Cowlitz County, WA — Planting Guide
Cowlitz County is in USDA Zone 8a. The average last spring frost is April 15 and the first fall frost is October 29, giving you a growing season of approximately 197 days.
At an elevation of 268 ft, Cowlitz County receives approximately 47.4 in of rainfall annually. Summer highs average 87°F with winter lows around 42°F. The predominant soil type is Silt 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 24 in warm years to May 7 in cold years. The growing season is trending shorter by about 4.1 days per decade. Cowlitz County scores 63/100 (Good) on the Microclimate Index.
🌡️ Zone
8a (10°F to 15°F min)
❄️ Last Frost
April 15
🍂 First Frost
October 29
📅 Growing Season
197 days
⛰️ Elevation
268 ft
🌧️ Annual Rainfall
47.4 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 | 7.2 in | 18 days | — | None |
| Feb | 4.6 in | 12 days | — | Low |
| Mar | 5.1 in | 15 days | — | Low |
| Apr | 3.6 in | 13 days | 0.7 in | Moderate |
| May | 2.9 in | 10 days | 1.4 in | Moderate |
| Jun | 2 in | 6 days | 2.3 in | High |
| Jul | 0.8 in | 3 days | 3.5 in | Critical |
| Aug | 0.9 in | 2 days | 3.4 in | Critical |
| Sep | 1.6 in | 5 days | 2.7 in | High |
| Oct | 3.4 in | 11 days | 0.9 in | Moderate |
| Nov | 7.6 in | 14 days | — | Low |
| Dec | 7.7 in | 18 days | — | None |
Annual total: 47.4 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.
Cowlitz County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.5
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 7 | Nov 24 | 201 days |
| Cautious | Apr 24 | Nov 7 | 197 days |
| Average year | Apr 15 | Oct 29 | 197 days |
| Optimistic | Apr 9 | Oct 20 | 194 days |
| Aggressive (risky) | Mar 24 | Oct 9 | 199 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 shorter here (about 4.1 days per decade). Use the "Conservative" dates and choose fast-maturing varieties.
Gardening Difficulty Score
Cowlitz County offers good growing conditions. A little planning around frost dates goes a long way.
Local Gardening Help in Cowlitz 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 Cowlitz County's climate and soil.
County Extension Office
Cowlitz 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 Cowlitz County
Finding local nurseries & garden centers in Cowlitz County
Why Buy Local
Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Cowlitz 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 Cowlitz County WA" or "garden center Cowlitz 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 Cowlitz County WA" or check your extension office and local parks department. Facebook groups like "Cowlitz 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
11 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 | 2.3 hr | Short day |
| February | 10.1 hr | 3.1 hr | Short day |
| March | 11.6 hr | 4 hr | Short day |
| April | 13.3 hr | 5.3 hr | Neutral |
| May | 14.8 hr | 7.8 hr | Long day |
| June | 15.6 hr | 8.4 hr | Long day |
| July | 15.2 hr | 11 hr | Long day |
| August | 14 hr | 9.6 hr | Long day |
| September | 12.3 hr | 7.5 hr | Neutral |
| October | 10.6 hr | 4.1 hr | Short day |
| November | 9.2 hr | 2.4 hr | Short day |
| December | 8.4 hr | 1.8 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 Apr through Nov.
Best Month to Compost
May
Microbial activity peaks when soil is warm.
Active Composting
10 months
Nearly year-round composting.
View detailed monthly data
| Month | Soil 4" Deep | Soil 8" Deep | Compost Activity | Time to Finish |
|---|---|---|---|---|
| Jan | 45°F | 50°F | 🐢 Slow | ~24 weeks |
| Feb | 44°F | 48°F | 🐢 Slow | ~24 weeks |
| Mar | 53°F | 53°F | ♻️ Active | ~14 weeks |
| Apr | 62°F | 61°F | ♻️ Active | ~14 weeks |
| May | 73°F | 69°F | 🔥 Peak | ~8 weeks |
| Jun | 83°F | 76°F | 🔥 Peak | ~8 weeks |
| Jul | 90°F | 84°F | 🔥 Peak | ~8 weeks |
| Aug | 91°F | 85°F | 🔥 Peak | ~8 weeks |
| Sep | 83°F | 83°F | 🔥 Peak | ~8 weeks |
| Oct | 71°F | 75°F | 🔥 Peak | ~8 weeks |
| Nov | 61°F | 63°F | ♻️ Active | ~14 weeks |
| Dec | 50°F | 56°F | ♻️ Active | ~14 weeks |
Highlighted rows = soil 60°F+ (safe for warm-season transplants). Compost finishes fastest during peak activity months.
