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When to Plant Comfrey in Humboldt County, NV

Humboldt County, Nevada Zone 6b May

Your May game plan for Humboldt County, Nevada

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

Avg. last frost May 30
Avg. first frost September 15
Soil temp (4") 44°F
Watering Critical
Pest pressure Low
Daylight 14.3 hrs
Before June arrives, get these ready
  • Transplants going out: 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.

Humboldt County, Nevada is in USDA Zone 6b. The average last spring frost is May 30 and the first fall frost is September 15, giving you a growing season of approximately 108 days.

At an elevation of 5,527 feet, Humboldt County receives approximately 8.2 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 94°F, providing good warmth for Comfrey during the growing season. 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.

Humboldt County, NV (Zone 6b) Short season
108 days
Last Spring Frost May 30
108 growing days
First Fall Frost September 15
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Humboldt County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 29 🍅 Harvest: Jul 31 – Oct 9
Recommended (50%) ✗ May not fit
Transplant: Jun 6 🍅 Harvest: Aug 8 – Oct 17
Safe Start (90%) ✗ May not fit
Transplant: Jun 25 🍅 Harvest: Aug 27 – Nov 5

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 Humboldt County

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

Soil pH

Your soil pH (7.2–8.6) is more alkaline than Comfrey prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Humboldt 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 (0.9%). 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

2
successive plantings in your 108-day season

Sow every 6.9 weeks. Last sowing by Jun 17 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.3″/week
You supply
1.2″/week
Watering frequency 2-3 times/week
Season total 1,132 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 0.5" 0" ❄️ Dormant
Mar 0.4" 0" ❄️ Dormant
Apr 0.3" 0" ❄️ Dormant
May 4.3" 0.2" 4.1" 🚿 Regular watering
Jun 4.3" 0.3" 4" 🚿 Regular watering
Jul 4.3" 1.3" 3" 🚿 Regular watering
Aug 4.3" 1.6" 2.7" 🚿 Regular watering
Sep 4.3" 1.1" 3.2" 🚿 Regular watering
Oct 0.8" 0" ❄️ Dormant
Nov 0.4" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Humboldt 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 ~1,538 GDD — county provides 2,214 GDD Excellent fit

Comfrey Planting Timeline — Humboldt County, NV

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors June 6 Jun 6 – Jun 20
Harvest August 8 Aug 8 – Oct 17

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June Transplant Outdoors
July
August Harvest
September Harvest
October Harvest
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 6b

📆 Growing Season

108 days in Humboldt County

Growing Tips for Comfrey in Humboldt County

Direct sow Comfrey outdoors after May 30 in Humboldt County when soil has warmed and frost danger has passed.

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

Humboldt 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 Humboldt County, NV?

Humboldt County is in Zone 6b with an average last frost of May 30. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.

What planting zone is Humboldt County, NV?

Humboldt County, Nevada is in USDA Hardiness Zone 6b. The average last spring frost is May 30 and first fall frost is September 15.

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Your Humboldt County Garden Planner — Free

A 24-page printable planner built for Humboldt County (Zone 6b). 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 Humboldt County, NV. 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.