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When to Plant Comfrey in Miami County, KS

Miami County, Kansas Zone 6b May

Your May planting checklist for Miami County, Kansas

A quick May briefing for Miami County, Kansas gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 12
Avg. first frost October 25
Soil temp (4") 64°F
Watering Moderate
Pest pressure Low
Daylight 14.1 hrs
June will be here before you know it — start on
  • First harvests: comfrey

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

Miami County, Kansas is in USDA Zone 6b. The average last spring frost is April 12 and the first fall frost is October 25, giving you a growing season of approximately 196 days.

At an elevation of 689 feet, Miami County receives approximately 21.7 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Comfrey during the growing season.

Miami County, KS (Zone 6b) Moderate season
196 days
Last Spring Frost April 12
196 growing days
First Fall Frost October 25

Miami County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (54 days to spare)
Transplant: Apr 13 🍅 Harvest: Jun 15 – Aug 24
Recommended (50%) ✓ Fits season (56 days to spare)
Transplant: Apr 19 🍅 Harvest: Jun 21 – Aug 30
Safe Start (90%) ✓ Fits season (52 days to spare)
Transplant: May 4 🍅 Harvest: Jul 6 – Sep 14

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 Miami County

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

Soil pH

Your soil pH (6.5–7.7) is more alkaline than Comfrey prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Miami County is excellent for Comfrey — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.1%) — Comfrey will thrive.

How to Plant Comfrey

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

Succession Planting Comfrey

3
successive plantings in your 196-day season

Sow every 6.9 weeks. Last sowing by Jul 27 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 933 gal / 100 sq ft

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 0.5" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 4.3" 2.1" 2.2" 🚿 Regular watering
May 4.3" 3.2" 1.1" 💧 Light watering
Jun 4.3" 3.2" 1.1" 💧 Light watering
Jul 4.3" 3" 1.3" 💧 Light watering
Aug 4.3" 2.8" 1.5" 💧 Light watering
Sep 4.3" 2.2" 2.1" 💧 Light watering
Oct 4.3" 1.5" 2.8" 🚿 Regular watering
Nov 0.6" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Miami 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 ~1,200 GDD — county provides 3,136 GDD Excellent fit

Comfrey Planting Timeline — Miami County, KS

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors April 19 Apr 19 – May 3
Harvest June 21 Jun 21 – Aug 30

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
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

196 days in Miami County

Growing Tips for Comfrey in Miami County

Direct sow Comfrey outdoors after April 12 in Miami County when soil has warmed and frost danger has passed.

Miami County receives only 22" 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 →

Frequently Asked Questions

When should I plant Comfrey in Miami County, KS?

Miami County is in Zone 6b with an average last frost of April 12. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.

What planting zone is Miami County, KS?

Miami County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 12 and first fall frost is October 25.

🌱

Your Miami County Garden Planner — Free

A 24-page printable planner built for Miami 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.

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

Sources & credits

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