When to plant Leeks in Delmar, DE
Delmar's spring Leeks window runs March 20 through April 10. most warm-season crops establish quickly once soil holds above 60°F. A second sowing from August 29 to September 12 extends the harvest into fall.
When to Plant Leeks in Delmar, DE
June to-do list for Sussex County, Delaware
Welcome to June in Zone 7b. These are the moves that will have the biggest impact on your growing season.
Coming up in July — start thinking about
- First harvests: leeks
Leeks are a mild, sweet allium that produces long white shanks. They are more refined than onions and are a key ingredient in soups, stews, and gratins.
Delmar, Delaware is in USDA Zone 7b. The average last spring frost is April 3 and the first fall frost is November 7, giving you a growing season of approximately 218 days.
At an elevation of 1,090 feet, Sussex County receives approximately 46 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Leeks during the growing season.
Delmar Soil Profile
Soil Type
Silt Loam
Soil pH
5.6-6.5
Drainage
Well Drained
Leeks 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 Delmar
How your county's soil matches Leeks's growing requirements.
Soil pH
Your soil pH (5.6–6.5) overlaps with Leeks's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Sussex County is excellent for Leeks — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.8%). Annual compost additions will help Leeks.
How to Plant Leeks
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Leeks Water Budget
Monthly Watering Guide for Leeks
Leeks 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 | Leeks Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.5" | 0" | ❄️ Dormant |
| Feb | — | 3.5" | 0" | ❄️ Dormant |
| Mar | — | 3.9" | 0" | ❄️ Dormant |
| Apr | 3.5" | 3.7" | 0" | ✅ Rainfall sufficient |
| May | 3.5" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jun | 3.5" | 3.7" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 5.3" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 4.1" | 0" | ✅ Rainfall sufficient |
| Sep | 3.5" | 3.9" | 0" | ✅ Rainfall sufficient |
| Oct | 3.5" | 3.4" | 0.1" | 💧 Light watering |
| Nov | 3.5" | 3.2" | 0.3" | 💧 Light watering |
| Dec | — | 3.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in Sussex County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Leeks 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.
Leeks Planting Timeline — Delmar, DE
Leeks Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 27 | Feb 27 – Mar 13 |
| Transplant Outdoors | April 3 | Apr 3 – Apr 17 |
| Direct Sow | March 20 | Mar 20 – Apr 10 |
| Harvest | July 3 | Jul 3 – Sep 18 |
| Fall Sowing | August 29 | Aug 29 – Sep 12 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | — |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | Fall Sowing Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · Natural rainfall sufficient
📅 Days to Maturity
90–150 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 7b
📆 Growing Season
218 days in Sussex County
Growing Tips for Leeks in Delmar
Direct sow Leeks outdoors after April 03 in Sussex County when soil has warmed and frost danger has passed.
Common pests for Leeks in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 10-12 weeks before last frost. Transplant into trenches and hill soil around stems as they grow to increase the white portion. Harvest as needed.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Leeks in Other Locations
When should I plant Leeks in Delmar, DE?
In Delmar, DE, plant Leeks after the last frost (around April 3) and before the first frost (around November 7). Best results when soil holds above 50°F.
What growing zone is Delmar, DE for Leeks?
Delmar sits in USDA Zone 7b. Leeks grows reliably in zones 3a through 10b, so it's a good fit here.
Can Leeks grow in Delmar's climate?
Yes — Leeks grows well in Delmar's temperate climate. Delmar averages a 218-day frost-free season, with last frost around April 3 and first frost around November 7.
Your Sussex County Garden Planner — Free
A 22-page printable planner built for Sussex 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.