Lemhi County, ID — Planting Guide
Lemhi County is in USDA Zone 4b. The average last spring frost is June 9 and the first fall frost is September 14, giving you a growing season of approximately 97 days.
At an elevation of 6,743 ft, Lemhi County receives approximately 12.6 in of rainfall annually. Summer highs average 84°F with winter lows around 1°F. The predominant soil type is Loam.
Based on 31 years of NOAA climate station data, the last frost date here varies by 51 days year to year — ranging from May 5 in warm years to June 25 in cold years. The growing season is trending longer by about 0.54 days per decade. Lemhi County scores 41/100 (Moderate) on the Microclimate Index.
🌡️ Zone
4b (-25°F to -20°F min)
❄️ Last Frost
June 9
🍂 First Frost
September 14
📅 Growing Season
97 days
⛰️ Elevation
6,743 ft
🌧️ Annual Rainfall
12.6 in
Monthly Watering Calendar
When you'll need to water your garden — based on average monthly rainfall vs. the ~1 inch/week most gardens need.
View detailed monthly data
| Month | Avg Rainfall | Rainy Days | Extra Water Needed | Watering Effort |
|---|---|---|---|---|
| Jan | 0.8 in | 7 days | — | None |
| Feb | 0.9 in | 6 days | — | None |
| Mar | 1 in | 7 days | — | None |
| Apr | 1.3 in | 6 days | 3 in | High |
| May | 1.4 in | 8 days | 2.9 in | High |
| Jun | 0.8 in | 5 days | 3.5 in | Critical |
| Jul | 1.3 in | 6 days | 3 in | High |
| Aug | 1.3 in | 7 days | 3 in | High |
| Sep | 1.2 in | 6 days | 3.1 in | Critical |
| Oct | 1 in | 6 days | 3.3 in | Critical |
| Nov | 1 in | 6 days | — | None |
| Dec | 0.8 in | 7 days | — | None |
Annual total: 12.8 in. Gardens typically need ~1 inch of water per week during the growing season. Months marked "None" for extra water are outside the active growing season for your zone — most gardens are dormant and don't need irrigation during those months.
Lemhi County Soil Profile
Soil Type
Loam
Soil pH
6.2-8.2
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) | Jun 25 | Oct 6 | 103 days |
| Cautious | Jun 19 | Sep 25 | 98 days |
| Average year | Jun 9 | Sep 14 | 97 days |
| Optimistic | May 14 | Aug 30 | 108 days |
| Aggressive (risky) | May 5 | Aug 15 | 102 days |
Not very — frost dates can vary by ±51 days year-to-year. Use the "Conservative" row in the table below, and keep row covers handy for surprise late frosts.
Slightly — seasons are trending a bit longer (0.5 days/decade). Historical frost dates are still reliable for planning.
Gardening Difficulty Score
Lemhi County presents some gardening challenges. Choose adapted varieties and plan around frost dates.
Local Gardening Help in Lemhi 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 Lemhi County's climate and soil.
County Extension Office
Lemhi County University of Idaho Extension Extension Office
Phone: 208-885-6681
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 Lemhi County
Finding local nurseries & garden centers in Lemhi County
Why Buy Local
Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Lemhi 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 Lemhi County ID" or "garden center Lemhi 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 Lemhi County ID" or check your extension office and local parks department. Facebook groups like "Lemhi County Gardeners" or "Idaho Gardening" are also excellent for local advice and plant swaps.
What to Plant After Your Harvest
After your first crops finish, use the remaining frost-free days to grow a second round.
Sunlight & Day Length
Monthly daylight hours and peak sun — critical for onion varieties, photoperiod-sensitive plants, and solar garden planning.
Longest Day
15.4 hours
Summer solstice daylight
Shortest Day
8.6 hours
Winter solstice daylight
Peak Sun Hours
10.7 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 | 9 hr | 4.7 hr | Short day |
| February | 10.2 hr | 6 hr | Short day |
| March | 11.6 hr | 7.3 hr | Short day |
| April | 13.3 hr | 8 hr | Neutral |
| May | 14.6 hr | 8.8 hr | Long day |
| June | 15.4 hr | 10.7 hr | Long day |
| July | 15.1 hr | 10.4 hr | Long day |
| August | 13.9 hr | 9 hr | Neutral |
| September | 12.3 hr | 8.3 hr | Neutral |
| October | 10.7 hr | 7.2 hr | Short day |
| November | 9.3 hr | 5.2 hr | Short day |
| December | 8.6 hr | 4.9 hr | Short day |
Peak sun hours factor in typical cloud cover — use these for solar panel and shade-planning calculations.
