Ada County, ID — Planting Guide
Ada County is in USDA Zone 6b. The average last spring frost is April 23 and the first fall frost is October 16, giving you a growing season of approximately 176 days.
At an elevation of 4,372 ft, Ada County receives approximately 19.8 in of rainfall annually. Summer highs average 90°F with winter lows around 24°F. The predominant soil type is Loam.
Based on 31 years of NOAA climate station data, the last frost date here varies by 43 days year to year — ranging from March 30 in warm years to May 13 in cold years. The growing season is trending longer by about 5.02 days per decade. Ada County scores 34/100 (Challenging) on the Microclimate Index.
🌡️ Zone
6b (-5°F to 0°F min)
❄️ Last Frost
April 23
🍂 First Frost
October 16
📅 Growing Season
176 days
⛰️ Elevation
4,372 ft
🌧️ Annual Rainfall
19.8 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 | 1.4 in | 6 days | — | None |
| Feb | 1.2 in | 5 days | — | None |
| Mar | 1.5 in | 7 days | 2.8 in | High |
| Apr | 2 in | 7 days | 2.3 in | High |
| May | 2.4 in | 8 days | 1.9 in | High |
| Jun | 1.4 in | 5 days | 2.9 in | High |
| Jul | 1.8 in | 5 days | 2.5 in | High |
| Aug | 2.4 in | 6 days | 1.9 in | High |
| Sep | 1.5 in | 5 days | 2.8 in | High |
| Oct | 1.8 in | 6 days | 2.5 in | High |
| Nov | 1.3 in | 5 days | — | None |
| Dec | 1.2 in | 6 days | — | None |
Annual total: 19.9 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.
Ada County Soil Profile
Soil Type
Loam
Soil pH
6.4-7.7
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 13 | Nov 3 | 174 days |
| Cautious | May 3 | Oct 25 | 175 days |
| Average year | Apr 23 | Oct 16 | 176 days |
| Optimistic | Apr 15 | Oct 10 | 178 days |
| Aggressive (risky) | Mar 30 | Sep 30 | 184 days |
Not very — frost dates can vary by ±43 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 5 days per decade). Spring is arriving earlier than it used to. Good news for gardeners.
Gardening Difficulty Score
Ada County has challenging growing conditions. Season extension and careful variety selection are essential.
Local Gardening Help in Ada 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 Ada County's climate and soil.
County Extension Office
Ada 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 Ada County
Finding local nurseries & garden centers in Ada County
Why Buy Local
Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Ada 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 Ada County ID" or "garden center Ada 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 Ada County ID" or check your extension office and local parks department. Facebook groups like "Ada 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
15.2 hours
Summer solstice daylight
Shortest Day
8.8 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 | 9.1 hr | 4.9 hr | Short day |
| February | 10.3 hr | 5.8 hr | Short day |
| March | 11.6 hr | 7.1 hr | Short day |
| April | 13.2 hr | 7.5 hr | Neutral |
| May | 14.5 hr | 8.6 hr | Long day |
| June | 15.2 hr | 10.8 hr | Long day |
| July | 14.9 hr | 10.3 hr | Long day |
| August | 13.8 hr | 9.3 hr | Neutral |
| September | 12.3 hr | 8.7 hr | Neutral |
| October | 10.8 hr | 7.2 hr | Short day |
| November | 9.4 hr | 5.4 hr | Short day |
| December | 8.8 hr | 5 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 Jun through Sep.
Best Month to Compost
Jul
Microbial activity peaks when soil is warm.
Active Composting
6 months
Solid season. Piles go dormant in winter.
