When to plant Collard Greens in New Castle County County,
Aim to plant Collard Greens in New Castle County County on or after March 23; the window stays open through April 13. New Castle County County's 208-day frost-free season gives you enough for a full main crop and a short fall succession. A second sowing from August 22 to September 5 extends the harvest into fall.
When to Plant Collard Greens in New Castle County, DE
This month in New Castle County, Delaware
June is a pivotal month for New Castle County, Delaware gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Pick collard greens
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
Get ahead of July
- First harvests: 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.
New Castle County, Delaware is in USDA Zone 7b. The average last spring frost is April 6 and the first fall frost is October 31, giving you a growing season of approximately 208 days.
At an elevation of 415 feet, New Castle County receives approximately 38.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Collard Greens during the growing season.
New Castle County Soil Profile
Soil Type
Silt Loam
Soil pH
5.2-7.1
Drainage
Well Drained
Collard Greens 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 New Castle County
How your county's soil matches Collard Greens's growing requirements.
Soil pH
Your soil pH (5.2–7.1) overlaps with Collard Greens's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in New Castle County is excellent for Collard Greens — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.0%). 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.
Collard Greens 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 | — | 2.4" | 0" | ❄️ Dormant |
| Feb | — | 2.7" | 0" | ❄️ Dormant |
| Mar | — | 3.4" | 0" | ❄️ Dormant |
| Apr | 3.5" | 3.2" | 0.3" | 💧 Light watering |
| May | 3.5" | 3.3" | 0.2" | 💧 Light watering |
| Jun | 3.5" | 3.3" | 0.2" | 💧 Light watering |
| Jul | 3.5" | 4.1" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 3.2" | 0.3" | 💧 Light watering |
| Sep | 3.5" | 3.1" | 0.4" | 💧 Light watering |
| Oct | 3.5" | 3.2" | 0.3" | 💧 Light watering |
| Nov | — | 3.4" | 0" | ❄️ Dormant |
| Dec | — | 2.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in New Castle 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 — New Castle County, DE
Collard Greens Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 2 | Mar 2 – Mar 16 |
| Transplant Outdoors | April 6 | Apr 6 – Apr 20 |
| Direct Sow | March 23 | Mar 23 – Apr 13 |
| Harvest | June 1 | Jun 1 – Aug 3 |
| Fall Sowing | August 22 | Aug 22 – Sep 5 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · Only during dry spells
📅 Days to Maturity
55–75 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 7b
📆 Growing Season
208 days in New Castle County
Growing Tips for Collard Greens in New Castle County
Direct sow Collard Greens outdoors after April 06 in New Castle 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 New Castle County, DE?
New Castle County is in Zone 7b with an average last frost of April 6. Plan your Collard Greens planting based on this frost date — see the calendar above for exact timing.
What planting zone is New Castle County, DE?
New Castle County, Delaware is in USDA Hardiness Zone 7b. The average last spring frost is April 6 and first fall frost is October 31.
When should I plant Collard Greens in New Castle County County, ?
In New Castle County County, , plant Collard Greens after the last frost (around April 6) and before the first frost (around October 31). Best results when soil holds above 50°F.
What growing zone is New Castle County County, for Collard Greens?
New Castle County County sits in USDA Zone 7b. Collard Greens grows reliably in zones 2a through 11b, so it's a good fit here.
Can Collard Greens grow in New Castle County County's climate?
Yes — Collard Greens grows well in New Castle County County's temperate climate. New Castle County County averages a 208-day frost-free season, with last frost around April 6 and first frost around October 31.
Your New Castle County Garden Planner — Free
A 22-page printable planner built for New Castle County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.