Jerome County, ID — Planting Guide
Jerome County is in USDA Zone 6a. The average last spring frost is May 10 and the first fall frost is October 4, giving you a growing season of approximately 147 days.
At an elevation of 6,306 ft, Jerome County receives approximately 13.5 in of rainfall annually. Summer highs average 85°F with winter lows around 25°F. The predominant soil type is Loam.
Based on 31 years of NOAA climate station data, the last frost date here varies by 45 days year to year — ranging from April 20 in warm years to June 4 in cold years. The growing season is trending longer by about 4.64 days per decade. Jerome County scores 28/100 (Challenging) on the Microclimate Index.
🌡️ Zone
6a (-10°F to -5°F min)
❄️ Last Frost
May 10
🍂 First Frost
October 4
📅 Growing Season
147 days
⛰️ Elevation
6,306 ft
🌧️ Annual Rainfall
13.5 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 | 1 in | 6 days | — | None |
| Feb | 0.8 in | 6 days | — | None |
| Mar | 1.3 in | 7 days | 3 in | High |
| Apr | 1.6 in | 8 days | 2.7 in | High |
| May | 1.5 in | 7 days | 2.8 in | High |
| Jun | 1 in | 4 days | 3.3 in | Critical |
| Jul | 1.2 in | 5 days | 3.1 in | Critical |
| Aug | 1.3 in | 6 days | 3 in | High |
| Sep | 1.1 in | 6 days | 3.2 in | Critical |
| Oct | 1.1 in | 6 days | 3.2 in | Critical |
| Nov | 0.8 in | 5 days | — | None |
| Dec | 0.8 in | 6 days | — | None |
Annual total: 13.5 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.
Jerome County Soil Profile
Soil Type
Loam
Soil pH
6.8-7.9
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) | Jun 4 | Oct 22 | 140 days |
| Cautious | May 18 | Oct 11 | 146 days |
| Average year | May 10 | Oct 4 | 147 days |
| Optimistic | May 1 | Sep 28 | 150 days |
| Aggressive (risky) | Apr 20 | Sep 18 | 151 days |
Not very — frost dates can vary by ±45 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 4.6 days per decade). Spring is arriving earlier than it used to. Good news for gardeners.
Gardening Difficulty Score
Jerome County has challenging growing conditions. Season extension and careful variety selection are essential.
Local Gardening Help in Jerome 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 Jerome County's climate and soil.
County Extension Office
Jerome 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 Jerome County
Finding local nurseries & garden centers in Jerome County
Why Buy Local
Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Jerome 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 Jerome County ID" or "garden center Jerome 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 Jerome County ID" or check your extension office and local parks department. Facebook groups like "Jerome 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.
Show 6 more succession options
Sunlight & Day Length
Monthly daylight hours and peak sun — critical for onion varieties, photoperiod-sensitive plants, and solar garden planning.
Longest Day
15.1 hours
Summer solstice daylight
Shortest Day
8.9 hours
Winter solstice daylight
Peak Sun Hours
10.9 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 | 9.2 hr | 5.3 hr | Short day |
| February | 10.3 hr | 5.9 hr | Short day |
| March | 11.7 hr | 7.1 hr | Short day |
| April | 13.2 hr | 7.9 hr | Neutral |
| May | 14.4 hr | 9.3 hr | Long day |
| June | 15.1 hr | 10.9 hr | Long day |
| July | 14.8 hr | 10.9 hr | Long day |
| August | 13.7 hr | 9.3 hr | Neutral |
| September | 12.3 hr | 8.6 hr | Neutral |
| October | 10.8 hr | 6.8 hr | Short day |
| November | 9.5 hr | 5.6 hr | Short day |
| December | 8.9 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 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 warm enough from Jul through Aug.
Best Month to Compost
Jun
Microbial activity peaks when soil is warm.
Active Composting
4 months
Short season — insulate pile or use indoor vermicomposting.