Soil Temperature & Composting Calendar
Monthly soil temps tell you when to plant warm-season crops, and when your compost pile is actively working.
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 | -8°F | 4°F | ❄️ Dormant | ~36 weeks |
| Feb | -2°F | 4°F | ❄️ Dormant | ~36 weeks |
| Mar | 5°F | 8°F | ❄️ Dormant | ~36 weeks |
| Apr | 20°F | 18°F | ❄️ Dormant | ~36 weeks |
| May | 33°F | 32°F | ❄️ Dormant | ~36 weeks |
| Jun | 43°F | 40°F | 🐢 Slow | ~24 weeks |
| Jul | 54°F | 46°F | ♻️ Active | ~14 weeks |
| Aug | 53°F | 49°F | ♻️ Active | ~14 weeks |
| Sep | 47°F | 45°F | 🐢 Slow | ~24 weeks |
| Oct | 31°F | 35°F | ❄️ Dormant | ~36 weeks |
| Nov | 18°F | 24°F | ❄️ Dormant | ~36 weeks |
| Dec | 2°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 Lemhi County
Computed from local climate patterns — warmer, humid conditions increase pest generations and fungal disease risk.
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 | Low | 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 Lemhi County
Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with county-specific planting dates.
Fall Cover Crops (5 options) — Plant after harvest to protect soil over winter
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Daikon radish | Aug 2 | May 26 | — | Deep taproot breaks compaction, excellent for clay soils |
| Hairy vetch | Jun 24 | May 26 | ✓ Yes | Excellent nitrogen fixer, good for depleted soils |
| Oats | Aug 16 | May 26 | — | Quick biomass, winterkills in cold zones — no spring tillage needed |
| Winter rye | Jun 5 | May 19 | — | Suppresses weeds, prevents erosion, breaks up compacted soil |
| Winter wheat | Jun 23 | May 26 | — | Erosion control, weed suppression, good biomass |
Spring Cover Crops (2 options) — Build soil before the main growing season
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Buckwheat | Jun 15 | Jul 13 | — | Rapid growth, attracts pollinators, suppresses weeds |
| White clover | May 15 | Jul 6 | ✓ 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 | Jul 8 | Aug 31 | — | Deep roots break compaction, attract pollinators and beneficial insects |
Wind & Microclimate
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: 14 mph Winter: 16 mph
Prevailing wind: W. Windy area — plant a windbreak hedge on the W side of your garden.
Windbreak Benefit
6.7/10
Moderately beneficial — a simple fence or trellis can protect delicate crops from wind stress.
Frost Pocket Risk
High
Hilly terrain with 1,125 ft of elevation range — cold air pools in low spots. Avoid planting frost-sensitive crops in valleys.
Rainwater Harvesting Potential
How much water you can collect, when to collect it, and what size system you need for your garden.
Annual Collection
6,379 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, 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 12.8 inches of rain per year
- A 1,000 sq ft roof can collect roughly 6,379 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 Lemhi County
Soil Type
Loam
Soil pH 6.2–8.2 · Well Drained drainage
Good candidate for raised beds to maximise drainage and extend the season.
Watering Needs
Drought stress: 5.5/10
Moderate drought pressure. Drip irrigation and mulching are highly recommended to maintain soil moisture through summer.
Season Tips
97-day frost-free season
A short season means indoor starts are critical for warm-season crops. Prioritise cold-hardy, fast-maturing varieties and use row covers to extend autumn harvests.
Free Garden Planner
Plan your entire garden season — organize planting dates, track what you're growing, and know exactly when to start seeds, transplant, and harvest.
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 Lemhi County
96 vegetables that grow well in Zone 4b with planting dates for Lemhi County.
