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When to plant Catnip in McHenry County, IL

Plant Catnip in McHenry County during the brief April 25–May 9 window. With 185 frost-free days, fall plantings can't mature before October 20.

When to Plant Catnip in McHenry County, IL

Catnip is a hardy perennial herb in the mint family known for its effect on cats. It also makes a calming tea and is a useful companion plant that repels some pests.

McHenry County, Illinois is in USDA Zone 5b. The average last spring frost is April 18 and the first fall frost is October 20, giving you a growing season of approximately 185 days.

At an elevation of 640 feet, McHenry County receives approximately 39.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Catnip to ensure they mature before fall.

McHenry County, IL (Zone 5b) Moderate season
185 days
Last Spring Frost April 18
185 growing days
First Fall Frost October 20

McHenry County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.7

Drainage

Well Drained

Monthly Watering Guide for Catnip

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

Month Catnip Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 4.3" 4.2" 0.1" 💧 Light watering
May 4.3" 4.2" 0.1" 💧 Light watering
Jun 4.3" 4.8" 0" ✅ Rainfall sufficient
Jul 4.3" 4.1" 0.2" 💧 Light watering
Aug 4.3" 4.5" 0" ✅ Rainfall sufficient
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

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

Catnip Planting Timeline — McHenry County, IL

Catnip Planting Calendar

Activity When Date Range
Transplant Outdoors April 25 Apr 25 – May 9
Harvest June 27 Jun 27 – Aug 29

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

185 days in McHenry County

Growing Tips for McHenry County

Direct sow or start indoors. Catnip is very easy to grow and can become invasive. Harvest leaves before flowering for tea. Protect young plants from cats.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Catnip in McHenry County, IL?

McHenry County is in Zone 5b with an average last frost of April 18. Plan your Catnip planting based on this frost date — see the calendar above for exact timing.

What planting zone is McHenry County, IL?

McHenry County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 18 and first fall frost is October 20.

When should I plant Catnip in McHenry County, IL?

In McHenry County, IL, plant Catnip after the last frost (around April 18) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is McHenry County, IL for Catnip?

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

Can Catnip grow in McHenry County's climate?

Yes — Catnip grows well in McHenry County's temperate climate. McHenry County averages a 185-day frost-free season, with last frost around April 18 and first frost around October 20.

🌱

Your McHenry County Garden Planner — Free

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

Sources & credits

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