When to Plant Beets in King County, WA
Beets are a dual-purpose root vegetable with edible roots and nutritious greens. They come in red, golden, and striped varieties and are rich in vitamins and minerals.
King County, Washington is in USDA Zone 8b. 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 Beets 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 Beets's growing requirements.
Soil pH
Your soil pH (5.7–6.4) overlaps with Beets's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in King County is excellent for Beets — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.5%) — Beets will thrive.
How to Plant Beets
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Beets
Sow every 5.7 weeks. Last sowing by Aug 21 to harvest before frost.
For a dedicated fall crop, sow by Aug 21.
Plant Water Budget
Monthly Watering Guide for Beets
Beets 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 | Beets Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 5.9" | 0" | ❄️ Dormant |
| Feb | — | 4.5" | 0" | ❄️ Dormant |
| Mar | — | 3.4" | 0" | ❄️ Dormant |
| Apr | 3.5" | 2.9" | 0.6" | 💧 Light watering |
| May | 3.5" | 2" | 1.5" | 💧 Light watering |
| Jun | 3.5" | 1.3" | 2.2" | 🚿 Regular watering |
| Jul | 3.5" | 0.6" | 2.9" | 🚿 Regular watering |
| Aug | 3.5" | 0.7" | 2.8" | 🚿 Regular watering |
| Sep | 3.5" | 1.6" | 1.9" | 🚿 Regular watering |
| Oct | 3.5" | 3.4" | 0.1" | 💧 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.
Beets 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.
Beets Planting Timeline — King County, WA
Beets Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | March 24 | Mar 24 – Apr 14 |
| Harvest | May 19 | May 19 – Jun 16 |
| Fall Sowing | August 21 | Aug 21 – Sep 4 |
Plant 0.5" deep · 4" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Direct Sow |
| April | Direct Sow |
| May | Harvest |
| June | Harvest |
| July | — |
| August | Fall Sowing |
| 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: acceptable
🗺️ USDA Zone
Zone 8b
📆 Growing Season
206 days in King County
Growing Tips for Beets in King County
Direct sow Beets outdoors after April 07 in King County when soil has warmed and frost danger has passed.
General growing tips
Soak seeds overnight before planting to improve germination. Thin seedlings to 3-4 inches apart. Harvest roots when 1.5-3 inches in diameter for best texture.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Isolate 1/2 mile from Swiss chard — same species, they will cross.
Beets in Other Locations
Frequently Asked Questions
When should I plant Beets in King County, WA?
King County is in Zone 8b with an average last frost of April 7. Plan your Beets 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 8b. The average last spring frost is April 7 and first fall frost is October 30.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help King County gardeners in Zone 8b organize planting dates, track what's growing, and never miss a planting window.
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