Show all 96 vegetables with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Acorn Squash | Apr 28 | Jun 23 | Jun 30 | Sep 22 – Oct 27 | 80–100 |
| Amaranth | Apr 7 | Jun 23 | Jun 30 | Sep 29 – Nov 17 | 90–120 |
| Arugula | Apr 28 | Jun 2 | Jun 9 | Jul 14 – Sep 15 | 30–50 |
| Asparagus | — | — | Jun 23 | — | 730–1095 |
| Beets | — | Jun 2 | — | Jul 28 – Aug 25 | 50–70 |
| Belgian Endive | Apr 28 | Jun 2 | Jun 9 | Sep 29 – Nov 3 | 110–150 |
| Black Beans | — | Jun 23 | — | Sep 22 – Nov 10 | 90–120 |
| Bok Choy | Apr 28 | Jun 2 | Jun 9 | Jul 21 – Aug 25 | 40–60 |
| Broccoli | Apr 28 | Jun 2 | Jun 9 | Aug 11 – Sep 22 | 60–90 |
| Broccoli Rabe | Apr 28 | Jun 2 | Jun 9 | Jul 21 – Aug 25 | 40–60 |
| Brussels Sprouts | Apr 28 | Jun 2 | Jun 9 | Sep 8 – Nov 3 | 90–130 |
| Butternut Squash | Apr 28 | Jun 23 | Jun 30 | Sep 29 – Nov 3 | 85–110 |
| Cabbage | Apr 28 | Jun 2 | Jun 9 | Aug 11 – Oct 6 | 60–100 |
| Carrots | — | Jun 2 | — | Aug 4 – Sep 8 | 60–80 |
| Cauliflower | Apr 28 | Jun 2 | Jun 9 | Aug 4 – Oct 6 | 55–100 |
| Celeriac | Apr 28 | Jun 2 | Jun 9 | Sep 22 – Oct 27 | 100–120 |
| Celery | Apr 28 | Jun 2 | Jun 9 | Sep 1 – Oct 27 | 80–120 |
| Celtuce | Apr 28 | Jun 2 | Jun 9 | Aug 11 – Sep 22 | 60–90 |
| Chard | Apr 28 | Jun 2 | Jun 9 | Aug 4 – Sep 22 | 50–60 |
| Chickpeas | Apr 28 | Jun 2 | Jun 9 | Sep 1 – Oct 13 | 80–110 |
| Chicory | Apr 28 | Jun 2 | Jun 9 | Aug 11 – Sep 22 | 60–85 |
| Chinese Cabbage | Apr 28 | Jun 2 | Jun 9 | Aug 4 – Sep 1 | 50–70 |
| Christmas Lima Beans | Apr 7 | Jun 23 | Jun 30 | Sep 22 – Oct 27 | 80–100 |
| Collard Greens | Apr 28 | Jun 2 | Jun 9 | Aug 4 – Oct 6 | 55–75 |
| Corn | — | Jun 23 | — | Aug 25 – Oct 20 | 60–100 |
| Cress | Apr 28 | Jun 2 | Jun 9 | Jun 23 – Jul 14 | 14–21 |
| Crookneck Squash | Apr 28 | Jun 23 | Jun 30 | Aug 18 – Sep 15 | 45–60 |
| Crosne | — | Jun 2 | — | Nov 3 – Oct 27 | 150–200 |
| Cucumber | Apr 28 | Jun 23 | Jun 30 | Aug 25 – Oct 20 | 50–70 |
| Daikon | — | Jun 2 | — | Jul 28 – Aug 25 | 50–70 |
| Delicata Squash | Apr 28 | Jun 23 | Jun 30 | Sep 22 – Oct 27 | 80–100 |
| Edamame | — | Jun 23 | — | Sep 8 – Oct 20 | 75–100 |
| Endive | Apr 28 | Jun 2 | Jun 9 | Jul 28 – Sep 1 | 45–65 |
| Escarole | Apr 28 | Jun 2 | Jun 9 | Aug 4 – Sep 1 | 50–70 |
| Fava Beans | Apr 28 | Jun 2 | Jun 9 | Aug 25 – Oct 6 | 75–100 |
| Fennel | Apr 7 | Jun 23 | Jun 30 | Sep 1 – Oct 13 | 60–90 |
| Garlic | — | — | — | — | 90–240 |
| Green Beans | — | Jun 23 | — | Aug 18 – Oct 13 | 50–65 |
| Horseradish | — | — | Jun 23 | Oct 27 – Nov 17 | 120–180 |