View detailed monthly data
| Month | Soil 4" Deep | Soil 8" Deep | Compost Activity | Time to Finish |
|---|---|---|---|---|
| Jan | 18°F | 25°F | ❄️ Dormant | ~36 weeks |
| Feb | 20°F | 25°F | ❄️ Dormant | ~36 weeks |
| Mar | 25°F | 29°F | ❄️ Dormant | ~36 weeks |
| Apr | 38°F | 38°F | ❄️ Dormant | ~36 weeks |
| May | 51°F | 49°F | ♻️ Active | ~14 weeks |
| Jun | 61°F | 58°F | ♻️ Active | ~14 weeks |
| Jul | 69°F | 63°F | 🔥 Peak | ~8 weeks |
| Aug | 72°F | 65°F | 🔥 Peak | ~8 weeks |
| Sep | 62°F | 61°F | ♻️ Active | ~14 weeks |
| Oct | 51°F | 53°F | ♻️ Active | ~14 weeks |
| Nov | 36°F | 42°F | ❄️ Dormant | ~36 weeks |
| Dec | 25°F | 32°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 Ada 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 | Moderate | Jun, Jul, Aug |
| Squash vine borers | Moderate | Jun, Jul |
| Tomato hornworms | Moderate | Jun, Jul, Aug |
| Cucumber beetles | Low | May, Jun, Jul |
| Stink bugs | Low | 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 Ada County
Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with county-specific planting dates.
Fall Cover Crops (7 options) — Plant after harvest to protect soil over winter
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Austrian winter peas | Aug 13 | Apr 9 | ✓ Yes | Fixes nitrogen, good for heavy clay soils |
| Crimson clover | Aug 6 | Apr 9 | ✓ Yes | Fixes nitrogen, attracts pollinators in spring |
| Daikon radish | Aug 29 | Apr 2 | — | Deep taproot breaks compaction, excellent for clay soils |
| Hairy vetch | Aug 6 | Apr 9 | ✓ Yes | Excellent nitrogen fixer, good for depleted soils |
| Oats | Sep 12 | Apr 2 | — | Quick biomass, winterkills in cold zones — no spring tillage needed |
| Winter rye | Jul 11 | Apr 9 | — | Suppresses weeds, prevents erosion, breaks up compacted soil |
| Winter wheat | Jul 15 | Apr 2 | — | Erosion control, weed suppression, good biomass |
Spring Cover Crops (3 options) — Build soil before the main growing season
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Buckwheat | May 2 | Aug 7 | — | Rapid growth, attracts pollinators, suppresses weeds |
| Sorghum-sudan grass | Apr 30 | Aug 7 | — | Massive biomass, breaks compaction, suppresses nematodes |
| White clover | Mar 24 | Aug 21 | ✓ 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 18 | Oct 2 | — | 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: 15 mph Summer: 10 mph
Fall: 13 mph Winter: 14 mph
Prevailing wind: W. Windy area — plant a windbreak hedge on the W side of your garden.
Windbreak Benefit
6.5/10
Moderately beneficial — a simple fence or trellis can protect delicate crops from wind stress.
Frost Pocket Risk
High
Hilly terrain with 1,500 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
9,918 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
Apr, May, Jul, 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 19.9 inches of rain per year
- A 1,000 sq ft roof can collect roughly 9,918 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 Ada County
Soil Type
Loam
Soil pH 6.4–7.7 · 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
176-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 Ada County
108 vegetables that grow well in Zone 6b with planting dates for Ada County.
