When to Plant Collard Greens in Adams County, ID
Your May game plan for Adams County, Idaho
Here's what deserves your attention in Adams County, Idaho this month. Everything below is tailored to Zone 6a and timed around your local frost dates.
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Harden off and plant collard greens
Frost risk is low now in Adams County, Idaho. If you've been covering beds overnight, you can stop.
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Outdoor sowing time: collard greens
Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.
June will be here before you know it — start on
- Starting indoors: collard greens
Collard greens are a heat-tolerant member of the cabbage family with large, sturdy leaves. They are a Southern staple and one of the most nutritious leafy greens.
Adams County, Idaho is in USDA Zone 6a. The average last spring frost is May 20 and the first fall frost is September 25, giving you a growing season of approximately 128 days.
At an elevation of 6,593 feet, Adams County receives approximately 20.6 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Collard Greens during the growing season.
Adams County Soil Profile
Soil Type
Loam
Soil pH
6.3-8
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 Adams County
How your county's soil matches Collard Greens's growing requirements.
Soil pH
Your soil pH (6.3–8.0) is more alkaline than Collard Greens prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Adams County is excellent for Collard Greens — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Collard Greens.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Collard Greens.
How to Plant Collard Greens
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Collard Greens
Sow every 6.3 weeks. Last sowing by Jul 12 to harvest before frost.
For a dedicated fall crop, sow by Jul 17.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Collard Greens
Collard Greens needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.
| Month | Collard Greens Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.1" | 0" | ❄️ Dormant |
| Mar | — | 1.9" | 0" | ❄️ Dormant |
| Apr | — | 2" | 0" | ❄️ Dormant |
| May | 3.5" | 2.6" | 0.9" | 💧 Light watering |
| Jun | 3.5" | 1.4" | 2.1" | 🚿 Regular watering |
| Jul | 3.5" | 2" | 1.5" | 💧 Light watering |
| Aug | 3.5" | 2.1" | 1.4" | 💧 Light watering |
| Sep | 3.5" | 1.7" | 1.8" | 🚿 Regular watering |
| Oct | — | 1.8" | 0" | ❄️ Dormant |
| Nov | — | 1.4" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Adams County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Collard Greens 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.
Collard Greens Planting Timeline — Adams County, ID
Collard Greens Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 15 | Apr 15 – Apr 29 |
| Transplant Outdoors | May 20 | May 20 – Jun 3 |
| Direct Sow | May 6 | May 6 – May 27 |
| Harvest | July 15 | Jul 15 – Sep 16 |
| Fall Sowing | July 17 | Jul 17 – Jul 31 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · 1-2 times/week
📅 Days to Maturity
55–75 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 6a
📆 Growing Season
128 days in Adams County
Growing Tips for Collard Greens in Adams County
Direct sow Collard Greens outdoors after May 20 in Adams County when soil has warmed and frost danger has passed.
Common pests for Collard Greens in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors or direct sow 4-6 weeks before last frost. Harvest lower leaves first, leaving the growing tip intact. Flavor improves after exposure to frost.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Collard Greens in Other Locations
Frequently Asked Questions
When should I plant Collard Greens in Adams County, ID?
Adams County is in Zone 6a with an average last frost of May 20. Plan your Collard Greens planting based on this frost date — see the calendar above for exact timing.
What planting zone is Adams County, ID?
Adams County, Idaho is in USDA Hardiness Zone 6a. The average last spring frost is May 20 and first fall frost is September 25.
Your Adams County Garden Planner — Free
A 24-page printable planner built for Adams 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.