Grant County, OR — Planting Guide
Grant County is in USDA Zone 5b. The average last spring frost is June 6 and the first fall frost is September 10, giving you a growing season of approximately 96 days.
At an elevation of 2,838 ft, Grant County receives approximately 22.6 in of rainfall annually. Summer highs average 83°F with winter lows around 11°F. The predominant soil type is Silt Loam.
Based on 31 years of NOAA climate station data, the last frost date here varies by 50 days year to year — ranging from May 6 in warm years to June 26 in cold years. The growing season is trending longer by about 5.85 days per decade. Grant County scores 53/100 (Moderate) on the Microclimate Index.
🌡️ Zone
5b (-15°F to -10°F min)
❄️ Last Frost
June 6
🍂 First Frost
September 10
📅 Growing Season
96 days
⛰️ Elevation
2,838 ft
🌧️ Annual Rainfall
22.6 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 | 3.2 in | 16 days | — | None |
| Feb | 2.9 in | 14 days | — | None |
| Mar | 2.3 in | 17 days | — | None |
| Apr | 1.5 in | 11 days | 2.8 in | High |
| May | 1.3 in | 10 days | 3 in | High |
| Jun | 0.8 in | 7 days | 3.5 in | Critical |
| Jul | 0.4 in | 3 days | 3.9 in | Critical |
| Aug | 0.4 in | 2 days | 3.9 in | Critical |
| Sep | 0.9 in | 4 days | 3.4 in | Critical |
| Oct | 1.8 in | 11 days | 2.5 in | High |
| Nov | 3.1 in | 18 days | — | None |
| Dec | 3.9 in | 18 days | — | None |
Annual total: 22.5 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.
Grant County Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.4
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 26 | Oct 4 | 100 days |
| Cautious | Jun 19 | Sep 20 | 93 days |
| Average year | Jun 6 | Sep 10 | 96 days |
| Optimistic | May 20 | Aug 16 | 88 days |
| Aggressive (risky) | May 6 | Aug 4 | 90 days |
Not very — frost dates can vary by ±50 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 5.9 days per decade). Spring is arriving earlier than it used to. Good news for gardeners.
Gardening Difficulty Score
Grant County presents some gardening challenges. Choose adapted varieties and plan around frost dates.
Local Gardening Help in Grant 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 Grant County's climate and soil.
County Extension Office
Grant County Oregon State University Extension Extension Office
Phone: 541-737-2713
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 Grant County
Finding local nurseries & garden centers in Grant County
Why Buy Local
Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Grant 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 Grant County OR" or "garden center Grant 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 Grant County OR" or check your extension office and local parks department. Facebook groups like "Grant County Gardeners" or "Oregon 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
15.3 hours
Summer solstice daylight
Shortest Day
8.7 hours
Winter solstice daylight
Peak Sun Hours
10 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 | 2.2 hr | Short day |
| February | 10.2 hr | 3 hr | Short day |
| March | 11.6 hr | 4.2 hr | Short day |
| April | 13.2 hr | 5.5 hr | Neutral |
| May | 14.6 hr | 7.3 hr | Long day |
| June | 15.3 hr | 8.6 hr | Long day |
| July | 15 hr | 10 hr | Long day |
| August | 13.9 hr | 9 hr | Neutral |
| September | 12.3 hr | 7 hr | Neutral |
| October | 10.7 hr | 4.1 hr | Short day |
| November | 9.3 hr | 2.2 hr | Short day |
| December | 8.7 hr | 2 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
5 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 | 15°F | 24°F | ❄️ Dormant | ~36 weeks |
| Feb | 19°F | 23°F | ❄️ Dormant | ~36 weeks |
| Mar | 25°F | 29°F | ❄️ Dormant | ~36 weeks |
| Apr | 37°F | 36°F | ❄️ Dormant | ~36 weeks |
| May | 51°F | 49°F | ♻️ Active | ~14 weeks |
| Jun | 61°F | 58°F | ♻️ Active | ~14 weeks |
| Jul | 70°F | 64°F | 🔥 Peak | ~8 weeks |
| Aug | 71°F | 66°F | 🔥 Peak | ~8 weeks |
| Sep | 64°F | 62°F | ♻️ Active | ~14 weeks |
| Oct | 49°F | 54°F | 🐢 Slow | ~24 weeks |
| Nov | 34°F | 43°F | ❄️ Dormant | ~36 weeks |
| Dec | 24°F | 31°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 Grant 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 |
| Japanese beetles | Moderate | Jun, Jul, Aug |
| Squash bugs | Low | Jun, Jul, Aug |
| Tomato hornworms | Moderate | Jul, Aug |
| Cabbage loopers | Low | May, Jun, Jul, Aug |
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 Grant County
Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with county-specific planting dates.
