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When to plant Comfrey in Gilpin County, CO

Gilpin County's short 135-day growing season means one Comfrey planting between May 21 and June 4. No fall crop in Zone 5b.

When to Plant Comfrey in Gilpin County, CO

Gilpin County, Colorado Zone 5b July

July to-do list for Gilpin County, Colorado

If you only do a handful of things in the garden this July, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 14
Avg. first frost September 26
Soil temp (4") 55°F
Watering High
Pest pressure High
Daylight 14.6 hrs
  1. Harvest comfrey as they ripen

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Looking ahead to August
  • 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.

Gilpin County, Colorado is in USDA Zone 5b. The average last spring frost is May 14 and the first fall frost is September 26, giving you a growing season of approximately 135 days.

At an elevation of 6,444 feet, Gilpin County receives approximately 18.6 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Comfrey to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Comfrey successfully. Mulch heavily to conserve soil moisture.

Gilpin County, CO (Zone 5b) Short season
135 days
Last Spring Frost May 14
135 growing days
First Fall Frost September 26

Gilpin County Soil Profile

Soil Type

Loam

Soil pH

6.8-8

Drainage

Well Drained

Comfrey Planting Risk Windows

Early Start (70% safe) ✓ Fits season (0 days to spare)
Transplant: May 10 🍅 Harvest: Jul 12 – Sep 20
Recommended (50%) ✗ May not fit
Transplant: May 21 🍅 Harvest: Jul 23 – Oct 1
Safe Start (90%) ✗ May not fit
Transplant: Jun 17 🍅 Harvest: Aug 19 – Oct 28

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 Gilpin County

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

Soil pH

Your soil pH (6.8–8.0) is more alkaline than Comfrey prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Comfrey.

How to Plant Comfrey

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

Succession Planting Comfrey

2
successive plantings in your 135-day season

Sow every 6.9 weeks. Last sowing by Jun 28 to harvest before frost.

Comfrey 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 607 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 1.4" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 2.1" 0" ❄️ Dormant
May 4.3" 1.8" 2.5" 🚿 Regular watering
Jun 4.3" 1.4" 2.9" 🚿 Regular watering
Jul 4.3" 1.7" 2.6" 🚿 Regular watering
Aug 4.3" 2.1" 2.2" 🚿 Regular watering
Sep 4.3" 1.3" 3" 🚿 Regular watering
Oct 1.7" 0" ❄️ Dormant
Nov 1.4" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Gilpin 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 ~806 GDD — county provides 1,451 GDD Excellent fit

Comfrey Planting Timeline — Gilpin County, CO

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors May 21 May 21 – Jun 4
Harvest July 23 Jul 23 – Oct 1

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June Transplant Outdoors
July Harvest
August Harvest
September Harvest
October Harvest
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 5b

📆 Growing Season

135 days in Gilpin County

Growing Tips for Comfrey in Gilpin County

Direct sow Comfrey outdoors after May 14 in Gilpin County when soil has warmed and frost danger has passed.

Gilpin County receives only 19" 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 Gilpin County, CO?

Gilpin County is in Zone 5b with an average last frost of May 14. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.

What planting zone is Gilpin County, CO?

Gilpin County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 14 and first fall frost is September 26.

When should I plant Comfrey in Gilpin County, CO?

In Gilpin County, CO, plant Comfrey after the last frost (around May 14) and before the first frost (around September 26). Best results when soil holds above 50°F.

What growing zone is Gilpin County, CO for Comfrey?

Gilpin County sits in USDA Zone 5b. Comfrey grows reliably in zones 3a through 9b, so it's a good fit here.

Can Comfrey grow in Gilpin County's climate?

Yes — Comfrey grows well in Gilpin County's temperate climate. Gilpin County averages a 135-day frost-free season, with last frost around May 14 and first frost around September 26.

🌱

Your Gilpin County Garden Planner — Free

A 22-page printable planner built for Gilpin County (Zone 5b). 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 Gilpin County, CO. Local conditions may vary. Last updated: July 2026.

Sources & credits

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