When to Plant Garlic Chives in Plymouth County, IA
Your April planting checklist for Plymouth County, Iowa
Welcome to April in Zone 5a. These are the moves that will have the biggest impact on your growing season.
To set up a strong May, finish these tasks
- Transplants going out: garlic chives
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.
Plymouth County, Iowa is in USDA Zone 5a. The average last spring frost is April 30 and the first fall frost is October 6, giving you a growing season of approximately 159 days.
At an elevation of 1,392 feet, Plymouth County receives approximately 38 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Garlic Chives to ensure they mature before fall.
Plymouth County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7.2
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 Plymouth County
How your county's soil matches Garlic Chives's growing requirements.
Soil pH
Your soil pH (6.0–7.2) is within Garlic Chives's preferred range (6.0–7.5).
Soil Texture
The silt loam soil in Plymouth County is excellent for Garlic Chives — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.7%) — Garlic Chives will thrive.
How to Plant Garlic Chives
Succession Planting Garlic Chives
Sow every 6.9 weeks. Last sowing by Jul 08 to harvest before frost.
Plant Water Budget
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 | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.6" | 0" | ❄️ Dormant |
| Apr | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.2" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 4.4" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.7" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.8" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Plymouth 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 Planting Timeline — Plymouth County, IA
Garlic Chives Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 7 | May 7 – May 21 |
| Harvest | July 9 | Jul 9 – Sep 17 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
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: ideal
🗺️ USDA Zone
Zone 5a
📆 Growing Season
159 days in Plymouth County
Growing Tips for Garlic Chives in Plymouth County
Direct sow Garlic Chives outdoors after April 30 in Plymouth 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.
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
Check more plant combinations with our Companion Planting Checker →
Garlic Chives in Other Locations
Frequently Asked Questions
When should I plant Garlic Chives in Plymouth County, IA?
Plymouth County is in Zone 5a with an average last frost of April 30. Plan your Garlic Chives planting based on this frost date — see the calendar above for exact timing.
What planting zone is Plymouth County, IA?
Plymouth County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 30 and first fall frost is October 6.
Your Plymouth County Garden Planner — Free
A 24-page printable planner built for Plymouth 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.