Fall Cover Crops (6 options) — Plant after harvest to protect soil over winter
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Austrian winter peas | Jul 6 | May 23 | ✓ Yes | Fixes nitrogen, good for heavy clay soils |
| Daikon radish | Jul 22 | May 23 | — | Deep taproot breaks compaction, excellent for clay soils |
| Hairy vetch | Jun 28 | May 16 | ✓ Yes | Excellent nitrogen fixer, good for depleted soils |
| Oats | Jul 31 | May 16 | — | Quick biomass, winterkills in cold zones — no spring tillage needed |
| Winter rye | Jun 10 | May 23 | — | Suppresses weeds, prevents erosion, breaks up compacted soil |
| Winter wheat | Jun 1 | May 23 | — | 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 | Jun 15 | Jul 16 | — | Rapid growth, attracts pollinators, suppresses weeds |
| Sorghum-sudan grass | Jun 16 | Jul 9 | — | Massive biomass, breaks compaction, suppresses nematodes |
| White clover | May 8 | Jul 9 | ✓ 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 1 | Aug 13 | — | 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: 10 mph Summer: 8 mph
Fall: 10 mph Winter: 11 mph
Prevailing wind: SW. Moderate wind — consider a temporary windbreak for young seedlings.
Windbreak Benefit
4.9/10
Moderately beneficial — a simple fence or trellis can protect delicate crops from wind stress.
Frost Pocket Risk
Moderate
Some terrain variation (785 ft range). Garden on slopes or higher ground if possible to avoid late-season frost pockets.
Rainwater Harvesting Potential
How much water you can collect, when to collect it, and what size system you need for your garden.
Annual Collection
11,214 gal
Per 1,000 sq ft of roof area (at 80% collection efficiency)
Recommended Setup
7 rain barrels (55 gal each)
For a typical 500 sq ft garden. Serious collectors: consider a 2,250 gal tank.
Legal Status
Unrestricted
Rainwater harvesting is fully legal in your state with no restrictions.
Best Collection Months
Jan, Feb, Nov, Dec
Highest rainfall months — your barrels will fill up quickly during these months.
Months to Draw From Storage
Jun, Jul, Aug, Sep
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 22.5 inches of rain per year
- A 1,000 sq ft roof can collect roughly 11,214 gallons annually
- Rainwater harvesting is fully legal in your state
- Stock up on stored water before your dry season (Jun, Jul, Aug)
- Use a first-flush diverter to keep roof debris out of your collection
Soil & Growing Conditions in Grant County
Soil Type
Silt Loam
Soil pH 5.4–6.4 · Excessively Drained drainage
Native soil is well-suited to most vegetables and herbs with regular compost additions.
Watering Needs
Drought stress: 1.5/10
Grant County has very low drought pressure. Natural rainfall usually meets garden needs — water only during extended dry spells.
Season Tips
96-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 Grant County
106 vegetables that grow well in Zone 5b with planting dates for Grant County.
