Island County, WA — Planting Guide
Island County is in USDA Zone 8a. The average last spring frost is March 30 and the first fall frost is November 3, giving you a growing season of approximately 218 days.
At an elevation of 9 ft, Island County receives approximately 45.5 in of rainfall annually. Summer highs average 85°F with winter lows around 38°F. The predominant soil type is Silt Loam.
Based on 31 years of NOAA climate station data, the last frost date here varies by 53 days year to year — ranging from March 8 in warm years to April 30 in cold years. The growing season is trending longer by about 3.83 days per decade. Island County scores 61/100 (Good) on the Microclimate Index.
🌡️ Zone
8a (10°F to 15°F min)
❄️ Last Frost
March 30
🍂 First Frost
November 3
📅 Growing Season
218 days
⛰️ Elevation
9 ft
🌧️ Annual Rainfall
45.5 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 | 6.8 in | 19 days | — | None |
| Feb | 4.7 in | 15 days | — | Low |
| Mar | 4.5 in | 14 days | — | Low |
| Apr | 3.7 in | 12 days | 0.6 in | Moderate |
| May | 2.3 in | 10 days | 2 in | High |
| Jun | 1.6 in | 7 days | 2.7 in | High |
| Jul | 0.7 in | 3 days | 3.6 in | Critical |
| Aug | 0.8 in | 2 days | 3.5 in | Critical |
| Sep | 1.6 in | 5 days | 2.7 in | High |
| Oct | 4.2 in | 11 days | 0.1 in | Low |
| Nov | 7 in | 17 days | — | Low |
| Dec | 7.8 in | 17 days | — | None |
Annual total: 45.7 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.
Island County Soil Profile
Soil Type
Silt Loam
Soil pH
5.6-6.7
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) | Apr 30 | Nov 24 | 208 days |
| Cautious | Apr 7 | Nov 14 | 221 days |
| Average year | Mar 30 | Nov 3 | 218 days |
| Optimistic | Mar 22 | Oct 29 | 221 days |
| Aggressive (risky) | Mar 8 | Oct 11 | 217 days |
Not very — frost dates can vary by ±53 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 3.8 days per decade). Spring is arriving earlier than it used to. Good news for gardeners.
Gardening Difficulty Score
Island County offers good growing conditions. A little planning around frost dates goes a long way.
Local Gardening Help in Island 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 Island County's climate and soil.
County Extension Office
Island 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 Island County
Finding local nurseries & garden centers in Island County
Why Buy Local
Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Island 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 Island County WA" or "garden center Island 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 Island County WA" or check your extension office and local parks department. Facebook groups like "Island 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
15.8 hours
Summer solstice daylight
Shortest Day
8.2 hours
Winter solstice daylight
Peak Sun Hours
11.3 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 | 8.6 hr | 2.2 hr | Short day |
| February | 10 hr | 3.1 hr | Short day |
| March | 11.6 hr | 4 hr | Short day |
| April | 13.4 hr | 5.7 hr | Neutral |
| May | 15 hr | 7.5 hr | Long day |
| June | 15.8 hr | 8.4 hr | Long day |
| July | 15.5 hr | 11.3 hr | Long day |
| August | 14.1 hr | 9.4 hr | Long day |
| September | 12.3 hr | 6.9 hr | Neutral |
| October | 10.5 hr | 4 hr | Short day |
| November | 9 hr | 2.2 hr | Short day |
| December | 8.2 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 Apr through Oct.
Best Month to Compost
May
Microbial activity peaks when soil is warm.
Active Composting
9 months
Nearly year-round composting.