View detailed monthly data
| Month | Soil 4" Deep | Soil 8" Deep | Compost Activity | Time to Finish |
|---|---|---|---|---|
| Jan | 14°F | 20°F | ❄️ Dormant | ~36 weeks |
| Feb | 14°F | 20°F | ❄️ Dormant | ~36 weeks |
| Mar | 22°F | 23°F | ❄️ Dormant | ~36 weeks |
| Apr | 34°F | 32°F | ❄️ Dormant | ~36 weeks |
| May | 44°F | 40°F | 🐢 Slow | ~24 weeks |
| Jun | 55°F | 49°F | ♻️ Active | ~14 weeks |
| Jul | 62°F | 55°F | ♻️ Active | ~14 weeks |
| Aug | 63°F | 59°F | ♻️ Active | ~14 weeks |
| Sep | 57°F | 57°F | ♻️ Active | ~14 weeks |
| Oct | 44°F | 48°F | 🐢 Slow | ~24 weeks |
| Nov | 29°F | 36°F | ❄️ Dormant | ~36 weeks |
| Dec | 19°F | 25°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 Jerome 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 6 common pests in your area
| Pest | Risk Level | Peak Months |
|---|---|---|
| Aphids | High | Apr, May, Jun, Jul, Aug, Sep |
| Japanese beetles | High | Jun, Jul, Aug |
| Squash vine borers | Moderate | Jun, Jul |
| Tomato hornworms | Moderate | Jun, Jul, Aug |
| Cucumber beetles | Moderate | May, Jun, Jul |
| Stink bugs | Moderate | 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 Jerome County
Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with county-specific planting dates.
Spring Cover Crops (3 options) — Build soil before the main growing season
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Buckwheat | May 17 | Aug 9 | — | Rapid growth, attracts pollinators, suppresses weeds |
| Sorghum-sudan grass | May 15 | Aug 9 | — | Massive biomass, breaks compaction, suppresses nematodes |
| White clover | Apr 13 | Aug 2 | ✓ 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 | May 30 | Sep 20 | — | Deep roots break compaction, attract pollinators and beneficial insects |
Fall Cover Crops (7 options) — Plant after harvest to protect soil over winter
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Austrian winter peas | Jul 30 | Apr 19 | ✓ Yes | Fixes nitrogen, good for heavy clay soils |
| Crimson clover | Aug 2 | Apr 19 | ✓ Yes | Fixes nitrogen, attracts pollinators in spring |
| Daikon radish | Aug 10 | Apr 19 | — | Deep taproot breaks compaction, excellent for clay soils |
| Hairy vetch | Jul 28 | Apr 26 | ✓ Yes | Excellent nitrogen fixer, good for depleted soils |
| Oats | Sep 6 | Apr 26 | — | Quick biomass, winterkills in cold zones — no spring tillage needed |
| Winter rye | Jul 12 | Apr 19 | — | Suppresses weeds, prevents erosion, breaks up compacted soil |
| Winter wheat | Jul 2 | Apr 19 | — | Erosion control, weed suppression, good biomass |
Wind & Microclimate
Wind dries soil, stresses plants, and affects frost patterns. Understanding your exposure helps with garden placement.
Seasonal Wind Speed
Spring: 16 mph Summer: 11 mph
Fall: 13 mph Winter: 16 mph
Prevailing wind: W. Windy area — plant a windbreak hedge on the W side of your garden.
Windbreak Benefit
7.4/10
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 1,861 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
6,728 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
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 13.5 inches of rain per year
- A 1,000 sq ft roof can collect roughly 6,728 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 Jerome County
Soil Type
Loam
Soil pH 6.8–7.9 · Moderately 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
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.
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 Jerome County
108 vegetables that grow well in Zone 6a with planting dates for Jerome County.
