Benton County, WA — Planting Guide
Benton County is in USDA Zone 7a. The average last spring frost is April 3 and the first fall frost is October 27, giving you a growing season of approximately 207 days.
At an elevation of 2,633 ft, Benton County receives approximately 22.5 in of rainfall annually. Summer highs average 88°F with winter lows around 32°F. The predominant soil type is Silt Loam.
Based on 31 years of NOAA climate station data, the last frost date here varies by 36 days year to year — ranging from March 14 in warm years to April 20 in cold years. The growing season is trending longer by about 2.56 days per decade. Benton County scores 50/100 (Moderate) on the Microclimate Index.
🌡️ Zone
7a (0°F to 5°F min)
❄️ Last Frost
April 3
🍂 First Frost
October 27
📅 Growing Season
207 days
⛰️ Elevation
2,633 ft
🌧️ Annual Rainfall
22.5 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 | 3.2 in | 16 days | — | None |
| Feb | 2.6 in | 13 days | — | None |
| Mar | 2.1 in | 16 days | 2.2 in | High |
| Apr | 1.5 in | 12 days | 2.8 in | High |
| May | 1.4 in | 10 days | 2.9 in | High |
| Jun | 0.9 in | 7 days | 3.4 in | Critical |
| Jul | 0.4 in | 3 days | 3.9 in | Critical |
| Aug | 0.4 in | 3 days | 3.9 in | Critical |
| Sep | 0.8 in | 5 days | 3.5 in | Critical |
| Oct | 2 in | 12 days | 2.3 in | High |
| Nov | 3.7 in | 18 days | — | None |
| Dec | 3.5 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.
Benton County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.3
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) | Apr 20 | Nov 10 | 204 days |
| Cautious | Apr 11 | Nov 1 | 204 days |
| Average year | Apr 3 | Oct 27 | 207 days |
| Optimistic | Mar 24 | Oct 22 | 212 days |
| Aggressive (risky) | Mar 14 | Oct 9 | 209 days |
Not very — frost dates can vary by ±36 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 2.6 days per decade). Spring is arriving earlier than it used to. Good news for gardeners.
Gardening Difficulty Score
Benton County presents some gardening challenges. Choose adapted varieties and plan around frost dates.
Local Gardening Help in Benton 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 Benton County's climate and soil.
County Extension Office
Benton County Washington State University Extension Extension Office
Phone: 509-335-2811
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 Benton County
Finding local nurseries & garden centers in Benton County
Why Buy Local
Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Benton 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 Benton County WA" or "garden center Benton 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 Benton County WA" or check your extension office and local parks department. Facebook groups like "Benton County Gardeners" or "Washington 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
15.6 hours
Summer solstice daylight
Shortest Day
8.4 hours
Winter solstice daylight
Peak Sun Hours
10.4 hr/day peak (summer)
Peak sun hours (green dashed line below) account for cloud cover — this is the usable direct sunlight your garden actually receives. Most vegetables need 6+ peak sun hours.
Onion tip: Your long summer days (14+ hours) support long-day onion varieties like Walla Walla, Sweet Spanish, and Ailsa Craig.
View detailed monthly data
| Month | Daylight Hours | Peak Sun Hours | Day Length |
|---|---|---|---|
| January | 8.8 hr | 2.2 hr | Short day |
| February | 10.1 hr | 3 hr | Short day |
| March | 11.6 hr | 4.1 hr | Short day |
| April | 13.3 hr | 5.5 hr | Neutral |
| May | 14.8 hr | 7.2 hr | Long day |
| June | 15.6 hr | 8.7 hr | Long day |
| July | 15.2 hr | 10.4 hr | Long day |
| August | 14 hr | 9.4 hr | Long day |
| September | 12.3 hr | 7.2 hr | Neutral |
| October | 10.6 hr | 4 hr | Short day |
| November | 9.2 hr | 2.3 hr | Short day |
| December | 8.4 hr | 1.9 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 warm enough from May through Oct.