Show all 108 vegetables with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Acorn Squash | Mar 19 | Apr 30 | May 7 | Jul 30 – Sep 3 | 80–100 |
| Amaranth | Feb 26 | Apr 30 | May 7 | Aug 6 – Sep 24 | 90–120 |
| Arugula | Mar 19 | Apr 9 | Apr 23 | May 28 – Jul 30 | 30–50 |
| Asparagus | — | — | May 7 | — | 730–1095 |
| Beets | — | Apr 9 | — | Jun 4 – Jul 2 | 50–70 |
| Belgian Endive | Mar 19 | Apr 9 | Apr 23 | Aug 13 – Oct 8 | 110–150 |
| Bitter Melon | Feb 26 | Apr 30 | May 7 | Jul 9 – Aug 20 | 60–90 |
| Black Beans | — | Apr 30 | — | Jul 30 – Sep 17 | 90–120 |
| Bok Choy | Mar 19 | Apr 9 | Apr 23 | Jun 4 – Jul 9 | 40–60 |
| Broccoli | Mar 19 | Apr 9 | Apr 23 | Jun 25 – Aug 6 | 60–90 |
| Broccoli Rabe | Mar 19 | Apr 9 | Apr 23 | Jun 4 – Jul 9 | 40–60 |
| Brussels Sprouts | Mar 19 | Apr 9 | Apr 23 | Jul 23 – Sep 17 | 90–130 |
| Butternut Squash | Mar 19 | Apr 30 | May 7 | Aug 6 – Sep 10 | 85–110 |
| Cabbage | Mar 19 | Apr 9 | Apr 23 | Jun 25 – Aug 20 | 60–100 |
| Calabash | Feb 26 | Apr 30 | May 7 | Jul 30 – Sep 24 | 80–120 |
| Carrots | — | Apr 9 | — | Jun 11 – Jul 16 | 60–80 |
| Cauliflower | Mar 19 | Apr 9 | Apr 23 | Jun 18 – Aug 20 | 55–100 |
| Celeriac | Mar 19 | Apr 9 | Apr 23 | Aug 6 – Sep 10 | 100–120 |
| Celery | Mar 19 | Apr 9 | Apr 23 | Jul 16 – Sep 10 | 80–120 |
| Celtuce | Mar 19 | Apr 9 | Apr 23 | Jun 25 – Aug 6 | 60–90 |
| Chard | Mar 19 | Apr 9 | Apr 23 | Jun 18 – Aug 6 | 50–60 |
| Chickpeas | Mar 19 | Apr 9 | Apr 23 | Jul 16 – Aug 27 | 80–110 |
| Chicory | Mar 19 | Apr 9 | Apr 23 | Jun 25 – Aug 6 | 60–85 |
| Chinese Cabbage | Mar 19 | Apr 9 | Apr 23 | Jun 18 – Jul 16 | 50–70 |
| Christmas Lima Beans | Feb 26 | Apr 30 | May 7 | Jul 30 – Sep 3 | 80–100 |
| Collard Greens | Mar 19 | Apr 9 | Apr 23 | Jun 18 – Aug 20 | 55–75 |
| Corn | — | Apr 30 | — | Jul 2 – Aug 27 | 60–100 |
| Cowpeas | — | Apr 30 | — | Jul 2 – Aug 13 | 60–90 |
| Cress | Mar 19 | Apr 9 | Apr 23 | May 7 – May 28 | 14–21 |
| Crookneck Squash | Mar 19 | Apr 30 | May 7 | Jun 25 – Jul 23 | 45–60 |
| Crosne | — | Apr 9 | — | Sep 10 – Oct 22 | 150–200 |
| Cucumber | Mar 19 | Apr 30 | May 7 | Jul 2 – Aug 27 | 50–70 |
| Daikon | — | Apr 9 | — | Jun 4 – Jul 2 | 50–70 |
| Delicata Squash | Mar 19 | Apr 30 | May 7 | Jul 30 – Sep 3 | 80–100 |
| Edamame | — | Apr 30 | — | Jul 16 – Aug 27 | 75–100 |
| Eggplant | Feb 12 | Apr 30 | May 7 | Jul 16 – Sep 17 | 65–85 |