Show all 106 vegetables with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Acorn Squash | May 2 | Jun 13 | Jun 20 | Sep 12 – Oct 17 | 80–100 |
| Amaranth | Apr 11 | Jun 13 | Jun 20 | Sep 19 – Nov 7 | 90–120 |
| Arugula | May 2 | May 23 | Jun 6 | Jul 11 – Sep 12 | 30–50 |
| Asparagus | — | — | Jun 20 | — | 730–1095 |
| Beets | — | May 23 | — | Jul 18 – Aug 15 | 50–70 |
| Belgian Endive | May 2 | May 23 | Jun 6 | Sep 26 – Nov 21 | 110–150 |
| Bitter Melon | Apr 11 | Jun 13 | Jun 20 | Aug 22 – Oct 3 | 60–90 |
| Black Beans | — | Jun 13 | — | Sep 12 – Oct 31 | 90–120 |
| Bok Choy | May 2 | May 23 | Jun 6 | Jul 18 – Aug 22 | 40–60 |
| Broccoli | May 2 | May 23 | Jun 6 | Aug 8 – Sep 19 | 60–90 |
| Broccoli Rabe | May 2 | May 23 | Jun 6 | Jul 18 – Aug 22 | 40–60 |
| Brussels Sprouts | May 2 | May 23 | Jun 6 | Sep 5 – Oct 31 | 90–130 |
| Butternut Squash | May 2 | Jun 13 | Jun 20 | Sep 19 – Oct 24 | 85–110 |
| Cabbage | May 2 | May 23 | Jun 6 | Aug 8 – Oct 3 | 60–100 |
| Calabash | Apr 11 | Jun 13 | Jun 20 | Sep 12 – Nov 7 | 80–120 |
| Carrots | — | May 23 | — | Jul 25 – Aug 29 | 60–80 |
| Cauliflower | May 2 | May 23 | Jun 6 | Aug 1 – Oct 3 | 55–100 |
| Celeriac | May 2 | May 23 | Jun 6 | Sep 19 – Oct 24 | 100–120 |
| Celery | May 2 | May 23 | Jun 6 | Aug 29 – Oct 24 | 80–120 |
| Celtuce | May 2 | May 23 | Jun 6 | Aug 8 – Sep 19 | 60–90 |
| Chard | May 2 | May 23 | Jun 6 | Aug 1 – Sep 19 | 50–60 |
| Chickpeas | May 2 | May 23 | Jun 6 | Aug 29 – Oct 10 | 80–110 |
| Chicory | May 2 | May 23 | Jun 6 | Aug 8 – Sep 19 | 60–85 |
| Chinese Cabbage | May 2 | May 23 | Jun 6 | Aug 1 – Aug 29 | 50–70 |
| Christmas Lima Beans | Apr 11 | Jun 13 | Jun 20 | Sep 12 – Oct 17 | 80–100 |
| Collard Greens | May 2 | May 23 | Jun 6 | Aug 1 – Oct 3 | 55–75 |
| Corn | — | Jun 13 | — | Aug 15 – Oct 10 | 60–100 |
| Cowpeas | — | Jun 13 | — | Aug 15 – Sep 26 | 60–90 |
| Cress | May 2 | May 23 | Jun 6 | Jun 20 – Jul 11 | 14–21 |
| Crookneck Squash | May 2 | Jun 13 | Jun 20 | Aug 8 – Sep 5 | 45–60 |
| Crosne | — | May 23 | — | Oct 24 – Nov 7 | 150–200 |
| Cucumber | May 2 | Jun 13 | Jun 20 | Aug 15 – Oct 10 | 50–70 |
| Daikon | — | May 23 | — | Jul 18 – Aug 15 | 50–70 |
| Delicata Squash | May 2 | Jun 13 | Jun 20 | Sep 12 – Oct 17 | 80–100 |
| Edamame | — | Jun 13 | — | Aug 29 – Oct 10 | 75–100 |