Best Month to Compost
Jun
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 | 31°F | 38°F | ❄️ Dormant | ~36 weeks |
| Feb | 32°F | 37°F | ❄️ Dormant | ~36 weeks |
| Mar | 38°F | 42°F | ❄️ Dormant | ~36 weeks |
| Apr | 49°F | 49°F | 🐢 Slow | ~24 weeks |
| May | 62°F | 58°F | ♻️ Active | ~14 weeks |
| Jun | 71°F | 67°F | 🔥 Peak | ~8 weeks |
| Jul | 79°F | 73°F | 🔥 Peak | ~8 weeks |
| Aug | 80°F | 76°F | 🔥 Peak | ~8 weeks |
| Sep | 72°F | 73°F | 🔥 Peak | ~8 weeks |
| Oct | 63°F | 65°F | ♻️ Active | ~14 weeks |
| Nov | 50°F | 55°F | 🐢 Slow | ~24 weeks |
| Dec | 37°F | 45°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 Benton 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 | Mar, Apr, May, Jun, Jul, Aug, Sep, Oct |
| Japanese beetles | Moderate | Jun, Jul, Aug |
| Squash vine borers | Moderate | May, Jun, Jul |
| Stink bugs | High | May, Jun, Jul, Aug, Sep |
| Whiteflies | Low | Jun, Jul, Aug, Sep |
| Spider mites | Moderate | Jul, Aug |
Organic pest management tips
- Use row covers on susceptible crops during peak pest months
- Apply neem oil preventatively every 7-14 days during active pest season
- Interplant with strong-scented herbs (basil, marigold) to confuse pests
- Hand-pick larger pests (beetles, caterpillars) in early morning when they're sluggish
- Practice crop rotation — never plant the same family in the same spot within 3 years
Cover Crops for Benton 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 20 | Mar 13 | ✓ Yes | Fixes nitrogen, good for heavy clay soils |
| Crimson clover | Aug 18 | Mar 13 | ✓ Yes | Fixes nitrogen, attracts pollinators in spring |
| Daikon radish | Sep 3 | Mar 13 | — | Deep taproot breaks compaction, excellent for clay soils |
| Hairy vetch | Aug 16 | Mar 20 | ✓ Yes | Excellent nitrogen fixer, good for depleted soils |
| Oats | Sep 17 | Mar 20 | — | Quick biomass, winterkills in cold zones — no spring tillage needed |
| Winter rye | Jul 22 | Mar 13 | — | Suppresses weeds, prevents erosion, breaks up compacted soil |
| Winter wheat | Jul 26 | Mar 13 | — | Erosion control, weed suppression, good biomass |
Spring Cover Crops (4 options) — Build soil before the main growing season
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Buckwheat | Apr 11 | Aug 18 | — | Rapid growth, attracts pollinators, suppresses weeds |
| Cowpeas (southern peas) | Apr 16 | Sep 1 | ✓ Yes | Excellent nitrogen fixer for warm climates, edible |
| Sorghum-sudan grass | Apr 14 | Aug 18 | — | Massive biomass, breaks compaction, suppresses nematodes |
| White clover | Mar 9 | Sep 1 | ✓ 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 | Apr 30 | Oct 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: 10 mph
Prevailing wind: SW. Moderate wind — consider a temporary windbreak for young seedlings.
Windbreak Benefit
4.7/10
Moderately beneficial — a simple fence or trellis can protect delicate crops from wind stress.
Frost Pocket Risk
Moderate
Some terrain variation (695 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 Benton County
Soil Type
Silt Loam
Soil pH 5.5–6.3 · Well Drained drainage
Good candidate for raised beds to maximise drainage and extend the season.
Watering Needs
Drought stress: 3.5/10
Low-to-moderate drought stress. Plan to water 1–2 times per week during peak summer. (22.5 in. annual rainfall)
Season Tips
207-day frost-free season
Plenty of time for warm-season crops. Start heat-lovers indoors 6–8 weeks before last frost to maximise your harvest window.
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 Benton County
113 vegetables that grow well in Zone 7a with planting dates for Benton County.