View detailed monthly data
| Month | Soil 4" Deep | Soil 8" Deep | Compost Activity | Time to Finish |
|---|---|---|---|---|
| Jan | 44°F | 51°F | 🐢 Slow | ~24 weeks |
| Feb | 44°F | 50°F | 🐢 Slow | ~24 weeks |
| Mar | 51°F | 52°F | ♻️ Active | ~14 weeks |
| Apr | 62°F | 60°F | ♻️ Active | ~14 weeks |
| May | 69°F | 68°F | 🔥 Peak | ~8 weeks |
| Jun | 79°F | 77°F | 🔥 Peak | ~8 weeks |
| Jul | 88°F | 84°F | 🔥 Peak | ~8 weeks |
| Aug | 89°F | 84°F | 🔥 Peak | ~8 weeks |
| Sep | 82°F | 83°F | 🔥 Peak | ~8 weeks |
| Oct | 74°F | 74°F | 🔥 Peak | ~8 weeks |
| Nov | 60°F | 65°F | ♻️ Active | ~14 weeks |
| Dec | 50°F | 55°F | 🐢 Slow | ~24 weeks |
Highlighted rows = soil 60°F+ (safe for warm-season transplants). Compost finishes fastest during peak activity months.
Pest & Disease Pressure in Island 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 | High | 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 | Low | 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 Island 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 4 | Sep 8 | — | Rapid growth, attracts pollinators, suppresses weeds |
| Cowpeas (southern peas) | Apr 10 | Aug 25 | ✓ Yes | Excellent nitrogen fixer for warm climates, edible |
| Sorghum-sudan grass | Apr 9 | Aug 25 | — | Massive biomass, breaks compaction, suppresses nematodes |
| White clover | Feb 28 | 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 23 | Oct 13 | — | 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 | Sep 9 | Mar 16 | ✓ Yes | Fixes nitrogen, good for heavy clay soils |
| Crimson clover | Sep 10 | Mar 9 | ✓ Yes | Fixes nitrogen, attracts pollinators in spring |
| Daikon radish | Sep 9 | Mar 9 | — | Deep taproot breaks compaction, excellent for clay soils |
| Hairy vetch | Aug 26 | Mar 16 | ✓ Yes | Excellent nitrogen fixer, good for depleted soils |
| Oats | Sep 29 | Mar 16 | — | Quick biomass, winterkills in cold zones — no spring tillage needed |
| Winter rye | Jul 26 | Mar 16 | — | Suppresses weeds, prevents erosion, breaks up compacted soil |
| Winter wheat | Aug 7 | Mar 9 | — | 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: 10 mph
Fall: 9 mph Winter: 14 mph
Prevailing wind: SW. Moderate wind — consider a temporary windbreak for young seedlings.
Windbreak Benefit
7.1/10
Strongly recommended — a windbreak (fence, hedge, or row of tall crops like corn or sunflowers) will significantly improve garden yields.
Frost Pocket Risk
Low
Relatively flat terrain (390 ft range). Frost pocket risk is minimal — garden placement is flexible.
Rainwater Harvesting Potential
How much water you can collect, when to collect it, and what size system you need for your garden.
Annual Collection
22,776 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, Feb, 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 45.7 inches of rain per year
- A 1,000 sq ft roof can collect roughly 22,776 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 Island County
Soil Type
Silt Loam
Soil pH 5.6–6.7 · Moderately Well Drained drainage
Native soil is well-suited to most vegetables and herbs with regular compost additions.
Watering Needs
Drought stress: 3.5/10
Low-to-moderate drought stress. Plan to water 1–2 times per week during peak summer. (45.5 in. annual rainfall)
Season Tips
218-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 Island County
115 vegetables that grow well in Zone 8a with planting dates for Island County.
