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When to plant Mint in Delaware County County,

In Delaware County County, Mint is a single-season spring crop — there's no second fall window. Plant May 9–May 23 for an 90-day harvest, finishing well before the October 7 first frost.

When to Plant Mint in Delaware County, IA

Mint

Mint is a vigorous perennial herb with refreshing, aromatic leaves used in teas, cocktails, and cooking. It spreads aggressively by underground runners.

Delaware County, Iowa is in USDA Zone 5a. The average last spring frost is May 2 and the first fall frost is October 7, giving you a growing season of approximately 158 days.

At an elevation of 974 feet, Delaware County receives approximately 31.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Mint to ensure they mature before fall.

Delaware County, IA (Zone 5a) Moderate season
158 days
Last Spring Frost May 2
158 growing days
First Fall Frost October 7

Delaware County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.8

Drainage

Well Drained

Monthly Watering Guide for Mint

Mint needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Mint Needs Rainfall You Supplement Action
Jan 1.2" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 3.4" 0" ❄️ Dormant
May 4.3" 3.2" 1.1" 💧 Light watering
Jun 4.3" 4.2" 0.1" 💧 Light watering
Jul 4.3" 3.9" 0.4" 💧 Light watering
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 2.6" 1.7" 💧 Light watering
Oct 4.3" 2.1" 2.2" 🚿 Regular watering
Nov 1.8" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

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

Mint Planting Timeline — Delaware County, IA

Mint Planting Calendar

Activity When Date Range
Transplant Outdoors May 9 May 9 – May 23
Harvest July 11 Jul 11 – Sep 19

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

High — keep soil consistently moist

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5a

📆 Growing Season

158 days in Delaware County

Growing Tips for Delaware County

Always grow mint in containers or with underground barriers to control spreading. Harvest regularly to keep plants compact. Cut plants back in late summer for a fresh fall flush.

Companion Planting

Good Companions

Avoid Planting Near

  • Parsley

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mint in Delaware County, IA?

Delaware County is in Zone 5a with an average last frost of May 2. Plan your Mint planting based on this frost date — see the calendar above for exact timing.

What planting zone is Delaware County, IA?

Delaware County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is May 2 and first fall frost is October 7.

When should I plant Mint in Delaware County County, ?

In Delaware County County, , plant Mint after the last frost (around May 2) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Delaware County County, for Mint?

Delaware County County sits in USDA Zone 5a. Mint grows reliably in zones 3a through 10b, so it's a good fit here.

Can Mint grow in Delaware County County's climate?

Yes — Mint grows well in Delaware County County's temperate climate. Delaware County County averages a 158-day frost-free season, with last frost around May 2 and first frost around October 7.

🌱

Your Delaware County Garden Planner — Free

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

Sources & credits

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