| Hubbard Squash | Apr 28 | Jun 23 | Jun 30 | Oct 13 – Nov 17 | 100–120 |
| Kabocha | Apr 28 | Jun 23 | Jun 30 | Sep 29 – Oct 27 | 85–100 |
| Kai Lan | Apr 28 | Jun 2 | Jun 9 | Jul 28 – Aug 25 | 45–60 |
| Kale | Apr 28 | Jun 2 | Jun 9 | Aug 4 – Sep 29 | 50–70 |
| Kidney Beans | — | Jun 23 | — | Sep 22 – Oct 27 | 85–110 |
| Kohlrabi | Apr 28 | Jun 2 | Jun 9 | Jul 28 – Sep 1 | 45–65 |
| Komatsuna | Apr 28 | Jun 2 | Jun 9 | Jul 14 – Aug 18 | 35–50 |
| Leeks | Apr 28 | Jun 2 | Jun 9 | Sep 8 – Nov 3 | 90–150 |
| Lentils | Apr 28 | Jun 2 | Jun 9 | Sep 1 – Oct 13 | 80–110 |
| Lettuce | Apr 28 | Jun 2 | Jun 9 | Jul 14 – Sep 22 | 30–60 |
| Lima Beans | — | Jun 23 | — | Aug 25 – Oct 6 | 60–90 |
| Mache | Apr 28 | Jun 2 | Jun 9 | Jul 21 – Aug 25 | 40–60 |
| Melon | Apr 28 | Jun 23 | Jun 30 | Sep 8 – Oct 27 | 70–100 |
| Microgreens | Apr 28 | Jun 2 | Jun 9 | Jun 16 – Jul 14 | 7–21 |
| Mitsuba | Apr 28 | Jun 2 | Jun 2 | Jul 28 – Sep 22 | 50–70 |
| Mizuna | Apr 28 | Jun 2 | Jun 9 | Jul 14 – Aug 11 | 30–45 |
| Mustard Greens | Apr 28 | Jun 2 | Jun 9 | Jul 14 – Sep 15 | 30–50 |
| Napa Cabbage | Apr 28 | Jun 2 | Jun 9 | Aug 4 – Sep 8 | 55–75 |
| Onion | Apr 28 | Jun 2 | Jun 9 | Sep 8 – Oct 27 | 90–120 |
| Pac Choi | Apr 28 | Jun 2 | Jun 9 | Jul 21 – Aug 18 | 40–55 |
| Parsnip | — | Jun 2 | — | Sep 15 – Oct 27 | 100–130 |
| Patty Pan Squash | Apr 28 | Jun 23 | Jun 30 | Aug 18 – Sep 15 | 45–60 |
| Peas | Apr 28 | Jun 2 | Jun 9 | Aug 4 – Sep 29 | 55–70 |
| Peppers | Mar 24 | Jun 23 | Jun 30 | Sep 1 – Nov 10 | 60–90 |
| Pole Beans | Apr 7 | Jun 23 | Jun 30 | Aug 25 – Oct 20 | 55–70 |
| Potatoes | Apr 7 | Jun 23 | Jun 30 | Sep 8 – Nov 17 | 70–120 |
| Pumpkin | Apr 28 | Jun 23 | Jun 30 | Sep 29 – Nov 17 | 85–120 |
| Purslane | Apr 28 | Jun 2 | Jun 9 | Jul 21 – Aug 25 | 40–60 |
| Radicchio | Apr 28 | Jun 2 | Jun 9 | Aug 11 – Sep 15 | 60–80 |
| Radish | — | Jun 2 | — | Jun 30 – Jul 21 | 22–35 |
| Rhubarb | — | — | Jul 7 | — | 365–730 |
| Romanesco | Apr 28 | Jun 2 | Jun 9 | Aug 25 – Oct 6 | 75–100 |
| Rutabaga | — | Jun 2 | — | Aug 25 – Sep 29 | 80–100 |
| Salsify | — | Jun 2 | — | Sep 15 – Oct 27 | 100–130 |
| Savoy Cabbage | Apr 28 | Jun 2 | Jun 9 | Aug 18 – Oct 13 | 70–110 |
| Scallions | Apr 28 | Jun 2 | Jun 9 | Aug 4 – Sep 1 | 50–70 |
| Scarlet Runner Beans | Apr 7 | Jun 23 | Jun 30 | Sep 1 – Oct 6 | 60–80 |
| Shallot | Apr 28 | Jun 2 | Jun 9 | Sep 8 – Oct 27 | 90–120 |
| Shiso | Apr 14 | Jun 16 | Jun 30 | Aug 25 – Oct 20 | 50–70 |