Pest & Disease Pressure in Cowlitz County
Computed from local climate patterns — warmer, humid conditions increase pest generations and fungal disease risk.
Insect Pest Pressure
High — expect multiple pest generations. Preventative measures essential.
Disease Risk
High fungal/bacterial risk. Space plants for airflow, water at soil level.
Seasonal Risk
View 6 common pests in your area
| Pest | Risk Level | Peak Months |
|---|---|---|
| Aphids | High | Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov |
| Squash vine borers | Moderate | May, Jun, Jul |
| Stink bugs | High | Apr, May, Jun, Jul, Aug, Sep, Oct |
| Whiteflies | Moderate | May, Jun, Jul, Aug, Sep, Oct |
| Spider mites | High | Jun, Jul, Aug, Sep |
| Fire ants | Moderate | Mar, Apr, May, Jun, Jul, Aug, Sep, Oct |
Organic pest management tips
- Install physical barriers: floating row covers, copper tape for slugs, mesh netting
- Apply Bt (Bacillus thuringiensis) for caterpillar control — safe for beneficial insects
- Use kaolin clay spray to deter a wide range of insects on fruiting crops
- Release beneficial insects: ladybugs for aphids, parasitic wasps for caterpillars
- Apply neem oil weekly during high-pressure months
- Mulch heavily (3-4 inches) to reduce soil-borne disease splash
Cover Crops for Cowlitz County
Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with county-specific planting dates.
Spring Cover Crops (4 options) — Build soil before the main growing season
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Buckwheat | Apr 19 | Aug 20 | — | Rapid growth, attracts pollinators, suppresses weeds |
| Cowpeas (southern peas) | Apr 17 | Aug 27 | ✓ Yes | Excellent nitrogen fixer for warm climates, edible |
| Sorghum-sudan grass | Apr 23 | Aug 20 | — | Massive biomass, breaks compaction, suppresses nematodes |
| White clover | Mar 17 | Aug 20 | ✓ 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 11 | Oct 1 | — | 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 | Aug 21 | Mar 25 | ✓ Yes | Fixes nitrogen, good for heavy clay soils |
| Crimson clover | Aug 23 | Mar 25 | ✓ Yes | Fixes nitrogen, attracts pollinators in spring |
| Daikon radish | Sep 9 | Apr 1 | — | Deep taproot breaks compaction, excellent for clay soils |
| Hairy vetch | Aug 12 | Mar 25 | ✓ Yes | Excellent nitrogen fixer, good for depleted soils |
| Oats | Sep 22 | Apr 1 | — | Quick biomass, winterkills in cold zones — no spring tillage needed |
| Winter rye | Aug 5 | Apr 1 | — | Suppresses weeds, prevents erosion, breaks up compacted soil |
| Winter wheat | Aug 9 | Mar 25 | — | 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: 13 mph Summer: 9 mph
Fall: 8 mph Winter: 12 mph
Prevailing wind: SW. Moderate wind — consider a temporary windbreak for young seedlings.
Windbreak Benefit
5.5/10
Moderately beneficial — a simple fence or trellis can protect delicate crops from wind stress.
Frost Pocket Risk
Moderate
Some terrain variation (510 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
23,624 gal
Per 1,000 sq ft of roof area (at 80% collection efficiency)
Recommended Setup
6 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
Jan, Mar, Nov, Dec
Highest rainfall months — your barrels will fill up quickly during these months.
Months to Draw From Storage
Jul, Aug
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 47.4 inches of rain per year
- A 1,000 sq ft roof can collect roughly 23,624 gallons annually
- Rainwater harvesting is fully legal in your state
- Use a first-flush diverter to keep roof debris out of your collection
Soil & Growing Conditions in Cowlitz County
Soil Type
Silt Loam
Soil pH 5.7–6.5 · Moderately Well Drained drainage
Native soil is well-suited to most vegetables and herbs with regular compost additions.
Watering Needs
Drought stress: 1.5/10
Cowlitz County has very low drought pressure. Natural rainfall usually meets garden needs — water only during extended dry spells.
