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When to Plant Crosne in Costilla County, CO

Costilla County, Colorado Zone 5b May

Your May game plan for Costilla County, Colorado

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

Avg. last frost June 8
Avg. first frost September 16
Soil temp (4") 43°F
Watering High
Pest pressure Low
Daylight 14 hrs
  1. Outdoor sowing time: crosne

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

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Crosne (Chinese artichoke) produces small, segmented white tubers with a crunchy texture and mild artichoke-nutty flavor. They are a rare delicacy in French cuisine.

Costilla County, Colorado is in USDA Zone 5b. The average last spring frost is June 8 and the first fall frost is September 16, giving you a growing season of approximately 100 days.

At an elevation of 5,598 feet, Costilla County receives approximately 21 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Crosne during the growing season.

Costilla County, CO (Zone 5b) Short season
100 days
Last Spring Frost June 8
100 growing days
First Fall Frost September 16

Costilla County Soil Profile

Soil Type

Loam

Soil pH

6.2-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 30 🍅 Harvest: Oct 31 – Nov 14
Recommended (50%) ✗ May not fit
Transplant: Jun 8 🍅 Harvest: Nov 9 – Nov 23
Safe Start (90%) ✗ May not fit
Transplant: Jun 19 🍅 Harvest: Nov 20 – Dec 4

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 Costilla County

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

Soil pH

Your soil pH (6.2–8.3) is more alkaline than Crosne prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Crosne.

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Crosne.

How to Plant Crosne

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

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 446 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Crosne

Crosne needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Crosne Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2" 0" ❄️ Dormant
May 2.5" 0" ❄️ Dormant
Jun 4.3" 1.3" 3" 🚿 Regular watering
Jul 4.3" 2" 2.3" 🚿 Regular watering
Aug 4.3" 2.5" 1.8" 💧 Light watering
Sep 4.3" 1.7" 2.6" 🚿 Regular watering
Oct 1.9" 0" ❄️ Dormant
Nov 1.3" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

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

Crosne 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.

Crosne needs ~2,538 GDD — county provides 1,450 GDD May not mature

Crosne Planting Timeline — Costilla County, CO

Crosne Planting Calendar

Activity When Date Range
Direct Sow May 25 May 25 – Jun 15
Harvest October 26 Oct 26 – Nov 9
Fall Sowing July 8 Jul 8 – Jul 22

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Direct Sow
June Direct Sow
July Fall Sowing
August
September
October Harvest
November Harvest
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

150–200 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5b

📆 Growing Season

100 days in Costilla County

Growing Tips for Crosne in Costilla County

Direct sow Crosne outdoors after June 08 in Costilla County when soil has warmed and frost danger has passed.

Your 100.0-day growing season in Costilla County is tight for Crosne (150.0-200.0 days to maturity). Start indoors and choose early-maturing varieties.

Costilla County receives only 21" of rain annually. Crosne needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Plant tubers 3 inches deep in spring. Mark the location well as plants die back. Harvest in late fall after frost. Leave some tubers in ground for next year. Very labor-intensive to harvest.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Crosne in Costilla County, CO?

Costilla County is in Zone 5b with an average last frost of June 8. Plan your Crosne planting based on this frost date — see the calendar above for exact timing.

What planting zone is Costilla County, CO?

Costilla County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is June 8 and first fall frost is September 16.

🌱

Your Costilla County Garden Planner — Free

A 24-page printable planner built for Costilla County (Zone 5b). 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 Costilla County, CO. 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.