When to Plant Comfrey in Pend Oreille County, WA
Comfrey is a vigorous perennial herb valued as a dynamic accumulator of nutrients. Its leaves make excellent mulch, compost activator, and liquid fertilizer.
Pend Oreille County, Washington is in USDA Zone 5b. The average last spring frost is May 10 and the first fall frost is September 23, giving you a growing season of approximately 136 days.
At an elevation of 3,807 feet, Pend Oreille County receives approximately 13.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Comfrey during the growing season. With low rainfall, drip irrigation is essential for growing Comfrey successfully. Mulch heavily to conserve soil moisture.
Pend Oreille County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-6.6
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 Pend Oreille County
How your county's soil matches Comfrey's growing requirements.
Soil pH
Your soil pH (5.3–6.6) is more acidic than Comfrey prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Pend Oreille County is excellent for Comfrey — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Comfrey.
Organic Matter
Organic matter is excellent (5.0%) — Comfrey will thrive.
How to Plant Comfrey
Succession Planting Comfrey
Sow every 6.9 weeks. Last sowing by Jun 25 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Comfrey
Comfrey needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Comfrey Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 1.3" | 0" | ❄️ Dormant |
| Apr | — | 0.9" | 0" | ❄️ Dormant |
| May | 4.3" | 0.8" | 3.5" | 🚿 Regular watering |
| Jun | 4.3" | 0.5" | 3.8" | 🚿 Regular watering |
| Jul | 4.3" | 0.2" | 4.1" | 🚿 Regular watering |
| Aug | 4.3" | 0.2" | 4.1" | 🚿 Regular watering |
| Sep | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Oct | — | 1.3" | 0" | ❄️ Dormant |
| Nov | — | 2.1" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Pend Oreille County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Comfrey 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.
Comfrey Planting Timeline — Pend Oreille County, WA
Comfrey Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 17 | May 17 – May 31 |
| Harvest | July 19 | Jul 19 – Sep 27 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · 2-3 times/week
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 5b
📆 Growing Season
136 days in Pend Oreille County
Growing Tips for Comfrey in Pend Oreille County
Direct sow Comfrey outdoors after May 10 in Pend Oreille County when soil has warmed and frost danger has passed.
Pend Oreille County receives only 13" of rain annually. Comfrey needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Plant root cuttings 2 inches deep. Choose Bocking 14 variety to prevent self-seeding. Cut leaves 3-4 times per season for mulch or compost. Avoid planting near pathways as it spreads.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Comfrey in Other Locations
Frequently Asked Questions
When should I plant Comfrey in Pend Oreille County, WA?
Pend Oreille County is in Zone 5b with an average last frost of May 10. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.
What planting zone is Pend Oreille County, WA?
Pend Oreille County, Washington is in USDA Hardiness Zone 5b. The average last spring frost is May 10 and first fall frost is September 23.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Pend Oreille County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
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