Season Tips
197-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 Cowlitz County
115 vegetables that grow well in Zone 8a with planting dates for Cowlitz County.
Show all 115 vegetables with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Acorn Squash | Mar 18 | Apr 22 | Apr 29 | Jul 22 – Aug 26 | 80–100 |
| Amaranth | Feb 25 | Apr 22 | Apr 29 | Jul 29 – Sep 16 | 90–120 |
| Artichoke | — | — | Apr 29 | Sep 2 – Nov 11 | 120–180 |
| Arugula | Mar 11 | Apr 1 | Apr 15 | May 20 – Jul 22 | 30–50 |
| Asparagus | — | — | Apr 29 | — | 730–1095 |
| Beets | — | Apr 1 | — | May 27 – Jun 24 | 50–70 |
| Belgian Endive | Mar 11 | Apr 1 | Apr 15 | Aug 5 – Sep 30 | 110–150 |
| Bitter Melon | Feb 25 | Apr 22 | Apr 29 | Jul 1 – Aug 12 | 60–90 |
| Black Beans | — | Apr 22 | — | Jul 22 – Sep 9 | 90–120 |
| Bok Choy | Mar 11 | Apr 1 | Apr 15 | May 27 – Jul 1 | 40–60 |
| Broccoli | Mar 11 | Apr 1 | Apr 15 | Jun 17 – Jul 29 | 60–90 |
| Broccoli Rabe | Mar 11 | Apr 1 | Apr 15 | May 27 – Jul 1 | 40–60 |
| Brussels Sprouts | Mar 11 | Apr 1 | Apr 15 | Jul 15 – Sep 9 | 90–130 |
| Butternut Squash | Mar 18 | Apr 22 | Apr 29 | Jul 29 – Sep 2 | 85–110 |
| Cabbage | Mar 11 | Apr 1 | Apr 15 | Jun 17 – Aug 12 | 60–100 |
| Calabash | Feb 25 | Apr 22 | Apr 29 | Jul 22 – Sep 16 | 80–120 |
| Cardoon | — | — | Apr 29 | Sep 2 – Oct 14 | 120–150 |
| Carrots | — | Apr 1 | — | Jun 3 – Jul 8 | 60–80 |
| Cauliflower | Mar 11 | Apr 1 | Apr 15 | Jun 10 – Aug 12 | 55–100 |
| Celeriac | Mar 11 | Apr 1 | Apr 15 | Jul 29 – Sep 2 | 100–120 |
| Celery | Mar 11 | Apr 1 | Apr 15 | Jul 8 – Sep 2 | 80–120 |
| Celtuce | Mar 11 | Apr 1 | Apr 15 | Jun 17 – Jul 29 | 60–90 |
| Chard | Mar 11 | Apr 1 | Apr 15 | Jun 10 – Jul 29 | 50–60 |
| Chayote | Feb 25 | Apr 22 | Apr 29 | Sep 2 – Nov 11 | 120–180 |
| Chickpeas | Mar 11 | Apr 1 | Apr 15 | Jul 8 – Aug 19 | 80–110 |
| Chicory | Mar 11 | Apr 1 | Apr 15 | Jun 17 – Jul 29 | 60–85 |
| Chinese Cabbage | Mar 11 | Apr 1 | Apr 15 | Jun 10 – Jul 8 | 50–70 |
| Christmas Lima Beans | Feb 25 | Apr 22 | Apr 29 | Jul 22 – Aug 26 | 80–100 |
| Collard Greens | Mar 11 | Apr 1 | Apr 15 | Jun 10 – Aug 12 | 55–75 |
| Corn | — | Apr 22 | — | Jun 24 – Aug 19 | 60–100 |
| Cowpeas | — | Apr 22 | — | Jun 24 – Aug 5 | 60–90 |
| Cress | Mar 11 | Apr 1 | Apr 15 | Apr 29 – May 20 | 14–21 |
| Crookneck Squash | Mar 18 | Apr 22 | Apr 29 | Jun 17 – Jul 15 | 45–60 |
| Crosne | — | Apr 1 | — | Sep 2 – Nov 4 | 150–200 |
| Cucumber | Mar 18 | Apr 22 | Apr 29 | Jun 24 – Aug 19 | 50–70 |
| Daikon | — | Apr 1 | — | May 27 – Jun 24 | 50–70 |