| Endive | Mar 19 | Apr 9 | Apr 23 | Jun 11 – Jul 16 | 45–65 |
| Escarole | Mar 19 | Apr 9 | Apr 23 | Jun 18 – Jul 16 | 50–70 |
| Fava Beans | Mar 19 | Apr 9 | Apr 23 | Jul 9 – Aug 20 | 75–100 |
| Fennel | Feb 26 | Apr 30 | May 7 | Jul 9 – Aug 20 | 60–90 |
| Garlic | — | — | — | — | 90–240 |
| Green Beans | — | Apr 30 | — | Jun 25 – Aug 20 | 50–65 |
| Horseradish | — | — | May 7 | Sep 10 – Nov 19 | 120–180 |
| Hot Peppers | Feb 12 | Apr 30 | May 7 | Jul 16 – Oct 22 | 70–120 |
| Hubbard Squash | Mar 19 | Apr 30 | May 7 | Aug 20 – Sep 24 | 100–120 |
| Kabocha | Mar 19 | Apr 30 | May 7 | Aug 6 – Sep 3 | 85–100 |
| Kai Lan | Mar 19 | Apr 9 | Apr 23 | Jun 11 – Jul 9 | 45–60 |
| Kale | Mar 19 | Apr 9 | Apr 23 | Jun 18 – Aug 13 | 50–70 |
| Kidney Beans | — | Apr 30 | — | Jul 30 – Sep 3 | 85–110 |
| Kohlrabi | Mar 19 | Apr 9 | Apr 23 | Jun 11 – Jul 16 | 45–65 |
| Komatsuna | Mar 19 | Apr 9 | Apr 23 | May 28 – Jul 2 | 35–50 |
| Leeks | Mar 19 | Apr 9 | Apr 23 | Jul 23 – Oct 8 | 90–150 |
| Lentils | Mar 19 | Apr 9 | Apr 23 | Jul 16 – Aug 27 | 80–110 |
| Lettuce | Mar 19 | Apr 9 | Apr 23 | May 28 – Aug 6 | 30–60 |
| Lima Beans | — | Apr 30 | — | Jul 2 – Aug 13 | 60–90 |
| Loofah | Feb 26 | Apr 30 | May 7 | Aug 20 – Oct 22 | 100–150 |
| Luffa | Feb 26 | Apr 30 | May 7 | Aug 6 – Oct 22 | 90–150 |
| Mache | Mar 19 | Apr 9 | Apr 23 | Jun 4 – Jul 9 | 40–60 |
| Melon | Mar 19 | Apr 30 | May 7 | Jul 16 – Sep 3 | 70–100 |
| Microgreens | Mar 19 | Apr 9 | Apr 23 | Apr 30 – May 28 | 7–21 |
| Mitsuba | Mar 19 | Apr 9 | Apr 16 | Jun 11 – Aug 6 | 50–70 |
| Mizuna | Mar 19 | Apr 9 | Apr 23 | May 28 – Jun 25 | 30–45 |
| Mustard Greens | Mar 19 | Apr 9 | Apr 23 | May 28 – Jul 30 | 30–50 |
| Napa Cabbage | Mar 19 | Apr 9 | Apr 23 | Jun 18 – Jul 23 | 55–75 |
| New Zealand Spinach | Feb 26 | Apr 30 | May 7 | Jul 2 – Jul 30 | 55–70 |
| Okra | Feb 26 | Apr 30 | May 7 | Jul 2 – Aug 27 | 50–65 |
| Onion | Mar 19 | Apr 9 | Apr 23 | Jul 23 – Sep 10 | 90–120 |
| Pac Choi | Mar 19 | Apr 9 | Apr 23 | Jun 4 – Jul 2 | 40–55 |
| Parsnip | — | Apr 9 | — | Jul 23 – Sep 3 | 100–130 |
| Patty Pan Squash | Mar 19 | Apr 30 | May 7 | Jun 25 – Jul 23 | 45–60 |
| Peas | Mar 19 | Apr 9 | Apr 23 | Jun 18 – Aug 13 | 55–70 |
| Peppers | Feb 12 | Apr 30 | May 7 | Jul 9 – Sep 17 | 60–90 |
| Pole Beans | Feb 26 | Apr 30 | May 7 | Jul 2 – Aug 27 | 55–70 |
