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When to plant Comfrey in Sioux County, IA

Sioux County's 155-day season only supports one Comfrey planting per year. Sow between May 8 and May 22 for the best chance at full maturity before October 3.

When to Plant Comfrey in Sioux County, IA

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

Sioux County, Iowa is in USDA Zone 5a. The average last spring frost is May 1 and the first fall frost is October 3, giving you a growing season of approximately 155 days.

At an elevation of 1,212 feet, Sioux County receives approximately 39.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Comfrey to ensure they mature before fall.

Sioux County, IA (Zone 5a) Moderate season
155 days
Last Spring Frost May 1
155 growing days
First Fall Frost October 3

Sioux County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-7

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 1.8" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 3" 0" ❄️ Dormant
Apr 4" 0" ❄️ Dormant
May 4.3" 4.8" 0" ✅ Rainfall sufficient
Jun 4.3" 4.4" 0" ✅ Rainfall sufficient
Jul 4.3" 4" 0.3" 💧 Light watering
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 3.8" 0.5" 💧 Light watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

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

Comfrey Planting Timeline — Sioux County, IA

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors May 8 May 8 – May 22
Harvest July 10 Jul 10 – Sep 18

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

Month-by-Month Timeline

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

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 5a

📆 Growing Season

155 days in Sioux County

Growing Tips for Sioux County

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 Sioux County, IA?

Sioux County is in Zone 5a with an average last frost of May 1. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sioux County, IA?

Sioux County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is May 1 and first fall frost is October 3.

When should I plant Comfrey in Sioux County, IA?

In Sioux County, IA, plant Comfrey after the last frost (around May 1) and before the first frost (around October 3). Best results when soil holds above 50°F.

What growing zone is Sioux County, IA for Comfrey?

Sioux County sits in USDA Zone 5a. Comfrey grows reliably in zones 3a through 9b, so it's a good fit here.

Can Comfrey grow in Sioux County's climate?

Yes — Comfrey grows well in Sioux County's temperate climate. Sioux County averages a 155-day frost-free season, with last frost around May 1 and first frost around October 3.

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Your Sioux County Garden Planner — Free

A 22-page printable planner built for Sioux County (Zone 5a). 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 Sioux County, IA. Local conditions may vary. Last updated: July 2026.

Sources & credits

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