Show all 115 vegetables with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Acorn Squash | Mar 2 | Apr 6 | Apr 13 | Jul 6 – Aug 10 | 80–100 |
| Amaranth | Feb 9 | Apr 6 | Apr 13 | Jul 13 – Aug 31 | 90–120 |
| Artichoke | — | — | Apr 13 | Aug 17 – Oct 26 | 120–180 |
| Arugula | Feb 23 | Mar 16 | Mar 30 | May 4 – Jul 6 | 30–50 |
| Asparagus | — | — | Apr 13 | — | 730–1095 |
| Beets | — | Mar 16 | — | May 11 – Jun 8 | 50–70 |
| Belgian Endive | Feb 23 | Mar 16 | Mar 30 | Jul 20 – Sep 14 | 110–150 |
| Bitter Melon | Feb 9 | Apr 6 | Apr 13 | Jun 15 – Jul 27 | 60–90 |
| Black Beans | — | Apr 6 | — | Jul 6 – Aug 24 | 90–120 |
| Bok Choy | Feb 23 | Mar 16 | Mar 30 | May 11 – Jun 15 | 40–60 |
| Broccoli | Feb 23 | Mar 16 | Mar 30 | Jun 1 – Jul 13 | 60–90 |
| Broccoli Rabe | Feb 23 | Mar 16 | Mar 30 | May 11 – Jun 15 | 40–60 |
| Brussels Sprouts | Feb 23 | Mar 16 | Mar 30 | Jun 29 – Aug 24 | 90–130 |
| Butternut Squash | Mar 2 | Apr 6 | Apr 13 | Jul 13 – Aug 17 | 85–110 |
| Cabbage | Feb 23 | Mar 16 | Mar 30 | Jun 1 – Jul 27 | 60–100 |
| Calabash | Feb 9 | Apr 6 | Apr 13 | Jul 6 – Aug 31 | 80–120 |
| Cardoon | — | — | Apr 13 | Aug 17 – Sep 28 | 120–150 |
| Carrots | — | Mar 16 | — | May 18 – Jun 22 | 60–80 |
| Cauliflower | Feb 23 | Mar 16 | Mar 30 | May 25 – Jul 27 | 55–100 |
| Celeriac | Feb 23 | Mar 16 | Mar 30 | Jul 13 – Aug 17 | 100–120 |
| Celery | Feb 23 | Mar 16 | Mar 30 | Jun 22 – Aug 17 | 80–120 |
| Celtuce | Feb 23 | Mar 16 | Mar 30 | Jun 1 – Jul 13 | 60–90 |
| Chard | Feb 23 | Mar 16 | Mar 30 | May 25 – Jul 13 | 50–60 |
| Chayote | Feb 9 | Apr 6 | Apr 13 | Aug 17 – Oct 26 | 120–180 |
| Chickpeas | Feb 23 | Mar 16 | Mar 30 | Jun 22 – Aug 3 | 80–110 |
| Chicory | Feb 23 | Mar 16 | Mar 30 | Jun 1 – Jul 13 | 60–85 |
| Chinese Cabbage | Feb 23 | Mar 16 | Mar 30 | May 25 – Jun 22 | 50–70 |
| Christmas Lima Beans | Feb 9 | Apr 6 | Apr 13 | Jul 6 – Aug 10 | 80–100 |
| Collard Greens | Feb 23 | Mar 16 | Mar 30 | May 25 – Jul 27 | 55–75 |
| Corn | — | Apr 6 | — | Jun 8 – Aug 3 | 60–100 |
| Cowpeas | — | Apr 6 | — | Jun 8 – Jul 20 | 60–90 |
| Cress | Feb 23 | Mar 16 | Mar 30 | Apr 13 – May 4 | 14–21 |
| Crookneck Squash | Mar 2 | Apr 6 | Apr 13 | Jun 1 – Jun 29 | 45–60 |
| Crosne | — | Mar 16 | — | Aug 17 – Oct 19 | 150–200 |
| Cucumber | Mar 2 | Apr 6 | Apr 13 | Jun 8 – Aug 3 | 50–70 |
| Daikon | — | Mar 16 | — | May 11 – Jun 8 | 50–70 |
| Delicata Squash | Mar 2 | Apr 6 | Apr 13 | Jul 6 – Aug 10 | 80–100 |
| Edamame | — | Apr 6 | — | Jun 22 – Aug 3 | 75–100 |
