Blog

When to plant Comfrey in St. Francois County County,

St. Francois County County's 188-day season only supports one Comfrey planting per year. Sow between April 23 and May 7 for the best chance at full maturity before October 21.

When to Plant Comfrey in St. Francois County, MO

St. Francois County, Missouri Zone 6b June

What to do in June

A quick June briefing for St. Francois County, Missouri gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 16
Avg. first frost October 21
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
  1. It's harvest week for comfrey

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Get ahead of July
  • First harvests: comfrey

Instant PDF download. No spam, unsubscribe any time.

Comfrey is a vigorous perennial herb valued as a dynamic accumulator of nutrients. Its leaves make excellent mulch, compost activator, and liquid fertilizer.

St. Francois County, Missouri is in USDA Zone 6b. The average last spring frost is April 16 and the first fall frost is October 21, giving you a growing season of approximately 188 days.

At an elevation of 808 feet, St. Francois County receives approximately 41 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Comfrey during the growing season.

St. Francois County, MO (Zone 6b) Moderate season
188 days
Last Spring Frost April 16
188 growing days
First Fall Frost October 21

St. Francois County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-7

Drainage

Well Drained

Comfrey Planting Risk Windows

Early Start (70% safe) ✓ Fits season (48 days to spare)
Transplant: Apr 15 🍅 Harvest: Jun 17 – Aug 26
Recommended (50%) ✓ Fits season (48 days to spare)
Transplant: Apr 23 🍅 Harvest: Jun 25 – Sep 3
Safe Start (90%) ✓ Fits season (50 days to spare)
Transplant: May 6 🍅 Harvest: Jul 8 – Sep 16

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. Francois County

How your county's soil matches Comfrey's growing requirements.

Soil pH

Your soil pH (5.3–7.0) overlaps with Comfrey's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in St. Francois 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

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Comfrey

3
successive plantings in your 188-day season

Sow every 6.9 weeks. Last sowing by Jul 23 to harvest before frost.

Comfrey Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.5" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 4.3" 4.3" 0" ✅ Rainfall sufficient
May 4.3" 5.4" 0" ✅ Rainfall sufficient
Jun 4.3" 5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.2" 0.1" 💧 Light watering
Aug 4.3" 4.6" 0" ✅ Rainfall sufficient
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 3.6" 0.7" 💧 Light watering
Nov 2.9" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in St. Francois 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 needs ~1,369 GDD — county provides 3,431 GDD Excellent fit

Comfrey Planting Timeline — St. Francois County, MO

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors April 23 Apr 23 – May 7
Harvest June 25 Jun 25 – Sep 3

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Transplant Outdoors
May Transplant Outdoors
June Harvest
July Harvest
August Harvest
September Harvest
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

188 days in St. Francois County

Growing Tips for Comfrey in St. Francois County

Direct sow Comfrey outdoors after April 16 in St. Francois 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 →

Frequently Asked Questions

When should I plant Comfrey in St. Francois County, MO?

St. Francois County is in Zone 6b with an average last frost of April 16. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. Francois County, MO?

St. Francois County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 16 and first fall frost is October 21.

When should I plant Comfrey in St. Francois County County, ?

In St. Francois County County, , plant Comfrey after the last frost (around April 16) and before the first frost (around October 21). Best results when soil holds above 50°F.

What growing zone is St. Francois County County, for Comfrey?

St. Francois 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. Francois County County's climate?

Yes — Comfrey grows well in St. Francois County County's temperate climate. St. Francois County County averages a 188-day frost-free season, with last frost around April 16 and first frost around October 21.

🌱

Your St. Francois County Garden Planner — Free

A 22-page printable planner built for St. Francois 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for St. Francois County, MO. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.