Show all 113 vegetables with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Acorn Squash | Mar 6 | Apr 10 | Apr 17 | Jul 10 – Aug 14 | 80–100 |
| Amaranth | Feb 13 | Apr 10 | Apr 17 | Jul 17 – Sep 4 | 90–120 |
| Artichoke | — | — | Apr 17 | Aug 21 – Oct 30 | 120–180 |
| Arugula | Feb 27 | Mar 20 | Apr 3 | May 8 – Jul 10 | 30–50 |
| Asparagus | — | — | Apr 17 | — | 730–1095 |
| Beets | — | Mar 20 | — | May 15 – Jun 12 | 50–70 |
| Belgian Endive | Feb 27 | Mar 20 | Apr 3 | Jul 24 – Sep 18 | 110–150 |
| Bitter Melon | Feb 13 | Apr 10 | Apr 17 | Jun 19 – Jul 31 | 60–90 |
| Black Beans | — | Apr 10 | — | Jul 10 – Aug 28 | 90–120 |
| Bok Choy | Feb 27 | Mar 20 | Apr 3 | May 15 – Jun 19 | 40–60 |
| Broccoli | Feb 27 | Mar 20 | Apr 3 | Jun 5 – Jul 17 | 60–90 |
| Broccoli Rabe | Feb 27 | Mar 20 | Apr 3 | May 15 – Jun 19 | 40–60 |
| Brussels Sprouts | Feb 27 | Mar 20 | Apr 3 | Jul 3 – Aug 28 | 90–130 |
| Butternut Squash | Mar 6 | Apr 10 | Apr 17 | Jul 17 – Aug 21 | 85–110 |
| Cabbage | Feb 27 | Mar 20 | Apr 3 | Jun 5 – Jul 31 | 60–100 |
| Calabash | Feb 13 | Apr 10 | Apr 17 | Jul 10 – Sep 4 | 80–120 |
| Cardoon | — | — | Apr 17 | Aug 21 – Oct 2 | 120–150 |
| Carrots | — | Mar 20 | — | May 22 – Jun 26 | 60–80 |
| Cauliflower | Feb 27 | Mar 20 | Apr 3 | May 29 – Jul 31 | 55–100 |
| Celeriac | Feb 27 | Mar 20 | Apr 3 | Jul 17 – Aug 21 | 100–120 |
| Celery | Feb 27 | Mar 20 | Apr 3 | Jun 26 – Aug 21 | 80–120 |
| Celtuce | Feb 27 | Mar 20 | Apr 3 | Jun 5 – Jul 17 | 60–90 |
| Chard | Feb 27 | Mar 20 | Apr 3 | May 29 – Jul 17 | 50–60 |
| Chayote | Feb 13 | Apr 10 | Apr 17 | Aug 21 – Oct 30 | 120–180 |
| Chickpeas | Feb 27 | Mar 20 | Apr 3 | Jun 26 – Aug 7 | 80–110 |
| Chicory | Feb 27 | Mar 20 | Apr 3 | Jun 5 – Jul 17 | 60–85 |
| Chinese Cabbage | Feb 27 | Mar 20 | Apr 3 | May 29 – Jun 26 | 50–70 |
| Christmas Lima Beans | Feb 13 | Apr 10 | Apr 17 | Jul 10 – Aug 14 | 80–100 |
| Collard Greens | Feb 27 | Mar 20 | Apr 3 | May 29 – Jul 31 | 55–75 |
| Corn | — | Apr 10 | — | Jun 12 – Aug 7 | 60–100 |
| Cowpeas | — | Apr 10 | — | Jun 12 – Jul 24 | 60–90 |
| Cress | Feb 27 | Mar 20 | Apr 3 | Apr 17 – May 8 | 14–21 |
| Crookneck Squash | Mar 6 | Apr 10 | Apr 17 | Jun 5 – Jul 3 | 45–60 |
| Crosne | — | Mar 20 | — | Aug 21 – Oct 23 | 150–200 |
| Cucumber | Mar 6 | Apr 10 | Apr 17 | Jun 12 – Aug 7 | 50–70 |
| Daikon | — | Mar 20 | — | May 15 – Jun 12 | 50–70 |
| Delicata Squash | Mar 6 | Apr 10 | Apr 17 | Jul 10 – Aug 14 | 80–100 |