| Potatoes | Feb 26 | Apr 30 | May 7 | Jul 16 – Sep 24 | 70–120 |
| Pumpkin | Mar 19 | Apr 30 | May 7 | Aug 6 – Sep 24 | 85–120 |
| Purslane | Mar 19 | Apr 9 | Apr 23 | Jun 4 – Jul 9 | 40–60 |
| Radicchio | Mar 19 | Apr 9 | Apr 23 | Jun 25 – Jul 30 | 60–80 |
| Radish | — | Apr 9 | — | May 7 – May 28 | 22–35 |
| Rhubarb | — | — | May 14 | — | 365–730 |
| Romanesco | Mar 19 | Apr 9 | Apr 23 | Jul 9 – Aug 20 | 75–100 |
| Rutabaga | — | Apr 9 | — | Jul 2 – Aug 6 | 80–100 |
| Salsify | — | Apr 9 | — | Jul 23 – Sep 3 | 100–130 |
| Savoy Cabbage | Mar 19 | Apr 9 | Apr 23 | Jul 2 – Aug 27 | 70–110 |
| Scallions | Mar 19 | Apr 9 | Apr 23 | Jun 18 – Jul 16 | 50–70 |
| Scarlet Runner Beans | Feb 26 | Apr 30 | May 7 | Jul 9 – Aug 13 | 60–80 |
| Shallot | Mar 19 | Apr 9 | Apr 23 | Jul 23 – Sep 10 | 90–120 |
| Shiso | Mar 5 | Apr 30 | May 7 | Jul 2 – Aug 27 | 50–70 |
| Snap Peas | Feb 26 | Apr 30 | May 7 | Jul 2 – Aug 27 | 55–70 |
| Snow Peas | Mar 19 | Apr 9 | Apr 23 | Jun 18 – Aug 13 | 50–65 |
| Soybeans | — | Apr 30 | — | Jul 23 – Sep 17 | 80–120 |
| Spaghetti Squash | Mar 19 | Apr 30 | May 7 | Aug 6 – Sep 3 | 85–100 |
| Spinach | Mar 19 | Apr 9 | Apr 23 | May 28 – Jul 30 | 35–50 |
| Squash (Summer) | Mar 19 | Apr 30 | May 7 | Jun 25 – Aug 27 | 45–65 |
| Squash (Winter) | Mar 19 | Apr 30 | May 7 | Jul 30 – Sep 24 | 80–120 |
| Sunchoke | — | — | May 7 | Aug 27 – Oct 22 | 110–150 |
| Sunflower | Feb 26 | Apr 30 | May 7 | Jul 16 – Sep 3 | 70–100 |
| Sweet Corn | — | Apr 30 | — | Jul 2 – Aug 13 | 60–90 |
| Sweet Potatoes | Feb 26 | Apr 30 | May 7 | Aug 6 – Sep 24 | 90–120 |
| Tatsoi | Mar 19 | Apr 9 | Apr 23 | May 28 – Jul 2 | 35–50 |
| Tomatillo | Feb 26 | Apr 30 | May 7 | Jul 9 – Sep 17 | 60–85 |
| Tomatoes | Feb 26 | Apr 30 | May 7 | Jul 9 – Sep 17 | 60–85 |
| Turnip | — | Apr 9 | — | May 21 – Jun 25 | 40–60 |
| Watercress | Mar 19 | Apr 9 | Apr 23 | Jun 4 – Jul 9 | 40–60 |
| Watermelon | Mar 19 | Apr 30 | May 7 | Jul 16 – Sep 3 | 70–100 |
| Wax Beans | — | Apr 30 | — | Jun 25 – Aug 20 | 50–65 |
| Winter Melon | Feb 26 | Apr 30 | May 7 | Aug 6 – Sep 24 | 90–120 |
| Yard Long Beans | Feb 26 | Apr 30 | May 7 | Jul 2 – Aug 13 | 55–80 |
| Zucchini | Mar 19 | Apr 30 | May 7 | Jun 25 – Aug 20 | 45–60 |
🍓 Fruits to Grow in Ada County
27 fruits that grow well in Zone 6b with planting dates for Ada County.
