When to Plant Beets in San Juan County, WA
Your May planting checklist for San Juan County, Washington
A quick May briefing for San Juan County, Washington gardeners — what's urgent, what's next, and what can wait.
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Collect beets at their peak
If you can't use it all right away, check the food-preservation section of your planner.
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.
San Juan County, Washington is in USDA Zone 9a. The average last spring frost is March 26 and the first fall frost is November 3, giving you a growing season of approximately 222 days.
At an elevation of 371 feet, San Juan County receives approximately 40.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82°F, so choose short-season varieties of Beets to ensure they mature before fall.
San Juan County Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.4
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 San Juan County
How your county's soil matches Beets's growing requirements.
Soil pH
Your soil pH (5.4–6.4) is more acidic than Beets prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in San Juan County is excellent for Beets — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Beets.
Organic Matter
Organic matter is excellent (4.8%) — Beets will thrive.
How to Plant Beets
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Beets
Sow every 5.7 weeks. Last sowing by Aug 25 to harvest before frost.
For a dedicated fall crop, sow by Sep 08.
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 | — | 5.7" | 0" | ❄️ Dormant |
| Feb | — | 4.7" | 0" | ❄️ Dormant |
| Mar | 3.5" | 4.1" | 0" | ✅ Rainfall sufficient |
| Apr | 3.5" | 2.6" | 0.9" | 💧 Light watering |
| May | 3.5" | 2.6" | 0.9" | 💧 Light watering |
| Jun | 3.5" | 1.5" | 2" | 🚿 Regular watering |
| Jul | 3.5" | 0.6" | 2.9" | 🚿 Regular watering |
| Aug | 3.5" | 0.8" | 2.7" | 🚿 Regular watering |
| Sep | 3.5" | 1.8" | 1.7" | 💧 Light watering |
| Oct | 3.5" | 3.4" | 0.1" | 💧 Light watering |
| Nov | 3.5" | 6.4" | 0" | ✅ Rainfall sufficient |
| Dec | — | 6.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in San Juan 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 — San Juan County, WA
Beets Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | March 5 | Mar 5 – Mar 26 |
| Harvest | April 30 | Apr 30 – May 28 |
| Fall Sowing | September 8 | Sep 8 – Sep 22 |
Plant 0.5" deep · 4" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Direct Sow |
| April | Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| 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 9a
📆 Growing Season
222 days in San Juan County
Growing Tips for Beets in San Juan County
Direct sow Beets outdoors after March 26 in San Juan 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 San Juan County, WA?
San Juan County is in Zone 9a with an average last frost of March 26. Plan your Beets planting based on this frost date — see the calendar above for exact timing.
What planting zone is San Juan County, WA?
San Juan County, Washington is in USDA Hardiness Zone 9a. The average last spring frost is March 26 and first fall frost is November 3.
Your San Juan County Garden Planner — Free
A 24-page printable planner built for San Juan 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.