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When to Plant Catnip in Sonoma County, CA

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.

Sonoma County, California is in USDA Zone 9a. The average last spring frost is February 26 and the first fall frost is November 26, giving you a growing season of approximately 273 days.

At an elevation of 91 feet, Sonoma County receives approximately 31.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 90ยฐF, providing good warmth for Catnip during the growing season. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Catnip will need more frequent watering and organic matter to retain nutrients.

Sonoma County, CA (Zone 9a) Year-round
273 days
Last Spring Frost February 26
273 growing days
First Fall Frost November 26

Sonoma County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.9-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (152 days to spare)
Transplant: Feb 17 🍅 Harvest: Apr 21 – Jun 23
Recommended (50%) ✓ Fits season (140 days to spare)
Transplant: Mar 5 🍅 Harvest: May 7 – Jul 9
Safe Start (90%) ✓ Fits season (126 days to spare)
Transplant: Apr 9 🍅 Harvest: Jun 11 – Aug 13

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 Sonoma County

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

Soil pH

Your soil pH (5.9โ€“7.0) overlaps with Catnip's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

Sandy soil in Sonoma County warms quickly in spring but drains fast. Catnip will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Catnip.

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Catnip.

How to Plant Catnip

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

Succession Planting Catnip

5
successive plantings in your 273-day season

Sow every 6.9 weeks. Last sowing by Sep 07 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 507 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€” 6.2" 0" โ„๏ธ Dormant
Feb 2.2" 6.8" 0" โœ… Rainfall sufficient
Mar 2.2" 5.2" 0" โœ… Rainfall sufficient
Apr 2.2" 2.3" 0" โœ… Rainfall sufficient
May 2.2" 0.8" 1.4" ๐Ÿšฟ Regular watering
Jun 2.2" 0.1" 2.1" ๐Ÿšฟ Regular watering
Jul 2.2" 0" 2.2" ๐Ÿšฟ Regular watering
Aug 2.2" 0" 2.2" ๐Ÿšฟ Regular watering
Sep 2.2" 0.4" 1.8" ๐Ÿšฟ Regular watering
Oct 2.2" 1.3" 0.9" ๐Ÿ’ง Light watering
Nov 2.2" 2.7" 0" โœ… Rainfall sufficient
Dec โ€” 5.2" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Febโ€“Nov in Sonoma 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 ~1,225 GDD — county provides 4,795 GDD Excellent fit

Catnip Planting Timeline โ€” Sonoma County, CA

Catnip Planting Calendar

Activity When Date Range
Transplant Outdoors March 5 Mar 5 โ€“ Mar 19
Harvest May 7 May 7 โ€“ Jul 9

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Transplant Outdoors
April โ€”
May Harvest
June Harvest
July Harvest
August โ€”
September โ€”
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 9a

๐Ÿ“† Growing Season

273 days in Sonoma County

Growing Tips for Catnip in Sonoma County

Direct sow Catnip outdoors after February 26 in Sonoma County when soil has warmed and frost danger has passed.

Sandy soil in Sonoma County dries quickly โ€” mulch Catnip with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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 Sonoma County, CA?

Sonoma County is in Zone 9a with an average last frost of February 26. Plan your Catnip planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Sonoma County, CA?

Sonoma County, California is in USDA Hardiness Zone 9a. The average last spring frost is February 26 and first fall frost is November 26.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Sonoma County gardeners in Zone 9a 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 Sonoma County, CA. Local conditions may vary. Last updated: April 2026.