| Delicata Squash | Mar 18 | Apr 22 | Apr 29 | Jul 22 – Aug 26 | 80–100 |
| Edamame | — | Apr 22 | — | Jul 8 – Aug 19 | 75–100 |
| Eggplant | Feb 11 | Apr 22 | Apr 29 | Jul 8 – Sep 9 | 65–85 |
| Endive | Mar 11 | Apr 1 | Apr 15 | Jun 3 – Jul 8 | 45–65 |
| Escarole | Mar 11 | Apr 1 | Apr 15 | Jun 10 – Jul 8 | 50–70 |
| Fava Beans | Mar 11 | Apr 1 | Apr 15 | Jul 1 – Aug 12 | 75–100 |
| Fennel | Feb 25 | Apr 22 | Apr 29 | Jul 1 – Aug 12 | 60–90 |
| Garlic | — | — | — | — | 90–240 |
| Ginger | Feb 25 | Apr 22 | Apr 29 | Dec 30 – Jan 13 | 240–300 |
| Green Beans | — | Apr 22 | — | Jun 17 – Aug 12 | 50–65 |
| Horseradish | — | — | Apr 29 | Sep 2 – Nov 11 | 120–180 |
| Hot Peppers | Feb 11 | Apr 22 | Apr 29 | Jul 8 – Oct 14 | 70–120 |
| Hubbard Squash | Mar 18 | Apr 22 | Apr 29 | Aug 12 – Sep 16 | 100–120 |
| Jicama | Feb 25 | Apr 22 | Apr 29 | Sep 2 – Nov 11 | 120–180 |
| Kabocha | Mar 18 | Apr 22 | Apr 29 | Jul 29 – Aug 26 | 85–100 |
| Kai Lan | Mar 11 | Apr 1 | Apr 15 | Jun 3 – Jul 1 | 45–60 |
| Kale | Mar 11 | Apr 1 | Apr 15 | Jun 10 – Aug 5 | 50–70 |
| Kidney Beans | — | Apr 22 | — | Jul 22 – Aug 26 | 85–110 |
| Kohlrabi | Mar 11 | Apr 1 | Apr 15 | Jun 3 – Jul 8 | 45–65 |
| Komatsuna | Mar 11 | Apr 1 | Apr 15 | May 20 – Jun 24 | 35–50 |
| Leeks | Mar 11 | Apr 1 | Apr 15 | Jul 15 – Sep 30 | 90–150 |
| Lentils | Mar 11 | Apr 1 | Apr 15 | Jul 8 – Aug 19 | 80–110 |
| Lettuce | Mar 11 | Apr 1 | Apr 15 | May 20 – Jul 29 | 30–60 |
| Lima Beans | — | Apr 22 | — | Jun 24 – Aug 5 | 60–90 |
| Loofah | Feb 25 | Apr 22 | Apr 29 | Aug 12 – Oct 14 | 100–150 |
| Luffa | Feb 25 | Apr 22 | Apr 29 | Jul 29 – Oct 14 | 90–150 |
| Mache | Mar 11 | Apr 1 | Apr 15 | May 27 – Jul 1 | 40–60 |
| Malabar Spinach | Feb 25 | Apr 22 | Apr 29 | Jun 24 – Jul 22 | 55–70 |
| Melon | Mar 18 | Apr 22 | Apr 29 | Jul 8 – Aug 26 | 70–100 |
| Microgreens | Mar 11 | Apr 1 | Apr 15 | Apr 22 – May 20 | 7–21 |
| Mitsuba | Mar 11 | Apr 1 | Apr 8 | Jun 3 – Jul 29 | 50–70 |
| Mizuna | Mar 11 | Apr 1 | Apr 15 | May 20 – Jun 17 | 30–45 |
| Mustard Greens | Mar 11 | Apr 1 | Apr 15 | May 20 – Jul 22 | 30–50 |
| Napa Cabbage | Mar 11 | Apr 1 | Apr 15 | Jun 10 – Jul 15 | 55–75 |
| New Zealand Spinach | Feb 25 | Apr 22 | Apr 29 | Jun 24 – Jul 22 | 55–70 |
| Okra | Feb 25 | Apr 22 | Apr 29 | Jun 24 – Aug 19 | 50–65 |
| Onion | Mar 11 | Apr 1 | Apr 15 | Jul 15 – Sep 2 | 90–120 |
| Pac Choi | Mar 11 | Apr 1 | Apr 15 | May 27 – Jun 24 | 40–55 |
| Parsnip | — | Apr 1 | — | Jul 15 – Aug 26 | 100–130 |
| Patty Pan Squash | Mar 18 | Apr 22 | Apr 29 | Jun 17 – Jul 15 | 45–60 |
| Peas | Mar 11 | Apr 1 | Apr 15 | Jun 10 – Aug 5 | 55–70 |
