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When to Plant Comfrey in Mohave County, AZ

Mohave County, Arizona Zone 9b May

What to do in May

Your Mohave County, Arizona garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost April 5
Avg. first frost November 8
Soil temp (4") 64°F
Watering Critical
Pest pressure High
Daylight 13.9 hrs
Looking ahead to June
  • 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.

Mohave County, Arizona is in USDA Zone 9b. The average last spring frost is April 5 and the first fall frost is November 8, giving you a growing season of approximately 217 days.

At an elevation of 3,748 feet, Mohave County receives approximately 8.2 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Comfrey may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Comfrey will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Comfrey successfully. Mulch heavily to conserve soil moisture.

Mohave County, AZ (Zone 9b) Long season
217 days
Last Spring Frost April 5
217 growing days
First Fall Frost November 8
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Mohave County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (86 days to spare)
Transplant: Mar 30 🍅 Harvest: Jun 1 – Aug 10
Recommended (50%) ✓ Fits season (77 days to spare)
Transplant: Apr 12 🍅 Harvest: Jun 14 – Aug 23
Safe Start (90%) ✓ Fits season (78 days to spare)
Transplant: Apr 24 🍅 Harvest: Jun 26 – Sep 4

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 Mohave County

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

Soil pH

Your soil pH (7.2–8.4) is more alkaline than Comfrey prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Mohave County warms quickly in spring but drains fast. Comfrey will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Comfrey.

Organic Matter

Organic matter is low (0.8%). Add 2-3 inches of compost before planting Comfrey.

How to Plant Comfrey

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

Succession Planting Comfrey

4
successive plantings in your 217-day season

Sow every 6.9 weeks. Last sowing by Aug 10 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.2″/week
You supply
1.4″/week
Watering frequency 2-3 times/week
Season total 2,645 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 0.6" 0" ❄️ Dormant
Feb 0.4" 0" ❄️ Dormant
Mar 0.4" 0" ❄️ Dormant
Apr 4.3" 0.3" 4" 🚿 Regular watering
May 4.3" 0.2" 4.1" 🚿 Regular watering
Jun 4.3" 0.3" 4" 🚿 Regular watering
Jul 4.3" 1.5" 2.8" 🚿 Regular watering
Aug 4.3" 1.6" 2.7" 🚿 Regular watering
Sep 4.3" 1" 3.3" 🚿 Regular watering
Oct 4.3" 0.8" 3.5" 🚿 Regular watering
Nov 4.3" 0.4" 3.9" 🚿 Regular watering
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Mohave 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 ~1,650 GDD — county provides 4,774 GDD Excellent fit

Comfrey Planting Timeline — Mohave County, AZ

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors April 12 Apr 12 – Apr 26
Harvest June 14 Jun 14 – Aug 23

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
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9b

📆 Growing Season

217 days in Mohave County

Growing Tips for Comfrey in Mohave County

Direct sow Comfrey outdoors after April 05 in Mohave County when soil has warmed and frost danger has passed.

Sandy soil in Mohave County dries quickly — mulch Comfrey with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 96°F in Mohave County, provide afternoon shade for Comfrey and water deeply in the morning.

Mohave County receives only 8" 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 Mohave County, AZ?

Mohave County is in Zone 9b with an average last frost of April 5. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mohave County, AZ?

Mohave County, Arizona is in USDA Hardiness Zone 9b. The average last spring frost is April 5 and first fall frost is November 8.

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Your Mohave County Garden Planner — Free

A 24-page printable planner built for Mohave County (Zone 9b). 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 Mohave County, AZ. 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.