What planting zone is Powder River County, MT?
Powder River County is in USDA Hardiness Zone 4b. 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 Powder River County, MT?
Based on 31 years of NOAA weather station data, the median last spring frost in Powder River County falls around May 15. In 8 out of 10 years, last frost lands between May 4 and May 29 — a 25-day window of variability. Use May 29 as your conservative safe-to-plant date for frost-sensitive crops.
When is the first fall frost in Powder River County, MT?
The median first fall frost in Powder River County arrives around September 22. In cold years it can arrive as early as September 8; in mild years as late as October 6. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.
How long is the growing season in Powder River County?
Powder River County has a frost-free growing season of approximately 130 days. Focus on short-season varieties and start warm-season crops indoors 6–8 weeks before last frost. Climate records show the growing season is trending longer by about 3.99 days per decade.
What is the soil like in Powder River County for gardening?
Powder River County has predominantly Loam soil with a pH range of 6.5–7.9 and Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.
What is grown commercially in Powder River County?
Powder River County has commercial agriculture that includes Cattle, Wheat, Hay, Sugar Beets, Barley. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.
Is Powder River County a good location for home gardening?
Powder River County scores 29/100 (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 Powder River County Garden Planner — Free
A 22-page printable planner built for Powder River County (Zone 4b). 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