| Edamame | — | Apr 10 | — | Jun 26 – Aug 7 | 75–100 |
| Eggplant | Jan 30 | Apr 10 | Apr 17 | Jun 26 – Aug 28 | 65–85 |
| Endive | Feb 27 | Mar 20 | Apr 3 | May 22 – Jun 26 | 45–65 |
| Escarole | Feb 27 | Mar 20 | Apr 3 | May 29 – Jun 26 | 50–70 |
| Fava Beans | Feb 27 | Mar 20 | Apr 3 | Jun 19 – Jul 31 | 75–100 |
| Fennel | Feb 13 | Apr 10 | Apr 17 | Jun 19 – Jul 31 | 60–90 |
| Garlic | — | — | — | — | 90–240 |
| Green Beans | — | Apr 10 | — | Jun 5 – Jul 31 | 50–65 |
| Horseradish | — | — | Apr 17 | Aug 21 – Oct 30 | 120–180 |
| Hot Peppers | Jan 30 | Apr 10 | Apr 17 | Jun 26 – Oct 2 | 70–120 |
| Hubbard Squash | Mar 6 | Apr 10 | Apr 17 | Jul 31 – Sep 4 | 100–120 |
| Jicama | Feb 13 | Apr 10 | Apr 17 | Aug 21 – Oct 30 | 120–180 |
| Kabocha | Mar 6 | Apr 10 | Apr 17 | Jul 17 – Aug 14 | 85–100 |
| Kai Lan | Feb 27 | Mar 20 | Apr 3 | May 22 – Jun 19 | 45–60 |
| Kale | Feb 27 | Mar 20 | Apr 3 | May 29 – Jul 24 | 50–70 |
| Kidney Beans | — | Apr 10 | — | Jul 10 – Aug 14 | 85–110 |
| Kohlrabi | Feb 27 | Mar 20 | Apr 3 | May 22 – Jun 26 | 45–65 |
| Komatsuna | Feb 27 | Mar 20 | Apr 3 | May 8 – Jun 12 | 35–50 |
| Leeks | Feb 27 | Mar 20 | Apr 3 | Jul 3 – Sep 18 | 90–150 |
| Lentils | Feb 27 | Mar 20 | Apr 3 | Jun 26 – Aug 7 | 80–110 |
| Lettuce | Feb 27 | Mar 20 | Apr 3 | May 8 – Jul 17 | 30–60 |
| Lima Beans | — | Apr 10 | — | Jun 12 – Jul 24 | 60–90 |
| Loofah | Feb 13 | Apr 10 | Apr 17 | Jul 31 – Oct 2 | 100–150 |
| Luffa | Feb 13 | Apr 10 | Apr 17 | Jul 17 – Oct 2 | 90–150 |
| Mache | Feb 27 | Mar 20 | Apr 3 | May 15 – Jun 19 | 40–60 |
| Malabar Spinach | Feb 13 | Apr 10 | Apr 17 | Jun 12 – Jul 10 | 55–70 |
| Melon | Mar 6 | Apr 10 | Apr 17 | Jun 26 – Aug 14 | 70–100 |
| Microgreens | Feb 27 | Mar 20 | Apr 3 | Apr 10 – May 8 | 7–21 |
| Mitsuba | Feb 27 | Mar 20 | Mar 27 | May 22 – Jul 17 | 50–70 |
| Mizuna | Feb 27 | Mar 20 | Apr 3 | May 8 – Jun 5 | 30–45 |
| Mustard Greens | Feb 27 | Mar 20 | Apr 3 | May 8 – Jul 10 | 30–50 |
| Napa Cabbage | Feb 27 | Mar 20 | Apr 3 | May 29 – Jul 3 | 55–75 |
| New Zealand Spinach | Feb 13 | Apr 10 | Apr 17 | Jun 12 – Jul 10 | 55–70 |
| Okra | Feb 13 | Apr 10 | Apr 17 | Jun 12 – Aug 7 | 50–65 |
| Onion | Feb 27 | Mar 20 | Apr 3 | Jul 3 – Aug 21 | 90–120 |
| Pac Choi | Feb 27 | Mar 20 | Apr 3 | May 15 – Jun 12 | 40–55 |
| Parsnip | — | Mar 20 | — | Jul 3 – Aug 14 | 100–130 |
| Patty Pan Squash | Mar 6 | Apr 10 | Apr 17 | Jun 5 – Jul 3 | 45–60 |
| Peas | Feb 27 | Mar 20 | Apr 3 | May 29 – Jul 24 | 55–70 |
