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When to plant Catnip in Greene County, IA

Greene County's short 161-day growing season means one Catnip planting between May 4 and May 18. No fall crop in Zone 5a.

When to Plant Catnip in Greene County, IA

Greene County, Iowa Zone 5a July

Your July game plan for Greene County, Iowa

Your Greene County, Iowa garden is entering a new phase. Here's what's on the schedule for July and why each task matters now.

Avg. last frost April 27
Avg. first frost October 5
Soil temp (4") 74°F
Watering Moderate
Pest pressure High
Daylight 14.8 hrs
  1. Pick catnip

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Before August arrives, get these ready
  • 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.

Greene County, Iowa is in USDA Zone 5a. The average last spring frost is April 27 and the first fall frost is October 5, giving you a growing season of approximately 161 days.

At an elevation of 1,292 feet, Greene County receives approximately 33.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Catnip during the growing season.

Greene County, IA (Zone 5a) Moderate season
161 days
Last Spring Frost April 27
161 growing days
First Fall Frost October 5

Greene County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.9

Drainage

Well Drained

Catnip Planting Risk Windows

Early Start (70% safe) ✓ Fits season (26 days to spare)
Transplant: Apr 29 🍅 Harvest: Jul 1 – Sep 2
Recommended (50%) ✓ Fits season (28 days to spare)
Transplant: May 4 🍅 Harvest: Jul 6 – Sep 7
Safe Start (90%) ✓ Fits season (26 days to spare)
Transplant: May 18 🍅 Harvest: Jul 20 – Sep 21

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 Greene County

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

Soil pH

Your soil pH (5.8–6.9) overlaps with Catnip's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — 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 161-day season

Sow every 6.9 weeks. Last sowing by Jul 17 to harvest before frost.

Catnip Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/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 1.3" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 2.2" 3.1" 0" ✅ Rainfall sufficient
May 2.2" 4" 0" ✅ Rainfall sufficient
Jun 2.2" 4.6" 0" ✅ Rainfall sufficient
Jul 2.2" 3.3" 0" ✅ Rainfall sufficient
Aug 2.2" 3.6" 0" ✅ Rainfall sufficient
Sep 2.2" 2.9" 0" ✅ Rainfall sufficient
Oct 2.2" 2.4" 0" ✅ Rainfall sufficient
Nov 2.1" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Greene 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 2,334 GDD Excellent fit

Catnip Planting Timeline — Greene County, IA

Catnip Planting Calendar

Activity When Date Range
Transplant Outdoors May 4 May 4 – May 18
Harvest July 6 Jul 6 – Sep 7

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: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

161 days in Greene County

Growing Tips for Catnip in Greene County

Direct sow Catnip outdoors after April 27 in Greene 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 Greene County, IA?

Greene County is in Zone 5a with an average last frost of April 27. Plan your Catnip planting based on this frost date — see the calendar above for exact timing.

What planting zone is Greene County, IA?

Greene County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 27 and first fall frost is October 5.

When should I plant Catnip in Greene County, IA?

In Greene County, IA, plant Catnip after the last frost (around April 27) and before the first frost (around October 5). Best results when soil holds above 50°F.

What growing zone is Greene County, IA for Catnip?

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

Can Catnip grow in Greene County's climate?

Yes — Catnip grows well in Greene County's temperate climate. Greene County averages a 161-day frost-free season, with last frost around April 27 and first frost around October 5.

🌱

Your Greene County Garden Planner — Free

A 22-page printable planner built for Greene 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 Greene County, IA. 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.