Show all 108 vegetables with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Acorn Squash | Apr 5 | May 17 | May 24 | Aug 16 – Sep 20 | 80–100 |
| Amaranth | Mar 15 | May 17 | May 24 | Aug 23 – Oct 11 | 90–120 |
| Arugula | Apr 5 | Apr 26 | May 10 | Jun 14 – Aug 16 | 30–50 |
| Asparagus | — | — | May 24 | — | 730–1095 |
| Beets | — | Apr 26 | — | Jun 21 – Jul 19 | 50–70 |
| Belgian Endive | Apr 5 | Apr 26 | May 10 | Aug 30 – Oct 25 | 110–150 |
| Bitter Melon | Mar 15 | May 17 | May 24 | Jul 26 – Sep 6 | 60–90 |
| Black Beans | — | May 17 | — | Aug 16 – Oct 4 | 90–120 |
| Bok Choy | Apr 5 | Apr 26 | May 10 | Jun 21 – Jul 26 | 40–60 |
| Broccoli | Apr 5 | Apr 26 | May 10 | Jul 12 – Aug 23 | 60–90 |
| Broccoli Rabe | Apr 5 | Apr 26 | May 10 | Jun 21 – Jul 26 | 40–60 |
| Brussels Sprouts | Apr 5 | Apr 26 | May 10 | Aug 9 – Oct 4 | 90–130 |
| Butternut Squash | Apr 5 | May 17 | May 24 | Aug 23 – Sep 27 | 85–110 |
| Cabbage | Apr 5 | Apr 26 | May 10 | Jul 12 – Sep 6 | 60–100 |
| Calabash | Mar 15 | May 17 | May 24 | Aug 16 – Oct 11 | 80–120 |
| Carrots | — | Apr 26 | — | Jun 28 – Aug 2 | 60–80 |
| Cauliflower | Apr 5 | Apr 26 | May 10 | Jul 5 – Sep 6 | 55–100 |
| Celeriac | Apr 5 | Apr 26 | May 10 | Aug 23 – Sep 27 | 100–120 |
| Celery | Apr 5 | Apr 26 | May 10 | Aug 2 – Sep 27 | 80–120 |
| Celtuce | Apr 5 | Apr 26 | May 10 | Jul 12 – Aug 23 | 60–90 |
| Chard | Apr 5 | Apr 26 | May 10 | Jul 5 – Aug 23 | 50–60 |
| Chickpeas | Apr 5 | Apr 26 | May 10 | Aug 2 – Sep 13 | 80–110 |
| Chicory | Apr 5 | Apr 26 | May 10 | Jul 12 – Aug 23 | 60–85 |
| Chinese Cabbage | Apr 5 | Apr 26 | May 10 | Jul 5 – Aug 2 | 50–70 |
| Christmas Lima Beans | Mar 15 | May 17 | May 24 | Aug 16 – Sep 20 | 80–100 |
| Collard Greens | Apr 5 | Apr 26 | May 10 | Jul 5 – Sep 6 | 55–75 |
| Corn | — | May 17 | — | Jul 19 – Sep 13 | 60–100 |
| Cowpeas | — | May 17 | — | Jul 19 – Aug 30 | 60–90 |
| Cress | Apr 5 | Apr 26 | May 10 | May 24 – Jun 14 | 14–21 |
| Crookneck Squash | Apr 5 | May 17 | May 24 | Jul 12 – Aug 9 | 45–60 |
| Crosne | — | Apr 26 | — | Sep 27 – Nov 8 | 150–200 |
| Cucumber | Apr 5 | May 17 | May 24 | Jul 19 – Sep 13 | 50–70 |
| Daikon | — | Apr 26 | — | Jun 21 – Jul 19 | 50–70 |
| Delicata Squash | Apr 5 | May 17 | May 24 | Aug 16 – Sep 20 | 80–100 |
| Edamame | — | May 17 | — | Aug 2 – Sep 13 | 75–100 |
| Eggplant | Mar 1 | May 17 | May 24 | Aug 2 – Oct 4 | 65–85 |