| Eggplant | Jan 26 | Apr 6 | Apr 13 | Jun 22 – Aug 24 | 65–85 |
| Endive | Feb 23 | Mar 16 | Mar 30 | May 18 – Jun 22 | 45–65 |
| Escarole | Feb 23 | Mar 16 | Mar 30 | May 25 – Jun 22 | 50–70 |
| Fava Beans | Feb 23 | Mar 16 | Mar 30 | Jun 15 – Jul 27 | 75–100 |
| Fennel | Feb 9 | Apr 6 | Apr 13 | Jun 15 – Jul 27 | 60–90 |
| Garlic | — | — | — | — | 90–240 |
| Ginger | Feb 9 | Apr 6 | Apr 13 | Dec 14 – Dec 28 | 240–300 |
| Green Beans | — | Apr 6 | — | Jun 1 – Jul 27 | 50–65 |
| Horseradish | — | — | Apr 13 | Aug 17 – Oct 26 | 120–180 |
| Hot Peppers | Jan 26 | Apr 6 | Apr 13 | Jun 22 – Sep 28 | 70–120 |
| Hubbard Squash | Mar 2 | Apr 6 | Apr 13 | Jul 27 – Aug 31 | 100–120 |
| Jicama | Feb 9 | Apr 6 | Apr 13 | Aug 17 – Oct 26 | 120–180 |
| Kabocha | Mar 2 | Apr 6 | Apr 13 | Jul 13 – Aug 10 | 85–100 |
| Kai Lan | Feb 23 | Mar 16 | Mar 30 | May 18 – Jun 15 | 45–60 |
| Kale | Feb 23 | Mar 16 | Mar 30 | May 25 – Jul 20 | 50–70 |
| Kidney Beans | — | Apr 6 | — | Jul 6 – Aug 10 | 85–110 |
| Kohlrabi | Feb 23 | Mar 16 | Mar 30 | May 18 – Jun 22 | 45–65 |
| Komatsuna | Feb 23 | Mar 16 | Mar 30 | May 4 – Jun 8 | 35–50 |
| Leeks | Feb 23 | Mar 16 | Mar 30 | Jun 29 – Sep 14 | 90–150 |
| Lentils | Feb 23 | Mar 16 | Mar 30 | Jun 22 – Aug 3 | 80–110 |
| Lettuce | Feb 23 | Mar 16 | Mar 30 | May 4 – Jul 13 | 30–60 |
| Lima Beans | — | Apr 6 | — | Jun 8 – Jul 20 | 60–90 |
| Loofah | Feb 9 | Apr 6 | Apr 13 | Jul 27 – Sep 28 | 100–150 |
| Luffa | Feb 9 | Apr 6 | Apr 13 | Jul 13 – Sep 28 | 90–150 |
| Mache | Feb 23 | Mar 16 | Mar 30 | May 11 – Jun 15 | 40–60 |
| Malabar Spinach | Feb 9 | Apr 6 | Apr 13 | Jun 8 – Jul 6 | 55–70 |
| Melon | Mar 2 | Apr 6 | Apr 13 | Jun 22 – Aug 10 | 70–100 |
| Microgreens | Feb 23 | Mar 16 | Mar 30 | Apr 6 – May 4 | 7–21 |
| Mitsuba | Feb 23 | Mar 16 | Mar 23 | May 18 – Jul 13 | 50–70 |
| Mizuna | Feb 23 | Mar 16 | Mar 30 | May 4 – Jun 1 | 30–45 |
| Mustard Greens | Feb 23 | Mar 16 | Mar 30 | May 4 – Jul 6 | 30–50 |
| Napa Cabbage | Feb 23 | Mar 16 | Mar 30 | May 25 – Jun 29 | 55–75 |
| New Zealand Spinach | Feb 9 | Apr 6 | Apr 13 | Jun 8 – Jul 6 | 55–70 |
| Okra | Feb 9 | Apr 6 | Apr 13 | Jun 8 – Aug 3 | 50–65 |
| Onion | Feb 23 | Mar 16 | Mar 30 | Jun 29 – Aug 17 | 90–120 |
| Pac Choi | Feb 23 | Mar 16 | Mar 30 | May 11 – Jun 8 | 40–55 |
| Parsnip | — | Mar 16 | — | Jun 29 – Aug 10 | 100–130 |
| Patty Pan Squash | Mar 2 | Apr 6 | Apr 13 | Jun 1 – Jun 29 | 45–60 |
| Peas | Feb 23 | Mar 16 | Mar 30 | May 25 – Jul 20 | 55–70 |
