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When to Plant Endive in Grant County, OR

Grant County, Oregon Zone 6b May

May in Grant County, Oregon — your action list

A quick May briefing for Grant County, Oregon gardeners — what's urgent, what's next, and what can wait.

Avg. last frost June 6
Avg. first frost September 10
Soil temp (4") 51°F
Watering High
Pest pressure Low
Daylight 14.6 hrs
  1. Direct-sow endive

    Mark the row. Birds and stray feet both have opinions about unmarked beds.

Get ahead of June
  • Transplants going out: endive

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Endive is a leafy green with a slightly bitter flavor, available in curly (frisee) and broad-leaved (escarole) types. It adds texture and complexity to salads.

Grant County, Oregon is in USDA Zone 6b. The average last spring frost is June 6 and the first fall frost is September 10, giving you a growing season of approximately 96 days.

At an elevation of 2,838 feet, Grant County receives approximately 22.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Endive to ensure they mature before fall.

Grant County, OR (Zone 6b) Very short season
96 days
Last Spring Frost June 6
96 growing days
First Fall Frost September 10
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Grant County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (4 days to spare)
Start indoors: Apr 15 Transplant: May 20 🍅 Harvest: Jul 8 – Aug 12
Recommended (50%) ✓ Fits season (12 days to spare)
Start indoors: May 2 Transplant: Jun 6 🍅 Harvest: Jul 25 – Aug 29
Safe Start (90%) ✓ Fits season (16 days to spare)
Start indoors: May 22 Transplant: Jun 26 🍅 Harvest: Aug 14 – Sep 18

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 Grant County

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

Soil pH

Your soil pH (5.4–6.4) overlaps with Endive's range (5.5–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Grant County is excellent for Endive — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Endive.

Organic Matter

Organic matter is excellent (4.8%) — Endive will thrive.

How to Plant Endive

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Endive

2
successive plantings in your 96-day season

Sow every 5.1 weeks. Last sowing by Jul 07 to harvest before frost.

For a dedicated fall crop, sow by Jul 02.

Plant Water Budget

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

Monthly Watering Guide for Endive

Endive needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Endive Needs Rainfall You Supplement Action
Jan 3.2" 0" ❄️ Dormant
Feb 2.9" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 1.3" 0" ❄️ Dormant
Jun 3" 0.8" 2.2" 🚿 Regular watering
Jul 3" 0.4" 2.6" 🚿 Regular watering
Aug 3" 0.4" 2.6" 🚿 Regular watering
Sep 3" 0.9" 2.1" 🚿 Regular watering
Oct 1.8" 0" ❄️ Dormant
Nov 3.1" 0" ❄️ Dormant
Dec 3.9" 0" ❄️ Dormant

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

Endive 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.

Endive needs ~674 GDD — county provides 1,176 GDD Excellent fit

Endive Planting Timeline — Grant County, OR

Endive Planting Calendar

Activity When Date Range
Start Indoors May 2 May 2 – May 16
Transplant Outdoors June 6 Jun 6 – Jun 20
Direct Sow May 23 May 23 – Jun 13
Harvest July 25 Jul 25 – Aug 29
Fall Sowing July 2 Jul 2 – Jul 16

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Start Indoors Direct Sow
June Transplant Outdoors Direct Sow
July Fall Sowing Harvest
August Harvest
September
October
November
December
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

45–65 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

96 days in Grant County

Growing Tips for Endive in Grant County

Direct sow Endive outdoors after June 06 in Grant County when soil has warmed and frost danger has passed.

Common pests for Endive in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Sow seeds directly in spring or fall. Blanch heads by tying outer leaves together 2-3 weeks before harvest to reduce bitterness. Keep soil evenly moist.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Endive in Grant County, OR?

Grant County is in Zone 6b with an average last frost of June 6. Plan your Endive planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grant County, OR?

Grant County, Oregon is in USDA Hardiness Zone 6b. The average last spring frost is June 6 and first fall frost is September 10.

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Your Grant County Garden Planner — Free

A 24-page printable planner built for Grant County (Zone 6b). 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 Grant 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.