| Endive | Apr 5 | Apr 26 | May 10 | Jun 28 – Aug 2 | 45–65 |
| Escarole | Apr 5 | Apr 26 | May 10 | Jul 5 – Aug 2 | 50–70 |
| Fava Beans | Apr 5 | Apr 26 | May 10 | Jul 26 – Sep 6 | 75–100 |
| Fennel | Mar 15 | May 17 | May 24 | Jul 26 – Sep 6 | 60–90 |
| Garlic | — | — | — | — | 90–240 |
| Green Beans | — | May 17 | — | Jul 12 – Sep 6 | 50–65 |
| Horseradish | — | — | May 24 | Sep 27 – Dec 6 | 120–180 |
| Hot Peppers | Mar 1 | May 17 | May 24 | Aug 2 – Nov 8 | 70–120 |
| Hubbard Squash | Apr 5 | May 17 | May 24 | Sep 6 – Oct 11 | 100–120 |
| Kabocha | Apr 5 | May 17 | May 24 | Aug 23 – Sep 20 | 85–100 |
| Kai Lan | Apr 5 | Apr 26 | May 10 | Jun 28 – Jul 26 | 45–60 |
| Kale | Apr 5 | Apr 26 | May 10 | Jul 5 – Aug 30 | 50–70 |
| Kidney Beans | — | May 17 | — | Aug 16 – Sep 20 | 85–110 |
| Kohlrabi | Apr 5 | Apr 26 | May 10 | Jun 28 – Aug 2 | 45–65 |
| Komatsuna | Apr 5 | Apr 26 | May 10 | Jun 14 – Jul 19 | 35–50 |
| Leeks | Apr 5 | Apr 26 | May 10 | Aug 9 – Oct 25 | 90–150 |
| Lentils | Apr 5 | Apr 26 | May 10 | Aug 2 – Sep 13 | 80–110 |
| Lettuce | Apr 5 | Apr 26 | May 10 | Jun 14 – Aug 23 | 30–60 |
| Lima Beans | — | May 17 | — | Jul 19 – Aug 30 | 60–90 |
| Loofah | Mar 15 | May 17 | May 24 | Sep 6 – Nov 8 | 100–150 |
| Luffa | Mar 15 | May 17 | May 24 | Aug 23 – Nov 8 | 90–150 |
| Mache | Apr 5 | Apr 26 | May 10 | Jun 21 – Jul 26 | 40–60 |
| Melon | Apr 5 | May 17 | May 24 | Aug 2 – Sep 20 | 70–100 |
| Microgreens | Apr 5 | Apr 26 | May 10 | May 17 – Jun 14 | 7–21 |
| Mitsuba | Apr 5 | Apr 26 | May 3 | Jun 28 – Aug 23 | 50–70 |
| Mizuna | Apr 5 | Apr 26 | May 10 | Jun 14 – Jul 12 | 30–45 |
| Mustard Greens | Apr 5 | Apr 26 | May 10 | Jun 14 – Aug 16 | 30–50 |
| Napa Cabbage | Apr 5 | Apr 26 | May 10 | Jul 5 – Aug 9 | 55–75 |
| New Zealand Spinach | Mar 15 | May 17 | May 24 | Jul 19 – Aug 16 | 55–70 |
| Okra | Mar 15 | May 17 | May 24 | Jul 19 – Sep 13 | 50–65 |
| Onion | Apr 5 | Apr 26 | May 10 | Aug 9 – Sep 27 | 90–120 |
| Pac Choi | Apr 5 | Apr 26 | May 10 | Jun 21 – Jul 19 | 40–55 |
| Parsnip | — | Apr 26 | — | Aug 9 – Sep 20 | 100–130 |
| Patty Pan Squash | Apr 5 | May 17 | May 24 | Jul 12 – Aug 9 | 45–60 |
| Peas | Apr 5 | Apr 26 | May 10 | Jul 5 – Aug 30 | 55–70 |
| Peppers | Mar 1 | May 17 | May 24 | Jul 26 – Oct 4 | 60–90 |
| Pole Beans | Mar 15 | May 17 | May 24 | Jul 19 – Sep 13 | 55–70 |