| Peppers | Feb 11 | Apr 22 | Apr 29 | Jul 1 – Sep 9 | 60–90 |
| Pole Beans | Feb 25 | Apr 22 | Apr 29 | Jun 24 – Aug 19 | 55–70 |
| Potatoes | Feb 25 | Apr 22 | Apr 29 | Jul 8 – Sep 16 | 70–120 |
| Pumpkin | Mar 18 | Apr 22 | Apr 29 | Jul 29 – Sep 16 | 85–120 |
| Purslane | Mar 11 | Apr 1 | Apr 15 | May 27 – Jul 1 | 40–60 |
| Radicchio | Mar 11 | Apr 1 | Apr 15 | Jun 17 – Jul 22 | 60–80 |
| Radish | — | Apr 1 | — | Apr 29 – May 20 | 22–35 |
| Rhubarb | — | — | May 6 | — | 365–730 |
| Romanesco | Mar 11 | Apr 1 | Apr 15 | Jul 1 – Aug 12 | 75–100 |
| Rutabaga | — | Apr 1 | — | Jun 24 – Jul 29 | 80–100 |
| Salsify | — | Apr 1 | — | Jul 15 – Aug 26 | 100–130 |
| Savoy Cabbage | Mar 11 | Apr 1 | Apr 15 | Jun 24 – Aug 19 | 70–110 |
| Scallions | Mar 11 | Apr 1 | Apr 15 | Jun 10 – Jul 8 | 50–70 |
| Scarlet Runner Beans | Feb 25 | Apr 22 | Apr 29 | Jul 1 – Aug 5 | 60–80 |
| Shallot | Mar 11 | Apr 1 | Apr 15 | Jul 15 – Sep 2 | 90–120 |
| Shiso | Feb 25 | Apr 22 | Apr 29 | Jun 24 – Aug 19 | 50–70 |
| Snap Peas | Feb 25 | Apr 22 | Apr 29 | Jun 24 – Aug 19 | 55–70 |
| Snow Peas | Mar 11 | Apr 1 | Apr 15 | Jun 10 – Aug 5 | 50–65 |
| Soybeans | — | Apr 22 | — | Jul 15 – Sep 9 | 80–120 |
| Spaghetti Squash | Mar 18 | Apr 22 | Apr 29 | Jul 29 – Aug 26 | 85–100 |
| Spinach | Mar 11 | Apr 1 | Apr 15 | May 20 – Jul 22 | 35–50 |
| Squash (Summer) | Mar 18 | Apr 22 | Apr 29 | Jun 17 – Aug 19 | 45–65 |
| Squash (Winter) | Mar 18 | Apr 22 | Apr 29 | Jul 22 – Sep 16 | 80–120 |
| Sunchoke | — | — | Apr 29 | Aug 19 – Oct 14 | 110–150 |
| Sunflower | Feb 25 | Apr 22 | Apr 29 | Jul 8 – Aug 26 | 70–100 |
| Sweet Corn | — | Apr 22 | — | Jun 24 – Aug 5 | 60–90 |
| Sweet Potatoes | Feb 25 | Apr 22 | Apr 29 | Jul 29 – Sep 16 | 90–120 |
| Tatsoi | Mar 11 | Apr 1 | Apr 15 | May 20 – Jun 24 | 35–50 |
| Tomatillo | Feb 25 | Apr 22 | Apr 29 | Jul 1 – Sep 9 | 60–85 |
| Tomatoes | Feb 25 | Apr 22 | Apr 29 | Jul 1 – Sep 9 | 60–85 |
| Turmeric | Feb 25 | Apr 22 | Apr 29 | Dec 30 – Jan 13 | 240–300 |
| Turnip | — | Apr 1 | — | May 13 – Jun 17 | 40–60 |
| Watercress | Mar 11 | Apr 1 | Apr 15 | May 27 – Jul 1 | 40–60 |
| Watermelon | Mar 18 | Apr 22 | Apr 29 | Jul 8 – Aug 26 | 70–100 |
| Wax Beans | — | Apr 22 | — | Jun 17 – Aug 12 | 50–65 |
| Winter Melon | Feb 25 | Apr 22 | Apr 29 | Jul 29 – Sep 16 | 90–120 |
| Yard Long Beans | Feb 25 | Apr 22 | Apr 29 | Jun 24 – Aug 5 | 55–80 |
| Zucchini | Mar 18 | Apr 22 | Apr 29 | Jun 17 – Aug 12 | 45–60 |
🍓 Fruits to Grow in Cowlitz County
27 fruits that grow well in Zone 8a with planting dates for Cowlitz County.