| Peppers | Jan 26 | Apr 6 | Apr 13 | Jun 15 – Aug 24 | 60–90 |
| Pole Beans | Feb 9 | Apr 6 | Apr 13 | Jun 8 – Aug 3 | 55–70 |
| Potatoes | Feb 9 | Apr 6 | Apr 13 | Jun 22 – Aug 31 | 70–120 |
| Pumpkin | Mar 2 | Apr 6 | Apr 13 | Jul 13 – Aug 31 | 85–120 |
| Purslane | Feb 23 | Mar 16 | Mar 30 | May 11 – Jun 15 | 40–60 |
| Radicchio | Feb 23 | Mar 16 | Mar 30 | Jun 1 – Jul 6 | 60–80 |
| Radish | — | Mar 16 | — | Apr 13 – May 4 | 22–35 |
| Rhubarb | — | — | Apr 20 | — | 365–730 |
| Romanesco | Feb 23 | Mar 16 | Mar 30 | Jun 15 – Jul 27 | 75–100 |
| Rutabaga | — | Mar 16 | — | Jun 8 – Jul 13 | 80–100 |
| Salsify | — | Mar 16 | — | Jun 29 – Aug 10 | 100–130 |
| Savoy Cabbage | Feb 23 | Mar 16 | Mar 30 | Jun 8 – Aug 3 | 70–110 |
| Scallions | Feb 23 | Mar 16 | Mar 30 | May 25 – Jun 22 | 50–70 |
| Scarlet Runner Beans | Feb 9 | Apr 6 | Apr 13 | Jun 15 – Jul 20 | 60–80 |
| Shallot | Feb 23 | Mar 16 | Mar 30 | Jun 29 – Aug 17 | 90–120 |
| Shiso | Feb 9 | Apr 6 | Apr 13 | Jun 8 – Aug 3 | 50–70 |
| Snap Peas | Feb 9 | Apr 6 | Apr 13 | Jun 8 – Aug 3 | 55–70 |
| Snow Peas | Feb 23 | Mar 16 | Mar 30 | May 25 – Jul 20 | 50–65 |
| Soybeans | — | Apr 6 | — | Jun 29 – Aug 24 | 80–120 |
| Spaghetti Squash | Mar 2 | Apr 6 | Apr 13 | Jul 13 – Aug 10 | 85–100 |
| Spinach | Feb 23 | Mar 16 | Mar 30 | May 4 – Jul 6 | 35–50 |
| Squash (Summer) | Mar 2 | Apr 6 | Apr 13 | Jun 1 – Aug 3 | 45–65 |
| Squash (Winter) | Mar 2 | Apr 6 | Apr 13 | Jul 6 – Aug 31 | 80–120 |
| Sunchoke | — | — | Apr 13 | Aug 3 – Sep 28 | 110–150 |
| Sunflower | Feb 9 | Apr 6 | Apr 13 | Jun 22 – Aug 10 | 70–100 |
| Sweet Corn | — | Apr 6 | — | Jun 8 – Jul 20 | 60–90 |
| Sweet Potatoes | Feb 9 | Apr 6 | Apr 13 | Jul 13 – Aug 31 | 90–120 |
| Tatsoi | Feb 23 | Mar 16 | Mar 30 | May 4 – Jun 8 | 35–50 |
| Tomatillo | Feb 9 | Apr 6 | Apr 13 | Jun 15 – Aug 24 | 60–85 |
| Tomatoes | Feb 9 | Apr 6 | Apr 13 | Jun 15 – Aug 24 | 60–85 |
| Turmeric | Feb 9 | Apr 6 | Apr 13 | Dec 14 – Dec 28 | 240–300 |
| Turnip | — | Mar 16 | — | Apr 27 – Jun 1 | 40–60 |
| Watercress | Feb 23 | Mar 16 | Mar 30 | May 11 – Jun 15 | 40–60 |
| Watermelon | Mar 2 | Apr 6 | Apr 13 | Jun 22 – Aug 10 | 70–100 |
| Wax Beans | — | Apr 6 | — | Jun 1 – Jul 27 | 50–65 |
| Winter Melon | Feb 9 | Apr 6 | Apr 13 | Jul 13 – Aug 31 | 90–120 |
| Yard Long Beans | Feb 9 | Apr 6 | Apr 13 | Jun 8 – Jul 20 | 55–80 |
| Zucchini | Mar 2 | Apr 6 | Apr 13 | Jun 1 – Jul 27 | 45–60 |
🍓 Fruits to Grow in Island County
27 fruits that grow well in Zone 8a with planting dates for Island County.
