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When to Plant Catnip in Foster County, ND

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.

Foster County, North Dakota is in USDA Zone 3b. The average last spring frost is May 10 and the first fall frost is September 30, giving you a growing season of approximately 143 days.

At an elevation of 895 feet, Foster County receives approximately 27.7 inches of rainfall annually with predominantly loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Catnip to ensure they mature before fall.

Foster County, ND (Zone 3b) Short season
143 days
Last Spring Frost May 10
143 growing days
First Fall Frost September 30

Foster County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (13 days to spare)
Transplant: May 8 🍅 Harvest: Jul 10 – Sep 11
Recommended (50%) ✓ Fits season (10 days to spare)
Transplant: May 17 🍅 Harvest: Jul 19 – Sep 20
Safe Start (90%) ✓ Fits season (15 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 Foster County

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

Soil pH

Your soil pH (6.5โ€“7.5) is within Catnip's preferred range (6.0โ€“7.5).

Soil Texture

The loam soil in Foster County is excellent for Catnip โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.0%) โ€” 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 143-day season

Sow every 6.9 weeks. Last sowing by Jul 12 to harvest before frost.

Plant Water Budget

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

Water stress score is 6/10 โ€” 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 โ€” 0.7" 0" โ„๏ธ Dormant
Feb โ€” 1" 0" โ„๏ธ Dormant
Mar โ€” 1.6" 0" โ„๏ธ Dormant
Apr โ€” 3.1" 0" โ„๏ธ Dormant
May 2.2" 4.6" 0" โœ… Rainfall sufficient
Jun 2.2" 4.2" 0" โœ… Rainfall sufficient
Jul 2.2" 3.8" 0" โœ… Rainfall sufficient
Aug 2.2" 3.1" 0" โœ… Rainfall sufficient
Sep 2.2" 2.4" 0" โœ… Rainfall sufficient
Oct โ€” 1.7" 0" โ„๏ธ Dormant
Nov โ€” 0.8" 0" โ„๏ธ Dormant
Dec โ€” 0.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Foster County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~752 GDD — county provides 1,537 GDD Excellent fit

Catnip Planting Timeline โ€” Foster County, ND

Catnip Planting Calendar

Activity When Date Range
Transplant Outdoors May 17 May 17 โ€“ May 31
Harvest July 19 Jul 19 โ€“ Sep 20

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“80 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 3b

๐Ÿ“† Growing Season

143 days in Foster County

Growing Tips for Catnip in Foster County

Direct sow Catnip outdoors after May 10 in Foster 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 Foster County, ND?

Foster County is in Zone 3b with an average last frost of May 10. Plan your Catnip planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Foster County, ND?

Foster County, North Dakota is in USDA Hardiness Zone 3b. The average last spring frost is May 10 and first fall frost is September 30.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Foster County gardeners in Zone 3b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Foster County, ND. Local conditions may vary. Last updated: April 2026.