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When to Plant Catnip in Lemhi County, ID

Lemhi County, Idaho Zone 5b May

Top priorities for Lemhi County, Idaho gardeners in May

Welcome to May in Zone 5b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost June 9
Avg. first frost September 14
Soil temp (4") 33°F
Watering High
Pest pressure Low
Daylight 14.6 hrs
A few tasks this May that'll pay off in June
  • Transplants going out: catnip

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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.

Lemhi County, Idaho is in USDA Zone 5b. The average last spring frost is June 9 and the first fall frost is September 14, giving you a growing season of approximately 97 days.

At an elevation of 6,743 feet, Lemhi County receives approximately 12.6 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Catnip to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Catnip successfully. Mulch heavily to conserve soil moisture.

Lemhi County, ID (Zone 5b) Very short season
97 days
Last Spring Frost June 9
97 growing days
First Fall Frost September 14

Lemhi County Soil Profile

Soil Type

Loam

Soil pH

6.2-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 21 🍅 Harvest: Jul 23 – Sep 24
Recommended (50%) ✗ May not fit
Transplant: Jun 16 🍅 Harvest: Aug 18 – Oct 20
Safe Start (90%) ✗ May not fit
Transplant: Jul 2 🍅 Harvest: Sep 3 – Nov 5

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 Lemhi County

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

Soil pH

Your soil pH (6.2–8.2) overlaps with Catnip's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Catnip.

How to Plant Catnip

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

Plant Water Budget

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

Water stress score is 6/10 — 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 0.8" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1" 0" ❄️ Dormant
Apr 1.3" 0" ❄️ Dormant
May 1.4" 0" ❄️ Dormant
Jun 2.2" 0.8" 1.4" 🚿 Regular watering
Jul 2.2" 1.3" 0.9" 💧 Light watering
Aug 2.2" 1.3" 0.9" 💧 Light watering
Sep 2.2" 1.2" 1" 💧 Light watering
Oct 1" 0" ❄️ Dormant
Nov 1" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Lemhi 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 ~910 GDD — county provides 1,261 GDD Excellent fit

Catnip Planting Timeline — Lemhi County, ID

Catnip Planting Calendar

Activity When Date Range
Transplant Outdoors June 16 Jun 16 – Jun 30
Harvest August 18 Aug 18 – Oct 20

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June Transplant Outdoors
July
August Harvest
September Harvest
October Harvest
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 5b

📆 Growing Season

97 days in Lemhi County

Growing Tips for Catnip in Lemhi County

Direct sow Catnip outdoors after June 09 in Lemhi County when soil has warmed and frost danger has passed.

Lemhi County receives only 13" of rain annually. Catnip needs consistent moisture — 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 Lemhi County, ID?

Lemhi County is in Zone 5b with an average last frost of June 9. Plan your Catnip planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lemhi County, ID?

Lemhi County, Idaho is in USDA Hardiness Zone 5b. The average last spring frost is June 9 and first fall frost is September 14.

🌱

Your Lemhi County Garden Planner — Free

A 24-page printable planner built for Lemhi County (Zone 5b). 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 Lemhi County, ID. 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.