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When to Plant Comfrey in Clark County, NV

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

Clark County, Nevada is in USDA Zone 9a. The average last spring frost is February 28 and the first fall frost is November 23, giving you a growing season of approximately 268 days.

At an elevation of 2,811 feet, Clark County receives approximately 9.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 111ยฐF, so Comfrey may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” 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.

Clark County, NV (Zone 9a) Long season
268 days
Last Spring Frost February 28
268 growing days
First Fall Frost November 23

Clark County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.3-8.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (133 days to spare)
Transplant: Feb 18 🍅 Harvest: Apr 22 – Jul 1
Recommended (50%) ✓ Fits season (128 days to spare)
Transplant: Mar 7 🍅 Harvest: May 9 – Jul 18
Safe Start (90%) ✓ Fits season (114 days to spare)
Transplant: Apr 12 🍅 Harvest: Jun 14 – Aug 23

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 Clark County

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

Soil pH

Your soil pH (7.3โ€“8.4) is more alkaline than Comfrey prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Clark 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

5
successive plantings in your 268-day season

Sow every 6.9 weeks. Last sowing by Aug 25 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 3,318 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” 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 โ€” 0.7" 0" โ„๏ธ Dormant
Feb 4.3" 0.6" 3.7" ๐Ÿšฟ Regular watering
Mar 4.3" 0.6" 3.7" ๐Ÿšฟ Regular watering
Apr 4.3" 0.3" 4" ๐Ÿšฟ Regular watering
May 4.3" 0.2" 4.1" ๐Ÿšฟ Regular watering
Jun 4.3" 0.3" 4" ๐Ÿšฟ Regular watering
Jul 4.3" 1.5" 2.8" ๐Ÿšฟ Regular watering
Aug 4.3" 1.9" 2.4" ๐Ÿšฟ Regular watering
Sep 4.3" 1.2" 3.1" ๐Ÿšฟ Regular watering
Oct 4.3" 0.9" 3.4" ๐Ÿšฟ Regular watering
Nov 4.3" 0.5" 3.8" ๐Ÿšฟ Regular watering
Dec โ€” 0.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Febโ€“Nov in Clark County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~2,494 GDD — county provides 8,944 GDD Excellent fit

Comfrey Planting Timeline โ€” Clark County, NV

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors March 7 Mar 7 โ€“ Mar 21
Harvest May 9 May 9 โ€“ Jul 18

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

268 days in Clark County

Growing Tips for Comfrey in Clark County

Direct sow Comfrey outdoors after February 28 in Clark County when soil has warmed and frost danger has passed.

Sandy soil in Clark County dries quickly โ€” 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 111ยฐF in Clark County, provide afternoon shade for Comfrey and water deeply in the morning.

Clark County receives only 9" of rain annually. Comfrey needs consistent moisture โ€” 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 Clark County, NV?

Clark County is in Zone 9a with an average last frost of February 28. Plan your Comfrey planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Clark County, NV?

Clark County, Nevada is in USDA Hardiness Zone 9a. The average last spring frost is February 28 and first fall frost is November 23.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Clark County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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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 Clark County, NV. Local conditions may vary. Last updated: April 2026.