| Peppers | Jan 30 | Apr 10 | Apr 17 | Jun 19 – Aug 28 | 60–90 |
| Pole Beans | Feb 13 | Apr 10 | Apr 17 | Jun 12 – Aug 7 | 55–70 |
| Potatoes | Feb 13 | Apr 10 | Apr 17 | Jun 26 – Sep 4 | 70–120 |
| Pumpkin | Mar 6 | Apr 10 | Apr 17 | Jul 17 – Sep 4 | 85–120 |
| Purslane | Feb 27 | Mar 20 | Apr 3 | May 15 – Jun 19 | 40–60 |
| Radicchio | Feb 27 | Mar 20 | Apr 3 | Jun 5 – Jul 10 | 60–80 |
| Radish | — | Mar 20 | — | Apr 17 – May 8 | 22–35 |
| Rhubarb | — | — | Apr 24 | — | 365–730 |
| Romanesco | Feb 27 | Mar 20 | Apr 3 | Jun 19 – Jul 31 | 75–100 |
| Rutabaga | — | Mar 20 | — | Jun 12 – Jul 17 | 80–100 |
| Salsify | — | Mar 20 | — | Jul 3 – Aug 14 | 100–130 |
| Savoy Cabbage | Feb 27 | Mar 20 | Apr 3 | Jun 12 – Aug 7 | 70–110 |
| Scallions | Feb 27 | Mar 20 | Apr 3 | May 29 – Jun 26 | 50–70 |
| Scarlet Runner Beans | Feb 13 | Apr 10 | Apr 17 | Jun 19 – Jul 24 | 60–80 |
| Shallot | Feb 27 | Mar 20 | Apr 3 | Jul 3 – Aug 21 | 90–120 |
| Shiso | Feb 13 | Apr 10 | Apr 17 | Jun 12 – Aug 7 | 50–70 |
| Snap Peas | Feb 13 | Apr 10 | Apr 17 | Jun 12 – Aug 7 | 55–70 |
| Snow Peas | Feb 27 | Mar 20 | Apr 3 | May 29 – Jul 24 | 50–65 |
| Soybeans | — | Apr 10 | — | Jul 3 – Aug 28 | 80–120 |
| Spaghetti Squash | Mar 6 | Apr 10 | Apr 17 | Jul 17 – Aug 14 | 85–100 |
| Spinach | Feb 27 | Mar 20 | Apr 3 | May 8 – Jul 10 | 35–50 |
| Squash (Summer) | Mar 6 | Apr 10 | Apr 17 | Jun 5 – Aug 7 | 45–65 |
| Squash (Winter) | Mar 6 | Apr 10 | Apr 17 | Jul 10 – Sep 4 | 80–120 |
| Sunchoke | — | — | Apr 17 | Aug 7 – Oct 2 | 110–150 |
| Sunflower | Feb 13 | Apr 10 | Apr 17 | Jun 26 – Aug 14 | 70–100 |
| Sweet Corn | — | Apr 10 | — | Jun 12 – Jul 24 | 60–90 |
| Sweet Potatoes | Feb 13 | Apr 10 | Apr 17 | Jul 17 – Sep 4 | 90–120 |
| Tatsoi | Feb 27 | Mar 20 | Apr 3 | May 8 – Jun 12 | 35–50 |
| Tomatillo | Feb 13 | Apr 10 | Apr 17 | Jun 19 – Aug 28 | 60–85 |
| Tomatoes | Feb 13 | Apr 10 | Apr 17 | Jun 19 – Aug 28 | 60–85 |
| Turnip | — | Mar 20 | — | May 1 – Jun 5 | 40–60 |
| Watercress | Feb 27 | Mar 20 | Apr 3 | May 15 – Jun 19 | 40–60 |
| Watermelon | Mar 6 | Apr 10 | Apr 17 | Jun 26 – Aug 14 | 70–100 |
| Wax Beans | — | Apr 10 | — | Jun 5 – Jul 31 | 50–65 |
| Winter Melon | Feb 13 | Apr 10 | Apr 17 | Jul 17 – Sep 4 | 90–120 |
| Yard Long Beans | Feb 13 | Apr 10 | Apr 17 | Jun 12 – Jul 24 | 55–80 |
| Zucchini | Mar 6 | Apr 10 | Apr 17 | Jun 5 – Jul 31 | 45–60 |
🍓 Fruits to Grow in Benton County
31 fruits that grow well in Zone 7a with planting dates for Benton County.