| Potatoes | Mar 15 | May 17 | May 24 | Aug 2 – Oct 11 | 70–120 |
| Pumpkin | Apr 5 | May 17 | May 24 | Aug 23 – Oct 11 | 85–120 |
| Purslane | Apr 5 | Apr 26 | May 10 | Jun 21 – Jul 26 | 40–60 |
| Radicchio | Apr 5 | Apr 26 | May 10 | Jul 12 – Aug 16 | 60–80 |
| Radish | — | Apr 26 | — | May 24 – Jun 14 | 22–35 |
| Rhubarb | — | — | May 31 | — | 365–730 |
| Romanesco | Apr 5 | Apr 26 | May 10 | Jul 26 – Sep 6 | 75–100 |
| Rutabaga | — | Apr 26 | — | Jul 19 – Aug 23 | 80–100 |
| Salsify | — | Apr 26 | — | Aug 9 – Sep 20 | 100–130 |
| Savoy Cabbage | Apr 5 | Apr 26 | May 10 | Jul 19 – Sep 13 | 70–110 |
| Scallions | Apr 5 | Apr 26 | May 10 | Jul 5 – Aug 2 | 50–70 |
| Scarlet Runner Beans | Mar 15 | May 17 | May 24 | Jul 26 – Aug 30 | 60–80 |
| Shallot | Apr 5 | Apr 26 | May 10 | Aug 9 – Sep 27 | 90–120 |
| Shiso | Mar 22 | May 17 | May 24 | Jul 19 – Sep 13 | 50–70 |
| Snap Peas | Mar 15 | May 17 | May 24 | Jul 19 – Sep 13 | 55–70 |
| Snow Peas | Apr 5 | Apr 26 | May 10 | Jul 5 – Aug 30 | 50–65 |
| Soybeans | — | May 17 | — | Aug 9 – Oct 4 | 80–120 |
| Spaghetti Squash | Apr 5 | May 17 | May 24 | Aug 23 – Sep 20 | 85–100 |
| Spinach | Apr 5 | Apr 26 | May 10 | Jun 14 – Aug 16 | 35–50 |
| Squash (Summer) | Apr 5 | May 17 | May 24 | Jul 12 – Sep 13 | 45–65 |
| Squash (Winter) | Apr 5 | May 17 | May 24 | Aug 16 – Oct 11 | 80–120 |
| Sunchoke | — | — | May 24 | Sep 13 – Nov 8 | 110–150 |
| Sunflower | Mar 15 | May 17 | May 24 | Aug 2 – Sep 20 | 70–100 |
| Sweet Corn | — | May 17 | — | Jul 19 – Aug 30 | 60–90 |
| Sweet Potatoes | Mar 15 | May 17 | May 24 | Aug 23 – Oct 11 | 90–120 |
| Tatsoi | Apr 5 | Apr 26 | May 10 | Jun 14 – Jul 19 | 35–50 |
| Tomatillo | Mar 15 | May 17 | May 24 | Jul 26 – Oct 4 | 60–85 |
| Tomatoes | Mar 15 | May 17 | May 24 | Jul 26 – Oct 4 | 60–85 |
| Turnip | — | Apr 26 | — | Jun 7 – Jul 12 | 40–60 |
| Watercress | Apr 5 | Apr 26 | May 10 | Jun 21 – Jul 26 | 40–60 |
| Watermelon | Apr 5 | May 17 | May 24 | Aug 2 – Sep 20 | 70–100 |
| Wax Beans | — | May 17 | — | Jul 12 – Sep 6 | 50–65 |
| Winter Melon | Mar 15 | May 17 | May 24 | Aug 23 – Oct 11 | 90–120 |
| Yard Long Beans | Mar 15 | May 17 | May 24 | Jul 19 – Aug 30 | 55–80 |
| Zucchini | Apr 5 | May 17 | May 24 | Jul 12 – Sep 6 | 45–60 |
🍓 Fruits to Grow in Jerome County
27 fruits that grow well in Zone 6a with planting dates for Jerome County.