| Eggplant | Mar 28 | Jun 13 | Jun 20 | Aug 29 – Oct 31 | 65–85 |
| Endive | May 2 | May 23 | Jun 6 | Jul 25 – Aug 29 | 45–65 |
| Escarole | May 2 | May 23 | Jun 6 | Aug 1 – Aug 29 | 50–70 |
| Fava Beans | May 2 | May 23 | Jun 6 | Aug 22 – Oct 3 | 75–100 |
| Fennel | Apr 11 | Jun 13 | Jun 20 | Aug 22 – Oct 3 | 60–90 |
| Garlic | — | — | — | — | 90–240 |
| Green Beans | — | Jun 13 | — | Aug 8 – Oct 3 | 50–65 |
| Horseradish | — | — | Jun 20 | Oct 24 – Dec 5 | 120–180 |
| Hot Peppers | Mar 28 | Jun 13 | Jun 20 | Aug 29 – Dec 5 | 70–120 |
| Hubbard Squash | May 2 | Jun 13 | Jun 20 | Oct 3 – Nov 7 | 100–120 |
| Kabocha | May 2 | Jun 13 | Jun 20 | Sep 19 – Oct 17 | 85–100 |
| Kai Lan | May 2 | May 23 | Jun 6 | Jul 25 – Aug 22 | 45–60 |
| Kale | May 2 | May 23 | Jun 6 | Aug 1 – Sep 26 | 50–70 |
| Kidney Beans | — | Jun 13 | — | Sep 12 – Oct 17 | 85–110 |
| Kohlrabi | May 2 | May 23 | Jun 6 | Jul 25 – Aug 29 | 45–65 |
| Komatsuna | May 2 | May 23 | Jun 6 | Jul 11 – Aug 15 | 35–50 |
| Leeks | May 2 | May 23 | Jun 6 | Sep 5 – Nov 21 | 90–150 |
| Lentils | May 2 | May 23 | Jun 6 | Aug 29 – Oct 10 | 80–110 |
| Lettuce | May 2 | May 23 | Jun 6 | Jul 11 – Sep 19 | 30–60 |
| Lima Beans | — | Jun 13 | — | Aug 15 – Sep 26 | 60–90 |
| Mache | May 2 | May 23 | Jun 6 | Jul 18 – Aug 22 | 40–60 |
| Melon | May 2 | Jun 13 | Jun 20 | Aug 29 – Oct 17 | 70–100 |
| Microgreens | May 2 | May 23 | Jun 6 | Jun 13 – Jul 11 | 7–21 |
| Mitsuba | May 2 | May 23 | May 30 | Jul 25 – Sep 19 | 50–70 |
| Mizuna | May 2 | May 23 | Jun 6 | Jul 11 – Aug 8 | 30–45 |
| Mustard Greens | May 2 | May 23 | Jun 6 | Jul 11 – Sep 12 | 30–50 |
| Napa Cabbage | May 2 | May 23 | Jun 6 | Aug 1 – Sep 5 | 55–75 |
| New Zealand Spinach | Apr 11 | Jun 13 | Jun 20 | Aug 15 – Sep 12 | 55–70 |
| Okra | Apr 11 | Jun 13 | Jun 20 | Aug 15 – Oct 10 | 50–65 |
| Onion | May 2 | May 23 | Jun 6 | Sep 5 – Oct 24 | 90–120 |
| Pac Choi | May 2 | May 23 | Jun 6 | Jul 18 – Aug 15 | 40–55 |
| Parsnip | — | May 23 | — | Sep 5 – Oct 17 | 100–130 |
| Patty Pan Squash | May 2 | Jun 13 | Jun 20 | Aug 8 – Sep 5 | 45–60 |
| Peas | May 2 | May 23 | Jun 6 | Aug 1 – Sep 26 | 55–70 |
| Peppers | Mar 28 | Jun 13 | Jun 20 | Aug 22 – Oct 31 | 60–90 |
| Pole Beans | Apr 11 | Jun 13 | Jun 20 | Aug 15 – Oct 10 | 55–70 |
| Potatoes | Apr 11 | Jun 13 | Jun 20 | Aug 29 – Nov 7 | 70–120 |