Show all 27 fruits with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Alpine Strawberries | — | — | Apr 20 | Jul 20 – Nov 2 | 90–180 |
| Aronia | — | — | Apr 20 | — | 730–1095 |
| Blackberries | — | — | Apr 20 | — | 365–730 |
| Blueberries | — | — | Apr 20 | — | 730–1095 |
| Boysenberries | — | — | Apr 20 | — | 365–730 |
| Cantaloupe | — | — | Apr 20 | Jun 29 – Aug 3 | 70–90 |
| Che Fruit | — | — | Apr 20 | — | 1095–1825 |
| Elderberries | — | — | Apr 20 | — | 730–1095 |
| Figs | — | — | Apr 20 | — | 730–1825 |
| Goji Berries | — | — | Apr 20 | — | 730–1095 |
| Gooseberries | — | — | Apr 20 | — | 730–1095 |
| Grapes | — | — | Apr 20 | — | 730–1095 |
| Ground Cherry | — | — | Apr 20 | Jun 29 – Aug 24 | 65–80 |
| Hardy Kiwi | — | — | Apr 20 | — | 1095–1825 |
| Honeydew | — | — | Apr 20 | Jul 13 – Aug 24 | 80–110 |
| Jostaberry | — | — | Apr 20 | — | 730–1095 |
| Kiwi | — | — | Apr 20 | — | 1095–1825 |
| Loquat | — | — | Apr 20 | — | 730–1825 |
| Medlar | — | — | Apr 20 | — | 1095–1825 |
| Mulberries | — | — | Apr 20 | — | 730–1825 |
| Pawpaw | — | — | Apr 20 | — | 1095–2555 |
| Persimmon | — | — | Apr 20 | — | 1095–2555 |
| Pomegranate | — | — | Apr 20 | — | 730–1095 |
| Quince | — | — | Apr 20 | — | 1095–1825 |
| Raspberries | — | — | Apr 20 | — | 365–730 |
| Serviceberries | — | — | Apr 20 | — | 730–1095 |
| Strawberries | — | — | Apr 20 | Jul 20 – Jan 4 | 90–365 |
🌿 Herbs to Grow in Island County
42 herbs that grow well in Zone 8a with planting dates for Island County.
Show all 42 herbs with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Angelica | Feb 23 | Mar 16 | Mar 23 | — | 365–730 |
| Anise | Feb 23 | Mar 16 | Mar 23 | Jun 22 – Sep 7 | 90–120 |
| Basil | Feb 9 | Apr 6 | Apr 13 | Jun 8 – Aug 10 | 50–75 |
| Bee Balm | — | — | Apr 6 | Jul 6 – Sep 21 | 90–120 |
| Borage | Feb 23 | Mar 16 | Mar 23 | May 18 – Jul 6 | 50–60 |
| Caraway | Feb 23 | Mar 16 | Mar 23 | — | 365–450 |
| Catnip | — | — | Apr 6 | Jun 8 – Aug 10 | 60–80 |
| Chamomile | Feb 23 | Mar 16 | Mar 23 | May 25 – Aug 3 | 60–90 |
| Chervil | Feb 23 | Mar 16 | Mar 23 | May 4 – Jul 6 | 40–60 |
| Chives | — | — | Apr 6 | Jun 8 – Aug 17 | 60–90 |
| Cilantro | Feb 23 | Mar 16 | Mar 23 | May 4 – Jul 6 | 40–60 |
| Comfrey | — | — | Apr 6 | Jun 8 – Aug 17 | 60–90 |
| Cumin | Feb 23 | Mar 16 | Mar 23 | Jul 6 – Sep 7 | 100–120 |
| Dill | Feb 23 | Mar 16 | Mar 23 | May 4 – Jul 6 | 40–60 |
| Echinacea | — | — | Apr 6 | Aug 10 – Nov 16 | 120–180 |
| Epazote | Feb 9 | Apr 6 | Apr 13 | Jun 1 – Jul 27 | 45–60 |
| Fennel (herb) | Feb 23 | Mar 16 | Mar 23 | May 25 – Aug 3 | 60–90 |
| Feverfew | — | — | Apr 6 | Jul 6 – Sep 21 | 90–120 |
| Garlic Chives | — | — | Apr 6 | Jun 8 – Aug 17 | 60–90 |
| Horehound | — | — | Apr 6 | Jun 22 – Aug 17 | 75–90 |
| Hyssop | — | — | Apr 6 | Jun 15 – Aug 17 | 70–90 |
