When to plant Comfrey in St. Clair County County,
St. Clair County County's short 201-day growing season means one Comfrey planting between April 15 and April 29. No fall crop in Zone 6b.
When to Plant Comfrey in St. Clair County, MO
Your June planting checklist for St. Clair County, Missouri
Each item below is timed to St. Clair County, Missouri's frost dates and soil temperatures. Skip nothing, stress about nothing.
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Harvest comfrey as they ripen
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
July prep starts now
- First harvests: comfrey
Comfrey is a vigorous perennial herb valued as a dynamic accumulator of nutrients. Its leaves make excellent mulch, compost activator, and liquid fertilizer.
St. Clair County, Missouri is in USDA Zone 6b. The average last spring frost is April 8 and the first fall frost is October 26, giving you a growing season of approximately 201 days.
At an elevation of 699 feet, St. Clair County receives approximately 41.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Comfrey during the growing season.
St. Clair County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.7
Drainage
Well Drained
Comfrey 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 St. Clair County
How your county's soil matches Comfrey's growing requirements.
Soil pH
Your soil pH (5.5–6.7) overlaps with Comfrey's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in St. Clair County is excellent for Comfrey — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Comfrey.
Organic Matter
Organic matter is moderate (2.9%). Annual compost additions will help Comfrey.
How to Plant Comfrey
Succession Planting Comfrey
Sow every 6.9 weeks. Last sowing by Jul 28 to harvest before frost.
Comfrey 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 | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 5.2" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Sep | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Oct | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Nov | — | 2.9" | 0" | ❄️ Dormant |
| Dec | — | 2.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in St. Clair 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 — St. Clair County, MO
Comfrey Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 15 | Apr 15 – Apr 29 |
| Harvest | June 17 | Jun 17 – Aug 26 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 6b
📆 Growing Season
201 days in St. Clair County
Growing Tips for Comfrey in St. Clair County
Direct sow Comfrey outdoors after April 08 in St. Clair County when soil has warmed and frost danger has passed.
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 St. Clair County, MO?
St. Clair County is in Zone 6b with an average last frost of April 8. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.
What planting zone is St. Clair County, MO?
St. Clair County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 8 and first fall frost is October 26.
When should I plant Comfrey in St. Clair County County, ?
In St. Clair County County, , plant Comfrey after the last frost (around April 8) and before the first frost (around October 26). Best results when soil holds above 50°F.
What growing zone is St. Clair County County, for Comfrey?
St. Clair County County sits in USDA Zone 6b. Comfrey grows reliably in zones 3a through 9b, so it's a good fit here.
Can Comfrey grow in St. Clair County County's climate?
Yes — Comfrey grows well in St. Clair County County's temperate climate. St. Clair County County averages a 201-day frost-free season, with last frost around April 8 and first frost around October 26.
Your St. Clair County Garden Planner — Free
A 22-page printable planner built for St. Clair County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.