When to Plant Catnip in Cowlitz County, WA
Your May game plan for Cowlitz County, Washington
Welcome to May in Zone 8b. These are the moves that will have the biggest impact on your growing season.
Before June arrives, get these ready
- First harvests: catnip
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.
Cowlitz County, Washington is in USDA Zone 8b. The average last spring frost is April 15 and the first fall frost is October 29, giving you a growing season of approximately 197 days.
At an elevation of 268 feet, Cowlitz County receives approximately 47.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Catnip during the growing season.
Cowlitz County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.5
Drainage
Well Drained
Plant Planting Risk Windows
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 Cowlitz County
How your county's soil matches Catnip's growing requirements.
Soil pH
Your soil pH (5.7–6.5) overlaps with Catnip's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Cowlitz County is excellent for Catnip — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.3%) — Catnip will thrive.
How to Plant Catnip
Succession Planting Catnip
Sow every 6.9 weeks. Last sowing by Aug 10 to harvest before frost.
Plant Water Budget
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 | — | 7.2" | 0" | ❄️ Dormant |
| Feb | — | 4.6" | 0" | ❄️ Dormant |
| Mar | — | 5.1" | 0" | ❄️ Dormant |
| Apr | 2.2" | 3.6" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 2" | 0.2" | 💧 Light watering |
| Jul | 2.2" | 0.8" | 1.4" | 🚿 Regular watering |
| Aug | 2.2" | 0.9" | 1.3" | 🚿 Regular watering |
| Sep | 2.2" | 1.6" | 0.6" | 💧 Light watering |
| Oct | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Nov | — | 7.6" | 0" | ❄️ Dormant |
| Dec | — | 7.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Cowlitz 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 Planting Timeline — Cowlitz County, WA
Catnip Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 22 | Apr 22 – May 6 |
| Harvest | June 24 | Jun 24 – Aug 26 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors |
| May | Transplant Outdoors |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
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 8b
📆 Growing Season
197 days in Cowlitz County
Growing Tips for Catnip in Cowlitz County
Direct sow Catnip outdoors after April 15 in Cowlitz 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 →
Catnip in Other Locations
Frequently Asked Questions
When should I plant Catnip in Cowlitz County, WA?
Cowlitz County is in Zone 8b with an average last frost of April 15. Plan your Catnip planting based on this frost date — see the calendar above for exact timing.
What planting zone is Cowlitz County, WA?
Cowlitz County, Washington is in USDA Hardiness Zone 8b. The average last spring frost is April 15 and first fall frost is October 29.
Your Cowlitz County Garden Planner — Free
A 24-page printable planner built for Cowlitz County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.