Show all 27 fruits with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Alpine Strawberries | — | — | May 14 | Aug 13 – Nov 26 | 90–180 |
| Aronia | — | — | May 14 | — | 730–1095 |
| Blackberries | — | — | May 14 | — | 365–730 |
| Blueberries | — | — | May 14 | — | 730–1095 |
| Boysenberries | — | — | May 14 | — | 365–730 |
| Cantaloupe | — | — | May 14 | Jul 23 – Aug 27 | 70–90 |
| Che Fruit | — | — | May 14 | — | 1095–1825 |
| Cranberries | — | — | May 14 | — | 730–1095 |
| Currants | — | — | May 14 | — | 730–1095 |
| Elderberries | — | — | May 14 | — | 730–1095 |
| Goji Berries | — | — | May 14 | — | 730–1095 |
| Gooseberries | — | — | May 14 | — | 730–1095 |
| Grapes | — | — | May 14 | — | 730–1095 |
| Ground Cherry | — | — | May 14 | Jul 23 – Sep 17 | 65–80 |
| Hardy Kiwi | — | — | May 14 | — | 1095–1825 |
| Haskaps | — | — | May 14 | — | 730–1095 |
| Honeydew | — | — | May 14 | Aug 6 – Sep 17 | 80–110 |
| Jostaberry | — | — | May 14 | — | 730–1095 |
| Lingonberries | — | — | May 14 | — | 730–1095 |
| Medlar | — | — | May 14 | — | 1095–1825 |
| Mulberries | — | — | May 14 | — | 730–1825 |
| Pawpaw | — | — | May 14 | — | 1095–2555 |
| Persimmon | — | — | May 14 | — | 1095–2555 |
| Quince | — | — | May 14 | — | 1095–1825 |
| Raspberries | — | — | May 14 | — | 365–730 |
| Serviceberries | — | — | May 14 | — | 730–1095 |
| Strawberries | — | — | May 14 | Aug 13 – Nov 26 | 90–365 |
🌿 Herbs to Grow in Ada County
38 herbs that grow well in Zone 6b with planting dates for Ada County.
Show all 38 herbs with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Angelica | Mar 19 | Apr 9 | Apr 16 | — | 365–730 |
| Anise | Mar 19 | Apr 9 | Apr 16 | Jul 16 – Oct 1 | 90–120 |
| Basil | Mar 5 | Apr 30 | May 7 | Jul 2 – Sep 3 | 50–75 |
| Bee Balm | — | — | Apr 30 | Jul 30 – Oct 15 | 90–120 |
| Borage | Mar 19 | Apr 9 | Apr 16 | Jun 11 – Jul 30 | 50–60 |
| Caraway | Mar 19 | Apr 9 | Apr 16 | — | 365–450 |
| Catnip | — | — | Apr 30 | Jul 2 – Sep 3 | 60–80 |
| Chamomile | Mar 19 | Apr 9 | Apr 16 | Jun 18 – Aug 27 | 60–90 |
| Chervil | Mar 19 | Apr 9 | Apr 16 | May 28 – Jul 30 | 40–60 |
| Chives | — | — | Apr 30 | Jul 2 – Sep 10 | 60–90 |
| Cilantro | Mar 19 | Apr 9 | Apr 16 | May 28 – Jul 30 | 40–60 |
| Comfrey | — | — | Apr 30 | Jul 2 – Sep 10 | 60–90 |
| Cumin | Mar 19 | Apr 9 | Apr 16 | Jul 30 – Oct 1 | 100–120 |
| Dill | Mar 19 | Apr 9 | Apr 16 | May 28 – Jul 30 | 40–60 |
| Echinacea | — | — | Apr 30 | Sep 3 – Nov 12 | 120–180 |
| Epazote | Mar 5 | Apr 30 | May 7 | Jun 25 – Aug 20 | 45–60 |
| Fennel (herb) | Mar 19 | Apr 9 | Apr 16 | Jun 18 – Aug 27 | 60–90 |
| Feverfew | — | — | Apr 30 | Jul 30 – Oct 15 | 90–120 |
| Garlic Chives | — | — | Apr 30 | Jul 2 – Sep 10 | 60–90 |
| Horehound | — | — | Apr 30 | Jul 16 – Sep 10 | 75–90 |