| Snap Peas | Apr 7 | Jun 23 | Jun 30 | Aug 25 – Oct 20 | 55–70 |
| Snow Peas | Apr 28 | Jun 2 | Jun 9 | Aug 4 – Sep 29 | 50–65 |
| Soybeans | — | Jun 23 | — | Sep 15 – Nov 10 | 80–120 |
| Spaghetti Squash | Apr 28 | Jun 23 | Jun 30 | Sep 29 – Oct 27 | 85–100 |
| Spinach | Apr 28 | Jun 2 | Jun 9 | Jul 14 – Sep 15 | 35–50 |
| Squash (Summer) | Apr 28 | Jun 23 | Jun 30 | Aug 18 – Oct 20 | 45–65 |
| Squash (Winter) | Apr 28 | Jun 23 | Jun 30 | Sep 22 – Nov 17 | 80–120 |
| Sunchoke | — | — | Jun 23 | Oct 13 – Nov 17 | 110–150 |
| Sunflower | Apr 7 | Jun 23 | Jun 30 | Sep 8 – Oct 27 | 70–100 |
| Sweet Corn | — | Jun 23 | — | Aug 25 – Oct 6 | 60–90 |
| Tatsoi | Apr 28 | Jun 2 | Jun 9 | Jul 14 – Aug 18 | 35–50 |
| Tomatillo | Apr 7 | Jun 23 | Jun 30 | Sep 1 – Nov 10 | 60–85 |
| Tomatoes | Apr 7 | Jun 23 | Jun 30 | Sep 1 – Nov 10 | 60–85 |
| Turnip | — | Jun 2 | — | Jul 14 – Aug 18 | 40–60 |
| Watercress | Apr 28 | Jun 2 | Jun 9 | Jul 21 – Aug 25 | 40–60 |
| Watermelon | Apr 28 | Jun 23 | Jun 30 | Sep 8 – Oct 27 | 70–100 |
| Wax Beans | — | Jun 23 | — | Aug 18 – Oct 13 | 50–65 |
| Zucchini | Apr 28 | Jun 23 | Jun 30 | Aug 18 – Oct 13 | 45–60 |
🍓 Fruits to Grow in Lemhi County
22 fruits that grow well in Zone 4b with planting dates for Lemhi County.
Show all 22 fruits with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Alpine Strawberries | — | — | Jul 7 | Oct 6 – Dec 1 | 90–180 |
| Aronia | — | — | Jul 7 | — | 730–1095 |
| Blueberries | — | — | Jul 7 | — | 730–1095 |
| Cantaloupe | — | — | Jul 7 | Sep 15 – Oct 20 | 70–90 |
| Cranberries | — | — | Jul 7 | — | 730–1095 |
| Currants | — | — | Jul 7 | — | 730–1095 |
| Elderberries | — | — | Jul 7 | — | 730–1095 |
| Goji Berries | — | — | Jul 7 | — | 730–1095 |
| Gooseberries | — | — | Jul 7 | — | 730–1095 |
| Grapes | — | — | Jul 7 | — | 730–1095 |
| Ground Cherry | — | — | Jul 7 | Sep 15 – Nov 10 | 65–80 |
| Hardy Kiwi | — | — | Jul 7 | — | 1095–1825 |
| Haskaps | — | — | Jul 7 | — | 730–1095 |
| Honeydew | — | — | Jul 7 | Sep 29 – Nov 10 | 80–110 |
| Jostaberry | — | — | Jul 7 | — | 730–1095 |
| Lingonberries | — | — | Jul 7 | — | 730–1095 |
| Medlar | — | — | Jul 7 | — | 1095–1825 |
| Mulberries | — | — | Jul 7 | — | 730–1825 |
| Persimmon | — | — | Jul 7 | — | 1095–2555 |
| Raspberries | — | — | Jul 7 | — | 365–730 |
| Serviceberries | — | — | Jul 7 | — | 730–1095 |
| Strawberries | — | — | Jul 7 | Oct 6 – Dec 1 | 90–365 |
🌿 Herbs to Grow in Lemhi County
32 herbs that grow well in Zone 4b with planting dates for Lemhi County.
