When to plant Crosne in Boulder County, CO
Spring Crosne in Boulder County goes in April 30–May 21, once nighttime temps stop dipping near freezing. A second sowing from July 18 to August 1 extends the harvest into fall.
When to Plant Crosne in Boulder County, CO
Boulder County, Colorado gardeners: here's your July plan
Your garden in Boulder County, Colorado is working on a schedule, even when you're not. Here's where you should be this July.
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Plant your fall garden: crosne
A row cover ready in the garage extends your harvest by weeks once the nights turn cold.
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.
Boulder County, Colorado is in USDA Zone 6a. The average last spring frost is May 14 and the first fall frost is September 26, giving you a growing season of approximately 135 days.
At an elevation of 7,657 feet, Boulder County receives approximately 22.2 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Crosne during the growing season.
Boulder County Soil Profile
Soil Type
Loam
Soil pH
6.7-8
Drainage
Well Drained
Crosne 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 Boulder County
How your county's soil matches Crosne's growing requirements.
Soil pH
Your soil pH (6.7–8.0) is more alkaline than Crosne prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Boulder 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 (2.3%). Annual compost additions will help Crosne.
How to Plant Crosne
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Crosne Water Budget
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 | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 1.8" | 0" | ❄️ Dormant |
| Apr | — | 2.2" | 0" | ❄️ Dormant |
| May | 4.3" | 3" | 1.3" | 💧 Light watering |
| Jun | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Jul | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Aug | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Sep | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Oct | — | 1.9" | 0" | ❄️ Dormant |
| Nov | — | 1.4" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Boulder 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 Planting Timeline — Boulder County, CO
Crosne Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 30 | Apr 30 – May 21 |
| Harvest | October 1 | Oct 1 – Nov 12 |
| Fall Sowing | July 18 | Jul 18 – Aug 1 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Direct Sow |
| May | Direct Sow |
| June | — |
| July | Fall Sowing |
| August | Fall Sowing |
| September | — |
| October | Harvest |
| November | Harvest |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 2-3 times/week
📅 Days to Maturity
150–200 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 6a
📆 Growing Season
135 days in Boulder County
Growing Tips for Crosne in Boulder County
Direct sow Crosne outdoors after May 14 in Boulder County when soil has warmed and frost danger has passed.
Your 135.0-day growing season in Boulder County is tight for Crosne (150.0-200.0 days to maturity). Start indoors and choose early-maturing varieties.
Boulder County receives only 22" 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 →
Crosne in Other Locations
Frequently Asked Questions
When should I plant Crosne in Boulder County, CO?
Boulder County is in Zone 6a with an average last frost of May 14. Plan your Crosne planting based on this frost date — see the calendar above for exact timing.
What planting zone is Boulder County, CO?
Boulder County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 14 and first fall frost is September 26.
When should I plant Crosne in Boulder County, CO?
In Boulder County, CO, plant Crosne after the last frost (around May 14) and before the first frost (around September 26). Best results when soil holds above 50°F.
What growing zone is Boulder County, CO for Crosne?
Boulder County sits in USDA Zone 6a. Crosne grows reliably in zones 4a through 9b, so it's a good fit here.
Can Crosne grow in Boulder County's climate?
Yes — Crosne grows well in Boulder County's temperate climate. Boulder County averages a 135-day frost-free season, with last frost around May 14 and first frost around September 26.
Your Boulder County Garden Planner — Free
A 22-page printable planner built for Boulder County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.