Show all 31 fruits with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Alpine Strawberries | — | — | Apr 24 | Jul 24 – Nov 6 | 90–180 |
| Aronia | — | — | Apr 24 | — | 730–1095 |
| Blackberries | — | — | Apr 24 | — | 365–730 |
| Blueberries | — | — | Apr 24 | — | 730–1095 |
| Boysenberries | — | — | Apr 24 | — | 365–730 |
| Cantaloupe | — | — | Apr 24 | Jul 3 – Aug 7 | 70–90 |
| Che Fruit | — | — | Apr 24 | — | 1095–1825 |
| Cranberries | — | — | Apr 24 | — | 730–1095 |
| Currants | — | — | Apr 24 | — | 730–1095 |
| Elderberries | — | — | Apr 24 | — | 730–1095 |
| Figs | — | — | Apr 24 | — | 730–1825 |
| Goji Berries | — | — | Apr 24 | — | 730–1095 |
| Gooseberries | — | — | Apr 24 | — | 730–1095 |
| Grapes | — | — | Apr 24 | — | 730–1095 |
| Ground Cherry | — | — | Apr 24 | Jul 3 – Aug 28 | 65–80 |
| Hardy Kiwi | — | — | Apr 24 | — | 1095–1825 |
| Haskaps | — | — | Apr 24 | — | 730–1095 |
| Honeydew | — | — | Apr 24 | Jul 17 – Aug 28 | 80–110 |
| Jostaberry | — | — | Apr 24 | — | 730–1095 |
| Kiwi | — | — | Apr 24 | — | 1095–1825 |
| Lingonberries | — | — | Apr 24 | — | 730–1095 |
| Loquat | — | — | Apr 24 | — | 730–1825 |
| Medlar | — | — | Apr 24 | — | 1095–1825 |
| Mulberries | — | — | Apr 24 | — | 730–1825 |
| Pawpaw | — | — | Apr 24 | — | 1095–2555 |
| Persimmon | — | — | Apr 24 | — | 1095–2555 |
| Pomegranate | — | — | Apr 24 | — | 730–1095 |
| Quince | — | — | Apr 24 | — | 1095–1825 |
| Raspberries | — | — | Apr 24 | — | 365–730 |
| Serviceberries | — | — | Apr 24 | — | 730–1095 |
| Strawberries | — | — | Apr 24 | Jul 24 – Dec 4 | 90–365 |
🌿 Herbs to Grow in Benton County
39 herbs that grow well in Zone 7a with planting dates for Benton County.
Show all 39 herbs with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Angelica | Feb 27 | Mar 20 | Mar 27 | — | 365–730 |
| Anise | Feb 27 | Mar 20 | Mar 27 | Jun 26 – Sep 11 | 90–120 |
| Basil | Feb 13 | Apr 10 | Apr 17 | Jun 12 – Aug 14 | 50–75 |
| Bee Balm | — | — | Apr 10 | Jul 10 – Sep 25 | 90–120 |
| Borage | Feb 27 | Mar 20 | Mar 27 | May 22 – Jul 10 | 50–60 |
| Caraway | Feb 27 | Mar 20 | Mar 27 | — | 365–450 |
| Catnip | — | — | Apr 10 | Jun 12 – Aug 14 | 60–80 |
| Chamomile | Feb 27 | Mar 20 | Mar 27 | May 29 – Aug 7 | 60–90 |
| Chervil | Feb 27 | Mar 20 | Mar 27 | May 8 – Jul 10 | 40–60 |
| Chives | — | — | Apr 10 | Jun 12 – Aug 21 | 60–90 |
| Cilantro | Feb 27 | Mar 20 | Mar 27 | May 8 – Jul 10 | 40–60 |
| Comfrey | — | — | Apr 10 | Jun 12 – Aug 21 | 60–90 |
| Cumin | Feb 27 | Mar 20 | Mar 27 | Jul 10 – Sep 11 | 100–120 |
| Dill | Feb 27 | Mar 20 | Mar 27 | May 8 – Jul 10 | 40–60 |
| Echinacea | — | — | Apr 10 | Aug 14 – Nov 20 | 120–180 |
| Epazote | Feb 13 | Apr 10 | Apr 17 | Jun 5 – Jul 31 | 45–60 |
| Fennel (herb) | Feb 27 | Mar 20 | Mar 27 | May 29 – Aug 7 | 60–90 |
| Feverfew | — | — | Apr 10 | Jul 10 – Sep 25 | 90–120 |
| Garlic Chives | — | — | Apr 10 | Jun 12 – Aug 21 | 60–90 |
| Horehound | — | — | Apr 10 | Jun 26 – Aug 21 | 75–90 |