| Lavender | — | — | Apr 6 | Jul 6 – Dec 7 | 90–200 |
| Lemon Balm | — | — | Apr 6 | Jun 8 – Jul 27 | 60–70 |
| Lemon Thyme | — | — | Apr 6 | Jun 15 – Aug 17 | 70–90 |
| Lemon Verbena | Feb 9 | Apr 6 | Apr 13 | Jun 15 – Aug 24 | 60–90 |
| Lemongrass | Feb 9 | Apr 6 | Apr 13 | Jun 29 – Sep 28 | 75–120 |
| Lovage | — | — | Apr 6 | Jun 15 – Aug 17 | 70–90 |
| Marjoram | — | — | Apr 6 | Jun 8 – Aug 17 | 60–90 |
| Mint | — | — | Apr 6 | Jun 8 – Aug 17 | 60–90 |
| Oregano | — | — | Apr 6 | Jun 8 – Aug 17 | 60–90 |
| Parsley | Feb 23 | Mar 16 | Mar 23 | May 25 – Jul 27 | 60–80 |
| Rosemary | — | — | Apr 6 | Jun 29 – Nov 16 | 80–180 |
| Rue | — | — | Apr 6 | Jun 15 – Aug 17 | 70–90 |
| Sage | — | — | Apr 6 | Jun 22 – Aug 17 | 75–90 |
| Savory | — | — | Apr 6 | Jun 1 – Jul 27 | 50–70 |
| Sorrel | Feb 23 | Mar 16 | Mar 23 | May 4 – Jul 6 | 40–60 |
| Stevia | Feb 9 | Apr 6 | Apr 13 | Jun 15 – Aug 24 | 60–90 |
| Tarragon | — | — | Apr 6 | Jun 8 – Aug 17 | 60–90 |
| Thai Basil | Feb 9 | Apr 6 | Apr 13 | Jun 8 – Aug 10 | 50–75 |
| Thyme | — | — | Apr 6 | Jun 15 – Aug 17 | 70–90 |
| Valerian | — | — | Apr 6 | Aug 10 – Nov 16 | 120–180 |
| Yarrow | — | — | Apr 6 | Jul 6 – Sep 21 | 90–120 |
Monthly Planting Guide for Island County
Gardening Guides & Resources
Helpful guides from The Ultimate Homestead to improve your garden in Island County.
Frequently Asked Questions
What planting zone is Island County, WA?
Island 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 Island County, WA?
Based on 31 years of NOAA weather station data, the median last spring frost in Island County falls around March 30. In 8 out of 10 years, last frost lands between March 8 and April 30 — a 53-day window of variability. Use April 30 as your conservative safe-to-plant date for frost-sensitive crops.
When is the first fall frost in Island County, WA?
The median first fall frost in Island County arrives around November 3. In cold years it can arrive as early as October 11; 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 Island County?
Island County has a frost-free growing season of approximately 218 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 3.83 days per decade.
What is the soil like in Island County for gardening?
Island County has predominantly Silt Loam soil with a pH range of 5.6–6.7 and Moderately Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.
What is grown commercially in Island County?
Island County has commercial agriculture that includes Wheat, Apples, Potatoes, Hops. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.
Is Island County a good location for home gardening?
Island County scores 61/100 (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 Island 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.
