Blog

When to Plant Comfrey in Summit County, UT

Summit County, Utah Zone 5b May

Summit County, Utah gardeners: here's your May plan

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Summit County, Utah.

Avg. last frost June 10
Avg. first frost September 12
Soil temp (4") 33°F
Watering Moderate
Pest pressure Low
Daylight 14.3 hrs
A few tasks this May that'll pay off in June
  • Transplants going out: 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.

Summit County, Utah is in USDA Zone 5b. The average last spring frost is June 10 and the first fall frost is September 12, giving you a growing season of approximately 94 days.

At an elevation of 8,145 feet, Summit County receives approximately 24.8 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Comfrey during the growing season.

Summit County, UT (Zone 5b) Very short season
94 days
Last Spring Frost June 10
94 growing days
First Fall Frost September 12

Summit County Soil Profile

Soil Type

Loam

Soil pH

6.4-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Jun 6 🍅 Harvest: Aug 8 – Oct 17
Recommended (50%) ✗ May not fit
Transplant: Jun 17 🍅 Harvest: Aug 19 – Oct 28
Safe Start (90%) ✗ May not fit
Transplant: Jun 28 🍅 Harvest: Aug 30 – Nov 8

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 Summit County

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

Soil pH

Your soil pH (6.4–8.3) is more alkaline than Comfrey prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Summit 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

Plant Water Budget

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

Water stress score is 8/10 — 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 1.6" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 2.9" 0" ❄️ Dormant
May 2.9" 0" ❄️ Dormant
Jun 4.3" 1.8" 2.5" 🚿 Regular watering
Jul 4.3" 1.9" 2.4" 🚿 Regular watering
Aug 4.3" 2.5" 1.8" 💧 Light watering
Sep 4.3" 2" 2.3" 🚿 Regular watering
Oct 2.1" 0" ❄️ Dormant
Nov 2" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Summit 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 ~1,088 GDD — county provides 1,363 GDD Good fit

Comfrey Planting Timeline — Summit County, UT

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors June 17 Jun 17 – Jul 1
Harvest August 19 Aug 19 – Oct 28

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 5b

📆 Growing Season

94 days in Summit County

Growing Tips for Comfrey in Summit County

Direct sow Comfrey outdoors after June 10 in Summit County when soil has warmed and frost danger has passed.

Your 94.0-day growing season in Summit County is tight for Comfrey (60.0-90.0 days to maturity). Start indoors and choose early-maturing varieties.

Summit County receives only 25" 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 Summit County, UT?

Summit County is in Zone 5b with an average last frost of June 10. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.

What planting zone is Summit County, UT?

Summit County, Utah is in USDA Hardiness Zone 5b. The average last spring frost is June 10 and first fall frost is September 12.

🌱

Your Summit County Garden Planner — Free

A 24-page printable planner built for Summit 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.

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 Summit County, UT. 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.