Show all 27 fruits with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Alpine Strawberries | — | — | May 6 | Aug 5 – Nov 18 | 90–180 |
| Aronia | — | — | May 6 | — | 730–1095 |
| Blackberries | — | — | May 6 | — | 365–730 |
| Blueberries | — | — | May 6 | — | 730–1095 |
| Boysenberries | — | — | May 6 | — | 365–730 |
| Cantaloupe | — | — | May 6 | Jul 15 – Aug 19 | 70–90 |
| Che Fruit | — | — | May 6 | — | 1095–1825 |
| Elderberries | — | — | May 6 | — | 730–1095 |
| Figs | — | — | May 6 | — | 730–1825 |
| Goji Berries | — | — | May 6 | — | 730–1095 |
| Gooseberries | — | — | May 6 | — | 730–1095 |
| Grapes | — | — | May 6 | — | 730–1095 |
| Ground Cherry | — | — | May 6 | Jul 15 – Sep 9 | 65–80 |
| Hardy Kiwi | — | — | May 6 | — | 1095–1825 |
| Honeydew | — | — | May 6 | Jul 29 – Sep 9 | 80–110 |
| Jostaberry | — | — | May 6 | — | 730–1095 |
| Kiwi | — | — | May 6 | — | 1095–1825 |
| Loquat | — | — | May 6 | — | 730–1825 |
| Medlar | — | — | May 6 | — | 1095–1825 |
| Mulberries | — | — | May 6 | — | 730–1825 |
| Pawpaw | — | — | May 6 | — | 1095–2555 |
| Persimmon | — | — | May 6 | — | 1095–2555 |
| Pomegranate | — | — | May 6 | — | 730–1095 |
| Quince | — | — | May 6 | — | 1095–1825 |
| Raspberries | — | — | May 6 | — | 365–730 |
| Serviceberries | — | — | May 6 | — | 730–1095 |
| Strawberries | — | — | May 6 | Aug 5 – Jan 20 | 90–365 |
🌿 Herbs to Grow in Cowlitz County
42 herbs that grow well in Zone 8a with planting dates for Cowlitz County.
Show all 42 herbs with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Angelica | Mar 11 | Apr 1 | Apr 8 | — | 365–730 |
| Anise | Mar 11 | Apr 1 | Apr 8 | Jul 8 – Sep 23 | 90–120 |
| Basil | Feb 25 | Apr 22 | Apr 29 | Jun 24 – Aug 26 | 50–75 |
| Bee Balm | — | — | Apr 22 | Jul 22 – Oct 7 | 90–120 |
| Borage | Mar 11 | Apr 1 | Apr 8 | Jun 3 – Jul 22 | 50–60 |
| Caraway | Mar 11 | Apr 1 | Apr 8 | — | 365–450 |
| Catnip | — | — | Apr 22 | Jun 24 – Aug 26 | 60–80 |
| Chamomile | Mar 11 | Apr 1 | Apr 8 | Jun 10 – Aug 19 | 60–90 |
| Chervil | Mar 11 | Apr 1 | Apr 8 | May 20 – Jul 22 | 40–60 |
| Chives | — | — | Apr 22 | Jun 24 – Sep 2 | 60–90 |
| Cilantro | Mar 11 | Apr 1 | Apr 8 | May 20 – Jul 22 | 40–60 |
| Comfrey | — | — | Apr 22 | Jun 24 – Sep 2 | 60–90 |
| Cumin | Mar 11 | Apr 1 | Apr 8 | Jul 22 – Sep 23 | 100–120 |
| Dill | Mar 11 | Apr 1 | Apr 8 | May 20 – Jul 22 | 40–60 |
| Echinacea | — | — | Apr 22 | Aug 26 – Dec 2 | 120–180 |
| Epazote | Feb 25 | Apr 22 | Apr 29 | Jun 17 – Aug 12 | 45–60 |
| Fennel (herb) | Mar 11 | Apr 1 | Apr 8 | Jun 10 – Aug 19 | 60–90 |
| Feverfew | — | — | Apr 22 | Jul 22 – Oct 7 | 90–120 |
| Garlic Chives | — | — | Apr 22 | Jun 24 – Sep 2 | 60–90 |
| Horehound | — | — | Apr 22 | Jul 8 – Sep 2 | 75–90 |
| Hyssop | — | — | Apr 22 | Jul 1 – Sep 2 | 70–90 |
| Lavender | — | — | Apr 22 | Jul 22 – Dec 23 | 90–200 |