| Pumpkin | May 2 | Jun 13 | Jun 20 | Sep 19 – Nov 7 | 85–120 |
| Purslane | May 2 | May 23 | Jun 6 | Jul 18 – Aug 22 | 40–60 |
| Radicchio | May 2 | May 23 | Jun 6 | Aug 8 – Sep 12 | 60–80 |
| Radish | — | May 23 | — | Jun 20 – Jul 11 | 22–35 |
| Rhubarb | — | — | Jun 27 | — | 365–730 |
| Romanesco | May 2 | May 23 | Jun 6 | Aug 22 – Oct 3 | 75–100 |
| Rutabaga | — | May 23 | — | Aug 15 – Sep 19 | 80–100 |
| Salsify | — | May 23 | — | Sep 5 – Oct 17 | 100–130 |
| Savoy Cabbage | May 2 | May 23 | Jun 6 | Aug 15 – Oct 10 | 70–110 |
| Scallions | May 2 | May 23 | Jun 6 | Aug 1 – Aug 29 | 50–70 |
| Scarlet Runner Beans | Apr 11 | Jun 13 | Jun 20 | Aug 22 – Sep 26 | 60–80 |
| Shallot | May 2 | May 23 | Jun 6 | Sep 5 – Oct 24 | 90–120 |
| Shiso | Apr 18 | Jun 13 | Jun 20 | Aug 15 – Oct 10 | 50–70 |
| Snap Peas | Apr 11 | Jun 13 | Jun 20 | Aug 15 – Oct 10 | 55–70 |
| Snow Peas | May 2 | May 23 | Jun 6 | Aug 1 – Sep 26 | 50–65 |
| Soybeans | — | Jun 13 | — | Sep 5 – Oct 31 | 80–120 |
| Spaghetti Squash | May 2 | Jun 13 | Jun 20 | Sep 19 – Oct 17 | 85–100 |
| Spinach | May 2 | May 23 | Jun 6 | Jul 11 – Sep 12 | 35–50 |
| Squash (Summer) | May 2 | Jun 13 | Jun 20 | Aug 8 – Oct 10 | 45–65 |
| Squash (Winter) | May 2 | Jun 13 | Jun 20 | Sep 12 – Nov 7 | 80–120 |
| Sunchoke | — | — | Jun 20 | Oct 10 – Dec 5 | 110–150 |
| Sunflower | Apr 11 | Jun 13 | Jun 20 | Aug 29 – Oct 17 | 70–100 |
| Sweet Corn | — | Jun 13 | — | Aug 15 – Sep 26 | 60–90 |
| Sweet Potatoes | Apr 11 | Jun 13 | Jun 20 | Sep 19 – Nov 7 | 90–120 |
| Tatsoi | May 2 | May 23 | Jun 6 | Jul 11 – Aug 15 | 35–50 |
| Tomatillo | Apr 11 | Jun 13 | Jun 20 | Aug 22 – Oct 31 | 60–85 |
| Tomatoes | Apr 11 | Jun 13 | Jun 20 | Aug 22 – Oct 31 | 60–85 |
| Turnip | — | May 23 | — | Jul 4 – Aug 8 | 40–60 |
| Watercress | May 2 | May 23 | Jun 6 | Jul 18 – Aug 22 | 40–60 |
| Watermelon | May 2 | Jun 13 | Jun 20 | Aug 29 – Oct 17 | 70–100 |
| Wax Beans | — | Jun 13 | — | Aug 8 – Oct 3 | 50–65 |
| Winter Melon | Apr 11 | Jun 13 | Jun 20 | Sep 19 – Nov 7 | 90–120 |
| Yard Long Beans | Apr 11 | Jun 13 | Jun 20 | Aug 15 – Sep 26 | 55–80 |
| Zucchini | May 2 | Jun 13 | Jun 20 | Aug 8 – Oct 3 | 45–60 |
🍓 Fruits to Grow in Grant County
27 fruits that grow well in Zone 5b with planting dates for Grant County.