Show all 27 fruits with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Alpine Strawberries | — | — | May 31 | Aug 30 – Dec 13 | 90–180 |
| Aronia | — | — | May 31 | — | 730–1095 |
| Blackberries | — | — | May 31 | — | 365–730 |
| Blueberries | — | — | May 31 | — | 730–1095 |
| Boysenberries | — | — | May 31 | — | 365–730 |
| Cantaloupe | — | — | May 31 | Aug 9 – Sep 13 | 70–90 |
| Che Fruit | — | — | May 31 | — | 1095–1825 |
| Cranberries | — | — | May 31 | — | 730–1095 |
| Currants | — | — | May 31 | — | 730–1095 |
| Elderberries | — | — | May 31 | — | 730–1095 |
| Goji Berries | — | — | May 31 | — | 730–1095 |
| Gooseberries | — | — | May 31 | — | 730–1095 |
| Grapes | — | — | May 31 | — | 730–1095 |
| Ground Cherry | — | — | May 31 | Aug 9 – Oct 4 | 65–80 |
| Hardy Kiwi | — | — | May 31 | — | 1095–1825 |
| Haskaps | — | — | May 31 | — | 730–1095 |
| Honeydew | — | — | May 31 | Aug 23 – Oct 4 | 80–110 |
| Jostaberry | — | — | May 31 | — | 730–1095 |
| Lingonberries | — | — | May 31 | — | 730–1095 |
| Medlar | — | — | May 31 | — | 1095–1825 |
| Mulberries | — | — | May 31 | — | 730–1825 |
| Pawpaw | — | — | May 31 | — | 1095–2555 |
| Persimmon | — | — | May 31 | — | 1095–2555 |
| Quince | — | — | May 31 | — | 1095–1825 |
| Raspberries | — | — | May 31 | — | 365–730 |
| Serviceberries | — | — | May 31 | — | 730–1095 |
| Strawberries | — | — | May 31 | Aug 30 – Dec 13 | 90–365 |
🌿 Herbs to Grow in Jerome County
38 herbs that grow well in Zone 6a with planting dates for Jerome County.
Show all 38 herbs with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Angelica | Apr 5 | Apr 26 | May 3 | — | 365–730 |
| Anise | Apr 5 | Apr 26 | May 3 | Aug 2 – Oct 18 | 90–120 |
| Basil | Mar 22 | May 17 | May 24 | Jul 19 – Sep 20 | 50–75 |
| Bee Balm | — | — | May 17 | Aug 16 – Nov 1 | 90–120 |
| Borage | Apr 5 | Apr 26 | May 3 | Jun 28 – Aug 16 | 50–60 |
| Caraway | Apr 5 | Apr 26 | May 3 | — | 365–450 |
| Catnip | — | — | May 17 | Jul 19 – Sep 20 | 60–80 |
| Chamomile | Apr 5 | Apr 26 | May 3 | Jul 5 – Sep 13 | 60–90 |
| Chervil | Apr 5 | Apr 26 | May 3 | Jun 14 – Aug 16 | 40–60 |
| Chives | — | — | May 17 | Jul 19 – Sep 27 | 60–90 |
| Cilantro | Apr 5 | Apr 26 | May 3 | Jun 14 – Aug 16 | 40–60 |
| Comfrey | — | — | May 17 | Jul 19 – Sep 27 | 60–90 |
| Cumin | Apr 5 | Apr 26 | May 3 | Aug 16 – Oct 18 | 100–120 |
| Dill | Apr 5 | Apr 26 | May 3 | Jun 14 – Aug 16 | 40–60 |
| Echinacea | — | — | May 17 | Sep 20 – Nov 29 | 120–180 |
| Epazote | Mar 22 | May 17 | May 24 | Jul 12 – Sep 6 | 45–60 |
| Fennel (herb) | Apr 5 | Apr 26 | May 3 | Jul 5 – Sep 13 | 60–90 |
| Feverfew | — | — | May 17 | Aug 16 – Nov 1 | 90–120 |
| Garlic Chives | — | — | May 17 | Jul 19 – Sep 27 | 60–90 |
| Horehound | — | — | May 17 | Aug 2 – Sep 27 | 75–90 |
