When to Plant Kale in Clark County, WA
Kale is an exceptionally hardy, nutrient-dense green available in curly, lacinato, and Russian varieties. It tolerates heavy frost and often tastes sweeter after cold exposure.
Clark County, Washington is in USDA Zone 8a. The average last spring frost is April 14 and the first fall frost is October 27, giving you a growing season of approximately 196 days.
At an elevation of 482 feet, Clark County receives approximately 39.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Kale during the growing season.
Clark County Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.3
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 Clark County
How your county's soil matches Kale's growing requirements.
Soil pH
Your soil pH (5.4–6.3) is more acidic than Kale prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Clark County is excellent for Kale — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Kale.
Organic Matter
Organic matter is excellent (4.8%) — Kale will thrive.
How to Plant Kale
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Kale
Sow every 5.7 weeks. Last sowing by Aug 18 to harvest before frost.
For a dedicated fall crop, sow by Aug 18.
Plant Water Budget
Monthly Watering Guide for Kale
Kale needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.
| Month | Kale Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 5.4" | 0" | ❄️ Dormant |
| Feb | — | 4.6" | 0" | ❄️ Dormant |
| Mar | — | 4" | 0" | ❄️ Dormant |
| Apr | 3.5" | 2.6" | 0.9" | 💧 Light watering |
| May | 3.5" | 2.5" | 1" | 💧 Light watering |
| Jun | 3.5" | 1.7" | 1.8" | 🚿 Regular watering |
| Jul | 3.5" | 0.6" | 2.9" | 🚿 Regular watering |
| Aug | 3.5" | 0.8" | 2.7" | 🚿 Regular watering |
| Sep | 3.5" | 1.5" | 2" | 🚿 Regular watering |
| Oct | 3.5" | 3.1" | 0.4" | 💧 Light watering |
| Nov | — | 5.9" | 0" | ❄️ Dormant |
| Dec | — | 7.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Clark County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Kale 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.
Kale Planting Timeline — Clark County, WA
Kale Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 10 | Mar 10 – Mar 24 |
| Transplant Outdoors | April 14 | Apr 14 – Apr 28 |
| Direct Sow | March 31 | Mar 31 – Apr 21 |
| Harvest | June 9 | Jun 9 – Aug 4 |
| Fall Sowing | August 18 | Aug 18 – Sep 1 |
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 | Fall Sowing Harvest |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · Only during dry spells
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 8a
📆 Growing Season
196 days in Clark County
Growing Tips for Kale in Clark County
Direct sow Kale outdoors after April 14 in Clark County when soil has warmed and frost danger has passed.
Common pests for Kale in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow or transplant in early spring or late summer. Harvest outer leaves first to keep plants productive. Kale overwinters in many climates and can provide greens all year.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Isolate 1/2 mile from other brassicas (broccoli, cabbage, etc.) — they all cross.
Kale in Other Locations
Frequently Asked Questions
When should I plant Kale in Clark County, WA?
Clark County is in Zone 8a with an average last frost of April 14. Plan your Kale planting based on this frost date — see the calendar above for exact timing.
What planting zone is Clark County, WA?
Clark County, Washington is in USDA Hardiness Zone 8a. The average last spring frost is April 14 and first fall frost is October 27.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Clark County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.
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