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When to Plant Garlic Chives in Benton County, OR

Benton County, Oregon Zone 8b May

May in Benton County, Oregon — your action list

We've pulled the most time-sensitive tasks for Benton County, Oregon this May and put them front and centre. Tackle them in order.

Avg. last frost April 14
Avg. first frost October 30
Soil temp (4") 72°F
Watering Moderate
Pest pressure High
Daylight 14.6 hrs
Before June arrives, get these ready
  • First harvests: garlic chives

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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.

Benton County, Oregon is in USDA Zone 8b. The average last spring frost is April 14 and the first fall frost is October 30, giving you a growing season of approximately 199 days.

At an elevation of 97 feet, Benton County receives approximately 53.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Garlic Chives during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Garlic Chives root diseases.

Benton County, OR (Zone 8b) Moderate season
199 days
Last Spring Frost April 14
199 growing days
First Fall Frost October 30

Benton County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (71 days to spare)
Transplant: Apr 3 🍅 Harvest: Jun 5 – Aug 14
Recommended (50%) ✓ Fits season (59 days to spare)
Transplant: Apr 21 🍅 Harvest: Jun 23 – Sep 1
Safe Start (90%) ✓ Fits season (66 days to spare)
Transplant: May 14 🍅 Harvest: Jul 16 – Sep 24

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 Benton County

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

Soil pH

Your soil pH (5.6–6.2) is more acidic than Garlic Chives prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Benton 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

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

Succession Planting Garlic Chives

3
successive plantings in your 199-day season

Sow every 6.9 weeks. Last sowing by Aug 01 to harvest before frost.

Plant Water Budget

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

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 8.1" 0" ❄️ Dormant
Feb 6.1" 0" ❄️ Dormant
Mar 5.8" 0" ❄️ Dormant
Apr 2.2" 3.6" 0" ✅ Rainfall sufficient
May 2.2" 3.3" 0" ✅ Rainfall sufficient
Jun 2.2" 1.9" 0.3" 💧 Light watering
Jul 2.2" 0.9" 1.3" 🚿 Regular watering
Aug 2.2" 0.8" 1.4" 🚿 Regular watering
Sep 2.2" 2.3" 0" ✅ Rainfall sufficient
Oct 2.2" 3.8" 0" ✅ Rainfall sufficient
Nov 8.3" 0" ❄️ Dormant
Dec 8.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Benton 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 ~1,031 GDD — county provides 2,736 GDD Excellent fit

Garlic Chives Planting Timeline — Benton County, OR

Garlic Chives Planting Calendar

Activity When Date Range
Transplant Outdoors April 21 Apr 21 – May 5
Harvest June 23 Jun 23 – Sep 1

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Transplant Outdoors
May Transplant Outdoors
June Harvest
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: too_acidic

🗺️ USDA Zone

Zone 8b

📆 Growing Season

199 days in Benton County

Growing Tips for Garlic Chives in Benton County

Direct sow Garlic Chives outdoors after April 14 in Benton 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

  • Peas
  • Green Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Garlic Chives in Benton County, OR?

Benton County is in Zone 8b with an average last frost of April 14. Plan your Garlic Chives planting based on this frost date — see the calendar above for exact timing.

What planting zone is Benton County, OR?

Benton County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 14 and first fall frost is October 30.

🌱

Your Benton County Garden Planner — Free

A 24-page printable planner built for Benton 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.

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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 Benton County, OR. 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.