| Hyssop | — | — | Apr 30 | Jul 9 – Sep 10 | 70–90 |
| Lavender | — | — | Apr 30 | Jul 30 – Nov 12 | 90–200 |
| Lemon Balm | — | — | Apr 30 | Jul 2 – Aug 20 | 60–70 |
| Lemon Thyme | — | — | Apr 30 | Jul 9 – Sep 10 | 70–90 |
| Lovage | — | — | Apr 30 | Jul 9 – Sep 10 | 70–90 |
| Marjoram | — | — | Apr 30 | Jul 2 – Sep 10 | 60–90 |
| Mint | — | — | Apr 30 | Jul 2 – Sep 10 | 60–90 |
| Oregano | — | — | Apr 30 | Jul 2 – Sep 10 | 60–90 |
| Parsley | Mar 19 | Apr 9 | Apr 16 | Jun 18 – Aug 20 | 60–80 |
| Rue | — | — | Apr 30 | Jul 9 – Sep 10 | 70–90 |
| Sage | — | — | Apr 30 | Jul 16 – Sep 10 | 75–90 |
| Savory | — | — | Apr 30 | Jun 25 – Aug 20 | 50–70 |
| Sorrel | Mar 19 | Apr 9 | Apr 16 | May 28 – Jul 30 | 40–60 |
| Tarragon | — | — | Apr 30 | Jul 2 – Sep 10 | 60–90 |
| Thai Basil | Mar 5 | Apr 30 | May 7 | Jul 2 – Sep 3 | 50–75 |
| Thyme | — | — | Apr 30 | Jul 9 – Sep 10 | 70–90 |
| Valerian | — | — | Apr 30 | Sep 3 – Nov 12 | 120–180 |
| Yarrow | — | — | Apr 30 | Jul 30 – Oct 15 | 90–120 |
Monthly Planting Guide for Ada County
Gardening Guides & Resources
Helpful guides from The Ultimate Homestead to improve your garden in Ada County.
Frequently Asked Questions
What planting zone is Ada County, ID?
Ada County is in USDA Hardiness Zone 6b. 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 Ada County, ID?
Based on 31 years of NOAA weather station data, the median last spring frost in Ada County falls around April 23. In 8 out of 10 years, last frost lands between March 30 and May 13 — a 43-day window of variability. Use May 13 as your conservative safe-to-plant date for frost-sensitive crops.
When is the first fall frost in Ada County, ID?
The median first fall frost in Ada County arrives around October 16. In cold years it can arrive as early as September 30; in mild years as late as November 3. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.
How long is the growing season in Ada County?
Ada County has a frost-free growing season of approximately 176 days. This is enough time for most warm-season crops including tomatoes, peppers, and squash with proper timing. Climate records show the growing season is trending longer by about 5.02 days per decade.
What is the soil like in Ada County for gardening?
Ada County has predominantly Loam soil with a pH range of 6.4–7.7 and Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.
What is grown commercially in Ada County?
Ada County has commercial agriculture that includes Potatoes, Hay, Wheat, Cattle, Dairy. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.
Is Ada County a good location for home gardening?
Ada County scores 34/100 (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 Ada County gardeners in Zone 6b 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.
