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When to Plant Catnip in Morton County, ND

Morton County, North Dakota Zone 4a May

May in Morton County, North Dakota — your action list

Welcome to May in Zone 4a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 14
Avg. first frost September 23
Soil temp (4") 55°F
Watering Low
Pest pressure Low
Daylight 14.8 hrs
  1. Get catnip in the ground

    Frost risk is low now in Morton County, North Dakota. If you've been covering beds overnight, you can stop.

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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.

Morton County, North Dakota is in USDA Zone 4a. The average last spring frost is May 14 and the first fall frost is September 23, giving you a growing season of approximately 132 days.

At an elevation of 752 feet, Morton County receives approximately 33 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Catnip to ensure they mature before fall.

Morton County, ND (Zone 4a) Short season
132 days
Last Spring Frost May 14
132 growing days
First Fall Frost September 23
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Morton County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 17 🍅 Harvest: Jul 19 – Sep 20
Recommended (50%) ✗ May not fit
Transplant: May 21 🍅 Harvest: Jul 23 – Sep 24
Safe Start (90%) ✗ May not fit
Transplant: Jun 10 🍅 Harvest: Aug 12 – Oct 14

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 Morton County

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

Soil pH

Your soil pH (6.3–7.6) overlaps with Catnip's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.1%) — Catnip will thrive.

How to Plant Catnip

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

Succession Planting Catnip

2
successive plantings in your 132-day season

Sow every 6.9 weeks. Last sowing by Jul 05 to harvest before frost.

Plant Water Budget

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

Water stress score is 8/10 — 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 2.2" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 3.6" 0" ❄️ Dormant
May 2.2" 4.1" 0" ✅ Rainfall sufficient
Jun 2.2" 2.2" 0" ✅ Rainfall sufficient
Jul 2.2" 2.8" 0" ✅ Rainfall sufficient
Aug 2.2" 4" 0" ✅ Rainfall sufficient
Sep 2.2" 2.9" 0" ✅ Rainfall sufficient
Oct 2.7" 0" ❄️ Dormant
Nov 2.4" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Morton 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 ~700 GDD — county provides 1,320 GDD Excellent fit

Catnip Planting Timeline — Morton County, ND

Catnip Planting Calendar

Activity When Date Range
Transplant Outdoors May 21 May 21 – Jun 4
Harvest July 23 Jul 23 – Sep 24

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June Transplant Outdoors
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 4a

📆 Growing Season

132 days in Morton County

Growing Tips for Catnip in Morton County

Direct sow Catnip outdoors after May 14 in Morton 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 Morton County, ND?

Morton County is in Zone 4a with an average last frost of May 14. Plan your Catnip planting based on this frost date — see the calendar above for exact timing.

What planting zone is Morton County, ND?

Morton County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 14 and first fall frost is September 23.

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Your Morton County Garden Planner — Free

A 24-page printable planner built for Morton County (Zone 4a). 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 Morton County, ND. 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.