When to Plant Collard Greens in Jefferson County, AL
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.
Jefferson County, Alabama is in USDA Zone 7b. The average last spring frost is March 31 and the first fall frost is October 31, giving you a growing season of approximately 214 days.
At an elevation of 408 feet, Jefferson County receives approximately 48 inches of rainfall annually with predominantly clay loam soil. Summer highs average 94°F, providing good warmth for Collard Greens during the growing season. Clay soil retains moisture well for Collard Greens, but amend with compost to improve drainage and prevent root rot.
Jefferson County Soil Profile
Soil Type
Clay Loam
Soil pH
5.7-6.8
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 Jefferson County
How your county's soil matches Collard Greens's growing requirements.
Soil pH
Your soil pH (5.7–6.8) overlaps with Collard Greens's range (6.0–7.0), though not a perfect match.
Soil Texture
The clay loam soil in Jefferson 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 Aug 17 to harvest before frost.
For a dedicated fall crop, sow by Aug 22.
Plant Water Budget
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 | — | 4.3" | 0" | ❄️ Dormant |
| Feb | — | 4.2" | 0" | ❄️ Dormant |
| Mar | 3.5" | 4.9" | 0" | ✅ Rainfall sufficient |
| Apr | 3.5" | 3.9" | 0" | ✅ Rainfall sufficient |
| May | 3.5" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jun | 3.5" | 4.2" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 4.2" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 4.4" | 0" | ✅ Rainfall sufficient |
| Sep | 3.5" | 3.2" | 0.3" | 💧 Light watering |
| Oct | 3.5" | 3.3" | 0.2" | 💧 Light watering |
| Nov | — | 3.3" | 0" | ❄️ Dormant |
| Dec | — | 3.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Oct in Jefferson 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 — Jefferson County, AL
Collard Greens Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 24 | Feb 24 – Mar 10 |
| Transplant Outdoors | March 31 | Mar 31 – Apr 14 |
| Direct Sow | March 17 | Mar 17 – Apr 7 |
| Harvest | May 26 | May 26 – Jul 28 |
| Fall Sowing | August 22 | Aug 22 – Sep 5 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · Natural rainfall sufficient
📅 Days to Maturity
55–75 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 7b
📆 Growing Season
214 days in Jefferson County
Growing Tips for Collard Greens in Jefferson County
Direct sow Collard Greens outdoors after March 31 in Jefferson County when soil has warmed and frost danger has passed.
With Jefferson County's clay soil (34% clay), work in 3-4 inches of compost before planting Collard Greens. Avoid tilling when soil is wet to prevent compaction.
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
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Collard Greens in Other Locations
Frequently Asked Questions
When should I plant Collard Greens in Jefferson County, AL?
Jefferson County is in Zone 7b with an average last frost of March 31. Plan your Collard Greens planting based on this frost date — see the calendar above for exact timing.
What planting zone is Jefferson County, AL?
Jefferson County, Alabama is in USDA Hardiness Zone 7b. The average last spring frost is March 31 and first fall frost is October 31.
Plan Your Garden with Confidence
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