Show all 27 fruits with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Alpine Strawberries | — | — | Jun 27 | Sep 26 – Dec 12 | 90–180 |
| Aronia | — | — | Jun 27 | — | 730–1095 |
| Blackberries | — | — | Jun 27 | — | 365–730 |
| Blueberries | — | — | Jun 27 | — | 730–1095 |
| Boysenberries | — | — | Jun 27 | — | 365–730 |
| Cantaloupe | — | — | Jun 27 | Sep 5 – Oct 10 | 70–90 |
| Che Fruit | — | — | Jun 27 | — | 1095–1825 |
| Cranberries | — | — | Jun 27 | — | 730–1095 |
| Currants | — | — | Jun 27 | — | 730–1095 |
| Elderberries | — | — | Jun 27 | — | 730–1095 |
| Goji Berries | — | — | Jun 27 | — | 730–1095 |
| Gooseberries | — | — | Jun 27 | — | 730–1095 |
| Grapes | — | — | Jun 27 | — | 730–1095 |
| Ground Cherry | — | — | Jun 27 | Sep 5 – Oct 31 | 65–80 |
| Hardy Kiwi | — | — | Jun 27 | — | 1095–1825 |
| Haskaps | — | — | Jun 27 | — | 730–1095 |
| Honeydew | — | — | Jun 27 | Sep 19 – Oct 31 | 80–110 |
| Jostaberry | — | — | Jun 27 | — | 730–1095 |
| Lingonberries | — | — | Jun 27 | — | 730–1095 |
| Medlar | — | — | Jun 27 | — | 1095–1825 |
| Mulberries | — | — | Jun 27 | — | 730–1825 |
| Pawpaw | — | — | Jun 27 | — | 1095–2555 |
| Persimmon | — | — | Jun 27 | — | 1095–2555 |
| Quince | — | — | Jun 27 | — | 1095–1825 |
| Raspberries | — | — | Jun 27 | — | 365–730 |
| Serviceberries | — | — | Jun 27 | — | 730–1095 |
| Strawberries | — | — | Jun 27 | Sep 26 – Dec 12 | 90–365 |
🌿 Herbs to Grow in Grant County
37 herbs that grow well in Zone 5b with planting dates for Grant County.
Show all 37 herbs with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Angelica | May 2 | May 23 | May 30 | — | 365–730 |
| Anise | May 2 | May 23 | May 30 | Aug 29 – Nov 14 | 90–120 |
| Basil | Apr 18 | Jun 13 | Jun 20 | Aug 15 – Oct 17 | 50–75 |
| Bee Balm | — | — | Jun 13 | Sep 12 – Nov 28 | 90–120 |
| Borage | May 2 | May 23 | May 30 | Jul 25 – Sep 12 | 50–60 |
| Caraway | May 2 | May 23 | May 30 | — | 365–450 |
| Catnip | — | — | Jun 13 | Aug 15 – Oct 17 | 60–80 |
| Chamomile | May 2 | May 23 | May 30 | Aug 1 – Oct 10 | 60–90 |
| Chervil | May 2 | May 23 | May 30 | Jul 11 – Sep 12 | 40–60 |
| Chives | — | — | Jun 13 | Aug 15 – Oct 24 | 60–90 |
| Cilantro | May 2 | May 23 | May 30 | Jul 11 – Sep 12 | 40–60 |
| Comfrey | — | — | Jun 13 | Aug 15 – Oct 24 | 60–90 |
| Cumin | May 2 | May 23 | May 30 | Sep 12 – Nov 14 | 100–120 |
| Dill | May 2 | May 23 | May 30 | Jul 11 – Sep 12 | 40–60 |
| Echinacea | — | — | Jun 13 | Oct 17 – Nov 28 | 120–180 |
| Epazote | Apr 18 | Jun 13 | Jun 20 | Aug 8 – Oct 3 | 45–60 |
| Fennel (herb) | May 2 | May 23 | May 30 | Aug 1 – Oct 10 | 60–90 |
| Feverfew | — | — | Jun 13 | Sep 12 – Nov 28 | 90–120 |
| Garlic Chives | — | — | Jun 13 | Aug 15 – Oct 24 | 60–90 |
| Horehound | — | — | Jun 13 | Aug 29 – Oct 24 | 75–90 |
| Hyssop | — | — | Jun 13 | Aug 22 – Oct 24 | 70–90 |