Show all 32 herbs with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Angelica | Apr 28 | Jun 2 | Jun 2 | — | 365–730 |
| Anise | Apr 28 | Jun 2 | Jun 2 | Sep 1 – Oct 27 | 90–120 |
| Basil | Apr 14 | Jun 16 | Jun 30 | Aug 25 – Oct 27 | 50–75 |
| Bee Balm | — | — | Jun 16 | Sep 15 – Nov 10 | 90–120 |
| Borage | Apr 28 | Jun 2 | Jun 2 | Jul 28 – Sep 15 | 50–60 |
| Caraway | Apr 28 | Jun 2 | Jun 2 | — | 365–450 |
| Catnip | — | — | Jun 16 | Aug 18 – Oct 20 | 60–80 |
| Chamomile | Apr 28 | Jun 2 | Jun 2 | Aug 4 – Oct 13 | 60–90 |
| Chervil | Apr 28 | Jun 2 | Jun 2 | Jul 14 – Sep 15 | 40–60 |
| Chives | — | — | Jun 16 | Aug 18 – Oct 27 | 60–90 |
| Cilantro | Apr 28 | Jun 2 | Jun 2 | Jul 14 – Sep 15 | 40–60 |
| Comfrey | — | — | Jun 16 | Aug 18 – Oct 27 | 60–90 |
| Dill | Apr 28 | Jun 2 | Jun 2 | Jul 14 – Sep 15 | 40–60 |
| Echinacea | — | — | Jun 16 | Oct 20 – Nov 10 | 120–180 |
| Fennel (herb) | Apr 28 | Jun 2 | Jun 2 | Aug 4 – Oct 13 | 60–90 |
| Garlic Chives | — | — | Jun 16 | Aug 18 – Oct 27 | 60–90 |
| Horehound | — | — | Jun 16 | Sep 1 – Oct 27 | 75–90 |
| Hyssop | — | — | Jun 16 | Aug 25 – Oct 27 | 70–90 |
| Lemon Balm | — | — | Jun 16 | Aug 18 – Oct 6 | 60–70 |
| Lovage | — | — | Jun 16 | Aug 25 – Oct 27 | 70–90 |
| Mint | — | — | Jun 16 | Aug 18 – Oct 27 | 60–90 |
| Oregano | — | — | Jun 16 | Aug 18 – Oct 27 | 60–90 |
| Parsley | Apr 28 | Jun 2 | Jun 2 | Aug 4 – Oct 6 | 60–80 |
| Rue | — | — | Jun 16 | Aug 25 – Oct 27 | 70–90 |
| Sage | — | — | Jun 16 | Sep 1 – Oct 27 | 75–90 |
| Savory | — | — | Jun 16 | Aug 11 – Oct 6 | 50–70 |
| Sorrel | Apr 28 | Jun 2 | Jun 2 | Jul 14 – Sep 15 | 40–60 |
| Tarragon | — | — | Jun 16 | Aug 18 – Oct 27 | 60–90 |
| Thai Basil | Apr 14 | Jun 16 | Jun 30 | Aug 25 – Oct 27 | 50–75 |
| Thyme | — | — | Jun 16 | Aug 25 – Oct 27 | 70–90 |
| Valerian | — | — | Jun 16 | Oct 20 – Nov 10 | 120–180 |
| Yarrow | — | — | Jun 16 | Sep 15 – Nov 10 | 90–120 |
Monthly Planting Guide for Lemhi County
Gardening Guides & Resources
Helpful guides from The Ultimate Homestead to improve your garden in Lemhi County.
Frequently Asked Questions
What planting zone is Lemhi County, ID?
Lemhi 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 Lemhi County, ID?
Based on 31 years of NOAA weather station data, the median last spring frost in Lemhi County falls around June 9. In 8 out of 10 years, last frost lands between May 5 and June 25 — a 51-day window of variability. Use June 25 as your conservative safe-to-plant date for frost-sensitive crops.
When is the first fall frost in Lemhi County, ID?
The median first fall frost in Lemhi County arrives around September 14. In cold years it can arrive as early as August 15; 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 Lemhi County?
Lemhi County has a frost-free growing season of approximately 97 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 0.54 days per decade.
What is the soil like in Lemhi County for gardening?
Lemhi County has predominantly Loam soil with a pH range of 6.2–8.2 and Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.
What is grown commercially in Lemhi County?
Lemhi County has commercial agriculture that includes Potatoes, 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 Lemhi County a good location for home gardening?
Lemhi County scores 41/100 (Moderate) 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.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Lemhi County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.
Get Your Free Garden Planner →Free download. Plan your entire garden season in minutes.