| Hyssop | — | — | May 17 | Jul 26 – Sep 27 | 70–90 |
| Lavender | — | — | May 17 | Aug 16 – Nov 29 | 90–200 |
| Lemon Balm | — | — | May 17 | Jul 19 – Sep 6 | 60–70 |
| Lemon Thyme | — | — | May 17 | Jul 26 – Sep 27 | 70–90 |
| Lovage | — | — | May 17 | Jul 26 – Sep 27 | 70–90 |
| Marjoram | — | — | May 17 | Jul 19 – Sep 27 | 60–90 |
| Mint | — | — | May 17 | Jul 19 – Sep 27 | 60–90 |
| Oregano | — | — | May 17 | Jul 19 – Sep 27 | 60–90 |
| Parsley | Apr 5 | Apr 26 | May 3 | Jul 5 – Sep 6 | 60–80 |
| Rue | — | — | May 17 | Jul 26 – Sep 27 | 70–90 |
| Sage | — | — | May 17 | Aug 2 – Sep 27 | 75–90 |
| Savory | — | — | May 17 | Jul 12 – Sep 6 | 50–70 |
| Sorrel | Apr 5 | Apr 26 | May 3 | Jun 14 – Aug 16 | 40–60 |
| Tarragon | — | — | May 17 | Jul 19 – Sep 27 | 60–90 |
| Thai Basil | Mar 22 | May 17 | May 24 | Jul 19 – Sep 20 | 50–75 |
| Thyme | — | — | May 17 | Jul 26 – Sep 27 | 70–90 |
| Valerian | — | — | May 17 | Sep 20 – Nov 29 | 120–180 |
| Yarrow | — | — | May 17 | Aug 16 – Nov 1 | 90–120 |
Monthly Planting Guide for Jerome County
Gardening Guides & Resources
Helpful guides from The Ultimate Homestead to improve your garden in Jerome County.
Frequently Asked Questions
What planting zone is Jerome County, ID?
Jerome County is in USDA Hardiness Zone 6a. This zone classification determines which perennial plants survive winter and sets the baseline for frost timing across the county.
When is the last frost in Jerome County, ID?
Based on 31 years of NOAA weather station data, the median last spring frost in Jerome County falls around May 10. In 8 out of 10 years, last frost lands between April 20 and June 4 — a 45-day window of variability. Use June 4 as your conservative safe-to-plant date for frost-sensitive crops.
When is the first fall frost in Jerome County, ID?
The median first fall frost in Jerome County arrives around October 4. In cold years it can arrive as early as September 18; in mild years as late as October 22. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.
How long is the growing season in Jerome County?
Jerome 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 4.64 days per decade.
What is the soil like in Jerome County for gardening?
Jerome County has predominantly Loam soil with a pH range of 6.8–7.9 and Moderately Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.
What is grown commercially in Jerome County?
Jerome County has commercial agriculture that includes Potatoes, Hay, Wheat, Barley, Cattle. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.
Is Jerome County a good location for home gardening?
Jerome County scores 28/100 (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.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Jerome County gardeners in Zone 6a 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.
