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When to Plant Comfrey in Robertson County, TN

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

Robertson County, Tennessee is in USDA Zone 7a. The average last spring frost is April 6 and the first fall frost is October 29, giving you a growing season of approximately 206 days.

At an elevation of 3,620 feet, Robertson County receives approximately 42.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Comfrey during the growing season.

Robertson County, TN (Zone 7a) Long season
206 days
Last Spring Frost April 6
206 growing days
First Fall Frost October 29

Robertson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-7

Drainage

Well Drained

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 3.1" 0" ❄️ Dormant
Feb 3.8" 0" ❄️ Dormant
Mar 3.7" 0" ❄️ Dormant
Apr 4.3" 3.1" 1.2" 💧 Light watering
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 3.5" 0.8" 💧 Light watering
Jul 4.3" 4.6" 0" ✅ Rainfall sufficient
Aug 4.3" 4.4" 0" ✅ Rainfall sufficient
Sep 4.3" 2.9" 1.4" 💧 Light watering
Oct 4.3" 2.9" 1.4" 💧 Light watering
Nov 3.4" 0" ❄️ Dormant
Dec 3.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Robertson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Comfrey Planting Timeline — Robertson County, TN

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors April 13 Apr 13 – Apr 27
Harvest June 15 Jun 15 – Aug 24

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

Month-by-Month Timeline

MonthActivities
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

Moderate — regular watering

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 7a

📆 Growing Season

206 days in Robertson County

Growing Tips for Robertson County

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 Robertson County, TN?

Robertson County is in Zone 7a with an average last frost of April 6. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.

What planting zone is Robertson County, TN?

Robertson County, Tennessee is in USDA Hardiness Zone 7a. The average last spring frost is April 6 and first fall frost is October 29.

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Your Robertson County Garden Planner — Free

A 24-page printable planner built for Robertson County (Zone 7a). 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 Robertson County, TN. 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.