| Hyssop | — | — | Apr 10 | Jun 19 – Aug 21 | 70–90 |
| Lavender | — | — | Apr 10 | Jul 10 – Nov 20 | 90–200 |
| Lemon Balm | — | — | Apr 10 | Jun 12 – Jul 31 | 60–70 |
| Lemon Thyme | — | — | Apr 10 | Jun 19 – Aug 21 | 70–90 |
| Lovage | — | — | Apr 10 | Jun 19 – Aug 21 | 70–90 |
| Marjoram | — | — | Apr 10 | Jun 12 – Aug 21 | 60–90 |
| Mint | — | — | Apr 10 | Jun 12 – Aug 21 | 60–90 |
| Oregano | — | — | Apr 10 | Jun 12 – Aug 21 | 60–90 |
| Parsley | Feb 27 | Mar 20 | Mar 27 | May 29 – Jul 31 | 60–80 |
| Rosemary | — | — | Apr 10 | Jul 3 – Nov 20 | 80–180 |
| Rue | — | — | Apr 10 | Jun 19 – Aug 21 | 70–90 |
| Sage | — | — | Apr 10 | Jun 26 – Aug 21 | 75–90 |
| Savory | — | — | Apr 10 | Jun 5 – Jul 31 | 50–70 |
| Sorrel | Feb 27 | Mar 20 | Mar 27 | May 8 – Jul 10 | 40–60 |
| Tarragon | — | — | Apr 10 | Jun 12 – Aug 21 | 60–90 |
| Thai Basil | Feb 13 | Apr 10 | Apr 17 | Jun 12 – Aug 14 | 50–75 |
| Thyme | — | — | Apr 10 | Jun 19 – Aug 21 | 70–90 |
| Valerian | — | — | Apr 10 | Aug 14 – Nov 20 | 120–180 |
| Yarrow | — | — | Apr 10 | Jul 10 – Sep 25 | 90–120 |
Monthly Planting Guide for Benton County
Gardening Guides & Resources
Helpful guides from The Ultimate Homestead to improve your garden in Benton County.
Frequently Asked Questions
What planting zone is Benton County, WA?
Benton County is in USDA Hardiness Zone 7a. 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 Benton County, WA?
Based on 31 years of NOAA weather station data, the median last spring frost in Benton County falls around April 3. In 8 out of 10 years, last frost lands between March 14 and April 20 — a 36-day window of variability. Use April 20 as your conservative safe-to-plant date for frost-sensitive crops.
When is the first fall frost in Benton County, WA?
The median first fall frost in Benton County arrives around October 27. In cold years it can arrive as early as October 9; in mild years as late as November 10. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.
How long is the growing season in Benton County?
Benton County has a frost-free growing season of approximately 207 days. This long season supports multiple succession plantings and warm-season crops that need extended heat, like sweet potatoes and melons. Climate records show the growing season is trending longer by about 2.56 days per decade.
What is the soil like in Benton County for gardening?
Benton County has predominantly Silt Loam soil with a pH range of 5.5–6.3 and Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.
What is grown commercially in Benton County?
Benton County has commercial agriculture that includes Wheat, Hay, Potatoes, Apples, Cattle. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.
Is Benton County a good location for home gardening?
Benton County scores 50/100 (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 Benton County gardeners in Zone 7a 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.
