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When to Plant Catnip in Weld County, CO

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.

Weld County, Colorado is in USDA Zone 5a. The average last spring frost is May 2 and the first fall frost is October 7, giving you a growing season of approximately 158 days.

At an elevation of 6,992 feet, Weld County receives approximately 18.8 inches of rainfall annually with predominantly loam soil. Summer highs average 87ยฐF, providing good warmth for Catnip during the growing season. With low rainfall, drip irrigation is essential for growing Catnip successfully. Mulch heavily to conserve soil moisture.

Weld County, CO (Zone 5a) Moderate season
158 days
Last Spring Frost May 2
158 growing days
First Fall Frost October 7

Weld County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (25 days to spare)
Transplant: May 4 🍅 Harvest: Jul 6 – Sep 7
Recommended (50%) ✓ Fits season (25 days to spare)
Transplant: May 9 🍅 Harvest: Jul 11 – Sep 12
Safe Start (90%) ✓ Fits season (20 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 Weld County

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

Soil pH

Your soil pH (6.6โ€“8.1) overlaps with Catnip's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Catnip.

How to Plant Catnip

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

Succession Planting Catnip

3
successive plantings in your 158-day season

Sow every 6.9 weeks. Last sowing by Jul 19 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
Watering frequency Only during dry spells
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 8/10 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€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1" 0" โ„๏ธ Dormant
Mar โ€” 1.5" 0" โ„๏ธ Dormant
Apr โ€” 2.1" 0" โ„๏ธ Dormant
May 2.2" 2.3" 0" โœ… Rainfall sufficient
Jun 2.2" 1.4" 0.8" ๐Ÿ’ง Light watering
Jul 2.2" 1.7" 0.5" ๐Ÿ’ง Light watering
Aug 2.2" 1.8" 0.4" ๐Ÿ’ง Light watering
Sep 2.2" 1.7" 0.5" ๐Ÿ’ง Light watering
Oct 2.2" 1.7" 0.5" ๐Ÿ’ง Light watering
Nov โ€” 1.2" 0" โ„๏ธ Dormant
Dec โ€” 1.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Weld 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 ~1,068 GDD — county provides 2,409 GDD Excellent fit

Catnip Planting Timeline โ€” Weld County, CO

Catnip Planting Calendar

Activity When Date Range
Transplant Outdoors May 9 May 9 โ€“ May 23
Harvest July 11 Jul 11 โ€“ Sep 12

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 Only during dry spells

๐Ÿ“… Days to Maturity

60โ€“80 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

158 days in Weld County

Growing Tips for Catnip in Weld County

Direct sow Catnip outdoors after May 02 in Weld County when soil has warmed and frost danger has passed.

Weld County receives only 19" of rain annually. Catnip needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

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 Weld County, CO?

Weld County is in Zone 5a with an average last frost of May 2. Plan your Catnip planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Weld County, CO?

Weld County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is May 2 and first fall frost is October 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Weld County gardeners in Zone 5a 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 Weld County, CO. Local conditions may vary. Last updated: April 2026.