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When to plant Comfrey in Isleton,

Plant Comfrey in Isleton during the brief February 19–March 5 window. With 293 frost-free days, fall plantings can't mature before December 1.

When to Plant Comfrey in Isleton, CA

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

Isleton, California is in USDA Zone 9b. The average last spring frost is February 12 and the first fall frost is December 1, giving you a growing season of approximately 292 days.

At an elevation of 263 feet, Sacramento County receives approximately 33.2 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Comfrey during the growing season.

Isleton, CA (Zone 9b) Year-round
292 days
Last Spring Frost February 12
292 growing days
First Fall Frost December 1
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Isleton Soil Profile

Soil Type

Loam

Soil pH

6.4-7.1

Drainage

Well Drained

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 6.1" 0" ❄️ Dormant
Feb 4.3" 7.5" 0" ✅ Rainfall sufficient
Mar 4.3" 5.7" 0" ✅ Rainfall sufficient
Apr 4.3" 2.5" 1.8" 💧 Light watering
May 4.3" 0.8" 3.5" 🚿 Regular watering
Jun 4.3" 0.2" 4.1" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.3" 4" 🚿 Regular watering
Oct 4.3" 1.4" 2.9" 🚿 Regular watering
Nov 4.3" 2.7" 1.6" 💧 Light watering
Dec 4.3" 5.9" 0" ✅ Rainfall sufficient

Water needs are for active growing months only (Feb–Dec in Sacramento County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Comfrey Planting Timeline — Isleton, CA

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors February 19 Feb 19 – Mar 5
Harvest April 23 Apr 23 – Jul 2

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

Month-by-Month Timeline

MonthActivities
January
February Transplant Outdoors
March Transplant Outdoors
April Harvest
May Harvest
June Harvest
July Harvest
August
September
October
November
December
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 9b

📆 Growing Season

292 days in Sacramento County

Growing Tips for Isleton

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 →

When should I plant Comfrey in Isleton, ?

In Isleton, , plant Comfrey after the last frost (around February 12) and before the first frost (around December 1). Best results when soil holds above 50°F.

What growing zone is Isleton, for Comfrey?

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

Can Comfrey grow in Isleton's climate?

Yes — Comfrey grows well in Isleton's temperate climate. Isleton averages a 293-day frost-free season, with last frost around February 12 and first frost around December 1.

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Your Sacramento County Garden Planner — Free

A 22-page printable planner built for Sacramento 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 Sacramento County, CA. Local conditions may vary. Last updated: June 2026.