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When to Plant Comfrey in Grant County, KS

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

Grant County, Kansas is in USDA Zone 6a. The average last spring frost is April 21 and the first fall frost is October 17, giving you a growing season of approximately 179 days.

At an elevation of 1,096 feet, Grant County receives approximately 25.2 inches of rainfall annually with predominantly loam soil. Summer highs average 85ยฐF, providing good warmth for Comfrey during the growing season.

Grant County, KS (Zone 6a) Moderate season
179 days
Last Spring Frost April 21
179 growing days
First Fall Frost October 17

Grant County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (39 days to spare)
Transplant: Apr 23 🍅 Harvest: Jun 25 – Sep 3
Recommended (50%) ✓ Fits season (39 days to spare)
Transplant: Apr 28 🍅 Harvest: Jun 30 – Sep 8
Safe Start (90%) ✓ Fits season (41 days to spare)
Transplant: May 11 🍅 Harvest: Jul 13 – Sep 21

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 781 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Comfrey needs ~1,031 GDD — county provides 2,461 GDD Excellent fit

Comfrey Planting Timeline โ€” Grant County, KS

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors April 28 Apr 28 โ€“ May 12
Harvest June 30 Jun 30 โ€“ Sep 8

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Transplant Outdoors
May Transplant Outdoors
June Harvest
July Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“90 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 6a

Growing Season

179 days

Growing Tips for Grant 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Comfrey in Grant County, KS?

Grant County is in Zone 6a with an average last frost of April 21. Plan your Comfrey planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Grant County, KS?

Grant County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 21 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Grant County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

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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 Grant County, KS. Local conditions may vary. Last updated: April 2026.