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When to Plant Catnip in Tama County, IA

Tama County, Iowa Zone 5a May

Top priorities for Tama County, Iowa gardeners in May

May is a pivotal month for Tama County, Iowa gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 28
Avg. first frost October 8
Soil temp (4") 58°F
Watering Low
Pest pressure Low
Daylight 14.4 hrs
  1. Time to transplant catnip

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

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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.

Tama County, Iowa is in USDA Zone 5a. The average last spring frost is April 28 and the first fall frost is October 8, giving you a growing season of approximately 163 days.

At an elevation of 1,268 feet, Tama County receives approximately 38.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Catnip during the growing season.

Tama County, IA (Zone 5a) Moderate season
163 days
Last Spring Frost April 28
163 growing days
First Fall Frost October 8
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Tama County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (31 days to spare)
Transplant: Apr 29 🍅 Harvest: Jul 1 – Sep 2
Recommended (50%) ✓ Fits season (30 days to spare)
Transplant: May 5 🍅 Harvest: Jul 7 – Sep 8
Safe Start (90%) ✓ Fits season (24 days to spare)
Transplant: May 19 🍅 Harvest: Jul 21 – Sep 22

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 Tama 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 Tama County is excellent for Catnip — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Catnip.

Organic Matter

Organic matter is excellent (5.1%) — 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 163-day season

Sow every 6.9 weeks. Last sowing by Jul 20 to harvest before frost.

Plant Water Budget

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

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.4" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 2.2" 3.2" 0" ✅ Rainfall sufficient
May 2.2" 4.6" 0" ✅ Rainfall sufficient
Jun 2.2" 5.1" 0" ✅ Rainfall sufficient
Jul 2.2" 4.1" 0" ✅ Rainfall sufficient
Aug 2.2" 3.9" 0" ✅ Rainfall sufficient
Sep 2.2" 3.8" 0" ✅ Rainfall sufficient
Oct 2.2" 2.6" 0" ✅ Rainfall sufficient
Nov 3" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Tama 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 ~962 GDD — county provides 2,241 GDD Excellent fit

Catnip Planting Timeline — Tama County, IA

Catnip Planting Calendar

Activity When Date Range
Transplant Outdoors May 5 May 5 – May 19
Harvest July 7 Jul 7 – Sep 8

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
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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

163 days in Tama County

Growing Tips for Catnip in Tama County

Direct sow Catnip outdoors after April 28 in Tama 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 Tama County, IA?

Tama County is in Zone 5a with an average last frost of April 28. Plan your Catnip planting based on this frost date — see the calendar above for exact timing.

What planting zone is Tama County, IA?

Tama County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 28 and first fall frost is October 8.

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Your Tama County Garden Planner — Free

A 24-page printable planner built for Tama 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 Tama County, IA. Local conditions may vary. Last updated: May 2026.

Sources & credits

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