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When to plant Endive in Routt County, CO

Routt County's spring Endive window runs May 29 through June 19. time plantings around the expected last-frost window for best survival. A second sowing from June 30 to July 14 extends the harvest into fall.

When to Plant Endive in Routt County, CO

Routt County, Colorado Zone 5a June

This month in Routt County, Colorado

Each item below is timed to Routt County, Colorado's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost June 12
Avg. first frost September 8
Soil temp (4") 48°F
Watering High
Pest pressure High
Daylight 14.9 hrs
  1. Plant out endive

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

  2. Direct-sow endive for cool weather

    A row cover ready in the garage extends your harvest by weeks once the nights turn cold.

Before July arrives, get these ready
  • Starting indoors: endive
  • First harvests: 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.

Routt County, Colorado is in USDA Zone 5a. The average last spring frost is June 12 and the first fall frost is September 8, giving you a growing season of approximately 88 days.

At an elevation of 5,381 feet, Routt County receives approximately 24.5 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Endive to ensure they mature before fall.

Routt County, CO (Zone 5a) Very short season
88 days
Last Spring Frost June 12
88 growing days
First Fall Frost September 8

Routt County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.9

Drainage

Well Drained

Endive Planting Risk Windows

Early Start (70% safe) ✓ Fits season (5 days to spare)
Start indoors: Apr 28 Transplant: Jun 2 🍅 Harvest: Jul 21 – Aug 25
Recommended (50%) ✓ Fits season (4 days to spare)
Start indoors: May 8 Transplant: Jun 12 🍅 Harvest: Jul 31 – Sep 4
Safe Start (90%) ✓ Fits season (6 days to spare)
Start indoors: May 21 Transplant: Jun 25 🍅 Harvest: Aug 13 – Sep 17

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 Routt County

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

Soil pH

Your soil pH (6.7–7.9) is more alkaline than Endive prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

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

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 88-day season

Sow every 5.1 weeks. Last sowing by Jul 05 to harvest before frost.

For a dedicated fall crop, sow by Jun 30.

Endive Water Budget

Plant needs
0.7″/week
Rainfall provides
1.2″/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 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 1.9" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 2.7" 0" ❄️ Dormant
May 2.8" 0" ❄️ Dormant
Jun 3" 1.5" 1.5" 🚿 Regular watering
Jul 3" 2.2" 0.8" 💧 Light watering
Aug 3" 2.2" 0.8" 💧 Light watering
Sep 3" 2.3" 0.7" 💧 Light watering
Oct 1.9" 0" ❄️ Dormant
Nov 1.5" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Routt 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 1,078 GDD Excellent fit

Endive Planting Timeline — Routt County, CO

Endive Planting Calendar

Activity When Date Range
Start Indoors May 8 May 8 – May 22
Transplant Outdoors June 12 Jun 12 – Jun 26
Direct Sow May 29 May 29 – Jun 19
Harvest July 31 Jul 31 – Sep 4
Fall Sowing June 30 Jun 30 – Jul 14

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 Fall Sowing
July Fall Sowing Harvest
August Harvest
September Harvest
October
November
December

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: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

88 days in Routt County

Growing Tips for Endive in Routt County

Direct sow Endive outdoors after June 12 in Routt 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 Routt County, CO?

Routt County is in Zone 5a with an average last frost of June 12. Plan your Endive planting based on this frost date — see the calendar above for exact timing.

What planting zone is Routt County, CO?

Routt County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 12 and first fall frost is September 8.

When should I plant Endive in Routt County, CO?

In Routt County, CO, plant Endive after the last frost (around June 12) and before the first frost (around September 8). Best results when soil holds above 50°F.

What growing zone is Routt County, CO for Endive?

Routt County sits in USDA Zone 5a. Endive grows reliably in zones 3a through 10b, so it's a good fit here.

Can Endive grow in Routt County's climate?

Yes — Endive grows well in Routt County's temperate climate. Routt County averages a 88-day frost-free season, with last frost around June 12 and first frost around September 8.

🌱

Your Routt County Garden Planner — Free

A 22-page printable planner built for Routt 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Routt County, CO. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.