| Lemon Balm | — | — | Apr 22 | Jun 24 – Aug 12 | 60–70 |
| Lemon Thyme | — | — | Apr 22 | Jul 1 – Sep 2 | 70–90 |
| Lemon Verbena | Feb 25 | Apr 22 | Apr 29 | Jul 1 – Sep 9 | 60–90 |
| Lemongrass | Feb 25 | Apr 22 | Apr 29 | Jul 15 – Oct 14 | 75–120 |
| Lovage | — | — | Apr 22 | Jul 1 – Sep 2 | 70–90 |
| Marjoram | — | — | Apr 22 | Jun 24 – Sep 2 | 60–90 |
| Mint | — | — | Apr 22 | Jun 24 – Sep 2 | 60–90 |
| Oregano | — | — | Apr 22 | Jun 24 – Sep 2 | 60–90 |
| Parsley | Mar 11 | Apr 1 | Apr 8 | Jun 10 – Aug 12 | 60–80 |
| Rosemary | — | — | Apr 22 | Jul 15 – Dec 2 | 80–180 |
| Rue | — | — | Apr 22 | Jul 1 – Sep 2 | 70–90 |
| Sage | — | — | Apr 22 | Jul 8 – Sep 2 | 75–90 |
| Savory | — | — | Apr 22 | Jun 17 – Aug 12 | 50–70 |
| Sorrel | Mar 11 | Apr 1 | Apr 8 | May 20 – Jul 22 | 40–60 |
| Stevia | Feb 25 | Apr 22 | Apr 29 | Jul 1 – Sep 9 | 60–90 |
| Tarragon | — | — | Apr 22 | Jun 24 – Sep 2 | 60–90 |
| Thai Basil | Feb 25 | Apr 22 | Apr 29 | Jun 24 – Aug 26 | 50–75 |
| Thyme | — | — | Apr 22 | Jul 1 – Sep 2 | 70–90 |
| Valerian | — | — | Apr 22 | Aug 26 – Dec 2 | 120–180 |
| Yarrow | — | — | Apr 22 | Jul 22 – Oct 7 | 90–120 |
Monthly Planting Guide for Cowlitz County
Gardening Guides & Resources
Helpful guides from The Ultimate Homestead to improve your garden in Cowlitz County.
Frequently Asked Questions
What planting zone is Cowlitz County, WA?
Cowlitz County is in USDA Hardiness Zone 8a. 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 Cowlitz County, WA?
Based on 31 years of NOAA weather station data, the median last spring frost in Cowlitz County falls around April 15. In 8 out of 10 years, last frost lands between March 24 and May 7 — a 43-day window of variability. Use May 7 as your conservative safe-to-plant date for frost-sensitive crops.
When is the first fall frost in Cowlitz County, WA?
The median first fall frost in Cowlitz County arrives around October 29. In cold years it can arrive as early as October 9; in mild years as late as November 24. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.
How long is the growing season in Cowlitz County?
Cowlitz County has a frost-free growing season of approximately 197 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 shorter by about 4.1 days per decade.
What is the soil like in Cowlitz County for gardening?
Cowlitz County has predominantly Silt Loam soil with a pH range of 5.7–6.5 and Moderately Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.
What is grown commercially in Cowlitz County?
Cowlitz County has commercial agriculture that includes Wheat, Hay, Apples, Potatoes, Cattle. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.
Is Cowlitz County a good location for home gardening?
Cowlitz County scores 63/100 (Good) 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 Cowlitz County gardeners in Zone 8a 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.
