When to Plant Savoy Cabbage in King County, WA
May to-do list for King County, Washington
Here's what deserves your attention in King County, Washington this month. Everything below is tailored to Zone 9a and timed around your local frost dates.
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Indoor seed-starting week for savoy cabbage
Your window is short. These crops want several weeks of indoor growth before they go outside.
To set up a strong June, finish these tasks
- First harvests: savoy cabbage
Savoy cabbage has crinkled, deeply veined leaves that form looser heads than regular cabbage. It has a milder, sweeter flavor and is more cold-tolerant.
King County, Washington is in USDA Zone 9a. The average last spring frost is April 7 and the first fall frost is October 30, giving you a growing season of approximately 206 days.
At an elevation of 258 feet, King County receives approximately 37.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Savoy Cabbage during the growing season.
King County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.4
Drainage
Well Drained
Plant Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Soil Compatibility in King County
How your county's soil matches Savoy Cabbage's growing requirements.
Soil pH
Your soil pH (5.7–6.4) overlaps with Savoy Cabbage's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in King County is excellent for Savoy Cabbage — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.5%) — Savoy Cabbage will thrive.
How to Plant Savoy Cabbage
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Savoy Cabbage
Sow every 8 weeks. Last sowing by Jul 12 to harvest before frost.
For a dedicated fall crop, sow by Sep 04.
Plant Water Budget
Monthly Watering Guide for Savoy Cabbage
Savoy Cabbage needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Savoy Cabbage Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 5.9" | 0" | ❄️ Dormant |
| Feb | — | 4.5" | 0" | ❄️ Dormant |
| Mar | — | 3.4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| May | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Jun | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Jul | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Aug | 4.3" | 0.7" | 3.6" | 🚿 Regular watering |
| Sep | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Oct | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Nov | — | 5.6" | 0" | ❄️ Dormant |
| Dec | — | 5.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in King County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Savoy Cabbage Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Savoy Cabbage Planting Timeline — King County, WA
Savoy Cabbage Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 10 | Mar 10 – Mar 24 |
| Transplant Outdoors | April 7 | Apr 7 – Apr 21 |
| Direct Sow | March 17 | Mar 17 – Apr 7 |
| Harvest | June 16 | Jun 16 – Aug 11 |
| Fall Sowing | September 4 | Sep 4 – Sep 18 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
70–110 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 9a
📆 Growing Season
206 days in King County
Growing Tips for Savoy Cabbage in King County
Direct sow Savoy Cabbage outdoors after April 07 in King County when soil has warmed and frost danger has passed.
Common pests for Savoy Cabbage in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 4-6 weeks before last frost. Savoy cabbage is more forgiving of temperature fluctuations than smooth-leaved types. Excellent for stuffed cabbage rolls.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Savoy Cabbage in Other Locations
Frequently Asked Questions
When should I plant Savoy Cabbage in King County, WA?
King County is in Zone 9a with an average last frost of April 7. Plan your Savoy Cabbage planting based on this frost date — see the calendar above for exact timing.
What planting zone is King County, WA?
King County, Washington is in USDA Hardiness Zone 9a. The average last spring frost is April 7 and first fall frost is October 30.
Your King County Garden Planner — Free
A 24-page printable planner built for King County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.