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When to Plant Garlic Chives in Johnson County, WY

Johnson County, Wyoming Zone 5a May

May to-do list for Johnson County, Wyoming

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

Avg. last frost May 17
Avg. first frost September 21
Soil temp (4") 30°F
Watering Moderate
Pest pressure Low
Daylight 14.6 hrs
  1. Get garlic chives in the ground

    Frost risk is low now in Johnson County, Wyoming. If you've been covering beds overnight, you can stop.

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Garlic chives are a perennial herb with flat leaves that have a mild garlic flavor. They produce attractive white flower clusters and are used in Asian cooking.

Johnson County, Wyoming is in USDA Zone 5a. The average last spring frost is May 17 and the first fall frost is September 21, giving you a growing season of approximately 127 days.

At an elevation of 8,281 feet, Johnson County receives approximately 23.7 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Garlic Chives to ensure they mature before fall.

Johnson County, WY (Zone 5a) Short season
127 days
Last Spring Frost May 17
127 growing days
First Fall Frost September 21
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Johnson County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 20 🍅 Harvest: Jul 22 – Sep 30
Recommended (50%) ✗ May not fit
Transplant: May 24 🍅 Harvest: Jul 26 – Oct 4
Safe Start (90%) ✗ May not fit
Transplant: Jun 14 🍅 Harvest: Aug 16 – Oct 25

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 Johnson County

How your county's soil matches Garlic Chives's growing requirements.

Soil pH

Your soil pH (6.8–7.8) overlaps with Garlic Chives's range (6.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Johnson County is excellent for Garlic Chives — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Garlic Chives.

Organic Matter

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

How to Plant Garlic Chives

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

Succession Planting Garlic Chives

2
successive plantings in your 127-day season

Sow every 6.9 weeks. Last sowing by Jun 23 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 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Garlic Chives

Garlic Chives 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 Garlic Chives Needs Rainfall You Supplement Action
Jan 1.8" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2.1" 0" ❄️ Dormant
May 2.2" 2.8" 0" ✅ Rainfall sufficient
Jun 2.2" 1.6" 0.6" 💧 Light watering
Jul 2.2" 2.3" 0" ✅ Rainfall sufficient
Aug 2.2" 2.5" 0" ✅ Rainfall sufficient
Sep 2.2" 2.1" 0.1" 💧 Light watering
Oct 2.1" 0" ❄️ Dormant
Nov 1.5" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Johnson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Garlic Chives 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.

Garlic Chives needs ~806 GDD — county provides 1,365 GDD Excellent fit

Garlic Chives Planting Timeline — Johnson County, WY

Garlic Chives Planting Calendar

Activity When Date Range
Transplant Outdoors May 24 May 24 – Jun 7
Harvest July 26 Jul 26 – Oct 4

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June Transplant Outdoors
July Harvest
August Harvest
September Harvest
October Harvest
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

127 days in Johnson County

Growing Tips for Garlic Chives in Johnson County

Direct sow Garlic Chives outdoors after May 17 in Johnson County when soil has warmed and frost danger has passed.

Common pests for Garlic Chives in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

Johnson County receives only 24" of rain annually. Garlic Chives needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start from seed or divisions. Cut flower stalks before seeds set to prevent aggressive self-seeding. Both leaves and flower buds are edible and flavorful.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Garlic Chives in Johnson County, WY?

Johnson County is in Zone 5a with an average last frost of May 17. Plan your Garlic Chives planting based on this frost date — see the calendar above for exact timing.

What planting zone is Johnson County, WY?

Johnson County, Wyoming is in USDA Hardiness Zone 5a. The average last spring frost is May 17 and first fall frost is September 21.

🌱

Your Johnson County Garden Planner — Free

A 24-page printable planner built for Johnson County (Zone 5a). 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 Johnson County, WY. 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.