When to Plant Pac Choi in Grand County, CO
Top priorities for Grand County, Colorado gardeners in May
May is a pivotal month for Grand County, Colorado gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Transplant pac choi outside
Frost risk is low now in Grand County, Colorado. If you've been covering beds overnight, you can stop.
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Direct-sow pac choi
Mark the row. Birds and stray feet both have opinions about unmarked beds.
Pac choi (baby bok choy) is a compact variety of Chinese cabbage with tender leaves and crisp stems. It grows quickly and is ideal for containers and small spaces.
Grand County, Colorado is in USDA Zone 5a. The average last spring frost is May 28 and the first fall frost is September 19, giving you a growing season of approximately 114 days.
At an elevation of 5,397 feet, Grand County receives approximately 22.2 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Pac Choi to ensure they mature before fall.
Grand County Soil Profile
Soil Type
Loam
Soil pH
6.7-8.3
Drainage
Well Drained
Plant 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 Grand County
How your county's soil matches Pac Choi's growing requirements.
Soil pH
Your soil pH (6.7–8.3) overlaps with Pac Choi's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Grand County is excellent for Pac Choi — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Pac Choi is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Pac Choi.
How to Plant Pac Choi
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Pac Choi
Sow every 4.6 weeks. Last sowing by Jul 26 to harvest before frost.
For a dedicated fall crop, sow by Jul 11.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Pac Choi
Pac Choi needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.
| Month | Pac Choi Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 1.9" | 0" | ❄️ Dormant |
| Apr | — | 2.1" | 0" | ❄️ Dormant |
| May | 6.5" | 3" | 3.5" | 🚿 Regular watering |
| Jun | 6.5" | 1.5" | 5" | 🚿 Regular watering |
| Jul | 6.5" | 2" | 4.5" | 🚿 Regular watering |
| Aug | 6.5" | 2.3" | 4.2" | 🚿 Regular watering |
| Sep | 6.5" | 1.6" | 4.9" | 🚿 Regular watering |
| Oct | — | 2.2" | 0" | ❄️ Dormant |
| Nov | — | 1.5" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Grand County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Pac Choi 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.
Pac Choi Planting Timeline — Grand County, CO
Pac Choi Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 23 | Apr 23 – May 7 |
| Transplant Outdoors | May 28 | May 28 – Jun 11 |
| Direct Sow | May 14 | May 14 – Jun 4 |
| Harvest | July 9 | Jul 9 – Aug 6 |
| Fall Sowing | July 11 | Jul 11 – Jul 25 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Start Indoors Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1.5"/week · 2-3 times/week
📅 Days to Maturity
40–55 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 5a
📆 Growing Season
114 days in Grand County
Growing Tips for Pac Choi in Grand County
Direct sow Pac Choi outdoors after May 28 in Grand County when soil has warmed and frost danger has passed.
Common pests for Pac Choi in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
Grand County receives only 22" of rain annually. Pac Choi needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Direct sow in spring or fall. Grows best in cool weather. Space 6 inches apart for baby pac choi. Harvest whole plants or cut outer leaves as needed.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Pac Choi in Other Locations
Frequently Asked Questions
When should I plant Pac Choi in Grand County, CO?
Grand County is in Zone 5a with an average last frost of May 28. Plan your Pac Choi planting based on this frost date — see the calendar above for exact timing.
What planting zone is Grand County, CO?
Grand County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is May 28 and first fall frost is September 19.
Your Grand County Garden Planner — Free
A 24-page printable planner built for Grand 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.