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When to plant Catnip in Cass County, MI

Plant Catnip in Cass County, between May 6 and May 20 — the only viable window. Zone 6a's short season (171 frost-free days) rules out a fall crop.

When to Plant Catnip in Cass County, MI

Cass County, Michigan Zone 6a July

July to-do list for Cass County, Michigan

Here's what deserves your attention in Cass County, Michigan this month. Everything below is tailored to Zone 6a and timed around your local frost dates.

Avg. last frost April 29
Avg. first frost October 17
Soil temp (4") 81°F
Watering Low
Pest pressure High
Daylight 14.8 hrs
  1. Bring in the catnip

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Coming up in August — start thinking about
  • First harvests: catnip

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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.

Cass County, Michigan is in USDA Zone 6a. The average last spring frost is April 29 and the first fall frost is October 17, giving you a growing season of approximately 171 days.

At an elevation of 1,030 feet, Cass County receives approximately 34.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Catnip during the growing season.

Cass County, MI (Zone 6a) Moderate season
171 days
Last Spring Frost April 29
171 growing days
First Fall Frost October 17

Cass County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Catnip Planting Risk Windows

Early Start (70% safe) ✓ Fits season (35 days to spare)
Transplant: May 3 🍅 Harvest: Jul 5 – Sep 6
Recommended (50%) ✓ Fits season (38 days to spare)
Transplant: May 6 🍅 Harvest: Jul 8 – Sep 9
Safe Start (90%) ✓ Fits season (30 days to spare)
Transplant: May 26 🍅 Harvest: Jul 28 – Sep 29

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 Cass County

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

Soil pH

Your soil pH (6.2–7.2) is within Catnip's preferred range (6.0–7.5).

Soil Texture

The silt loam soil in Cass County is excellent for Catnip — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.9%) — Catnip will thrive.

How to Plant Catnip

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Catnip

3
successive plantings in your 171-day season

Sow every 6.9 weeks. Last sowing by Jul 29 to harvest before frost.

Catnip Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Catnip

Catnip needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Catnip Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 2.2" 3.5" 0" ✅ Rainfall sufficient
May 2.2" 3.9" 0" ✅ Rainfall sufficient
Jun 2.2" 4.5" 0" ✅ Rainfall sufficient
Jul 2.2" 3.8" 0" ✅ Rainfall sufficient
Aug 2.2" 3.5" 0" ✅ Rainfall sufficient
Sep 2.2" 3.2" 0" ✅ Rainfall sufficient
Oct 2.2" 2.2" 0" ✅ Rainfall sufficient
Nov 2.1" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

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

Catnip 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" — every day above 50°F 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.

Catnip needs ~1,015 GDD — county provides 2,479 GDD Excellent fit

Catnip Planting Timeline — Cass County, MI

Catnip Planting Calendar

Activity When Date Range
Transplant Outdoors May 6 May 6 – May 20
Harvest July 8 Jul 8 – Sep 9

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

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

171 days in Cass County

Growing Tips for Catnip in Cass County

Direct sow Catnip outdoors after April 29 in Cass County when soil has warmed and frost danger has passed.

General growing tips

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 Cass County, MI?

Cass County is in Zone 6a with an average last frost of April 29. Plan your Catnip planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cass County, MI?

Cass County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is April 29 and first fall frost is October 17.

When should I plant Catnip in Cass County, MI?

In Cass County, MI, plant Catnip after the last frost (around April 29) and before the first frost (around October 17). Best results when soil holds above 50°F.

What growing zone is Cass County, MI for Catnip?

Cass County sits in USDA Zone 6a. Catnip grows reliably in zones 3a through 9b, so it's a good fit here.

Can Catnip grow in Cass County's climate?

Yes — Catnip grows well in Cass County's temperate climate. Cass County averages a 171-day frost-free season, with last frost around April 29 and first frost around October 17.

🌱

Your Cass County Garden Planner — Free

A 22-page printable planner built for Cass County (Zone 6a). 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 Cass County, MI. Local conditions may vary. Last updated: July 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.