| Lavender | — | — | Jun 13 | Sep 12 – Nov 28 | 90–200 |
| Lemon Balm | — | — | Jun 13 | Aug 15 – Oct 3 | 60–70 |
| Lemon Thyme | — | — | Jun 13 | Aug 22 – Oct 24 | 70–90 |
| Lovage | — | — | Jun 13 | Aug 22 – Oct 24 | 70–90 |
| Mint | — | — | Jun 13 | Aug 15 – Oct 24 | 60–90 |
| Oregano | — | — | Jun 13 | Aug 15 – Oct 24 | 60–90 |
| Parsley | May 2 | May 23 | May 30 | Aug 1 – Oct 3 | 60–80 |
| Rue | — | — | Jun 13 | Aug 22 – Oct 24 | 70–90 |
| Sage | — | — | Jun 13 | Aug 29 – Oct 24 | 75–90 |
| Savory | — | — | Jun 13 | Aug 8 – Oct 3 | 50–70 |
| Sorrel | May 2 | May 23 | May 30 | Jul 11 – Sep 12 | 40–60 |
| Tarragon | — | — | Jun 13 | Aug 15 – Oct 24 | 60–90 |
| Thai Basil | Apr 18 | Jun 13 | Jun 20 | Aug 15 – Oct 17 | 50–75 |
| Thyme | — | — | Jun 13 | Aug 22 – Oct 24 | 70–90 |
| Valerian | — | — | Jun 13 | Oct 17 – Nov 28 | 120–180 |
| Yarrow | — | — | Jun 13 | Sep 12 – Nov 28 | 90–120 |
Monthly Planting Guide for Grant County
Gardening Guides & Resources
Helpful guides from The Ultimate Homestead to improve your garden in Grant County.
Frequently Asked Questions
What planting zone is Grant County, OR?
Grant County is in USDA Hardiness Zone 5b. 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 Grant County, OR?
Based on 31 years of NOAA weather station data, the median last spring frost in Grant County falls around June 6. In 8 out of 10 years, last frost lands between May 6 and June 26 — a 50-day window of variability. Use June 26 as your conservative safe-to-plant date for frost-sensitive crops.
When is the first fall frost in Grant County, OR?
The median first fall frost in Grant County arrives around September 10. In cold years it can arrive as early as August 4; in mild years as late as October 4. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.
How long is the growing season in Grant County?
Grant County has a frost-free growing season of approximately 96 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 5.85 days per decade.
What is the soil like in Grant County for gardening?
Grant County has predominantly Silt Loam soil with a pH range of 5.4–6.4 and Excessively Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.
What is grown commercially in Grant County?
Grant County has commercial agriculture that includes Wheat, Potatoes, Apples, Cattle, Hops. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.
Is Grant County a good location for home gardening?
Grant County scores 53/100 (Moderate) on our Microclimate Index, which combines frost reliability, drought pressure, soil challenge, elevation risk, and long-term climate trend. Conditions here are moderate — most common crops grow well with standard timing and care.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Grant County gardeners in Zone 5b 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.
