When to plant Alliums in Bear, DE
Alliums planted in Bear between mid-spring and late spring matures in 28–42 days — well before the October 31 first frost. A second sowing from September 26 to October 10 extends the harvest into fall.
When to Plant Alliums in Bear, DE
Top priorities for New Castle County, Delaware gardeners in July
Here's what deserves your attention in New Castle County, Delaware this month. Everything below is tailored to Zone 7b and timed around your local frost dates.
Ornamental alliums (Allium spp.) bridge the gap between spring and summer with their striking globe-shaped flower heads in shades of purple, violet, white, and pink. Blooming after tulips have faded, they extend the spring display well into early summer. 'Gladiator', 'Globemaster', and 'Purple Sensation' produce softball-sized heads on 18–36 inch stems, while smaller species create charming accents at border fronts. Deer and rodents shun them completely due to the characteristic onion scent. Dried seed heads provide architectural interest into fall.
Bear, 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 Alliums during the growing season.
Bear Soil Profile
Soil Type
Silt Loam
Soil pH
5.2-7.1
Drainage
Well Drained
Alliums 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 Bear
How your county's soil matches Alliums's growing requirements.
Soil pH
Your soil pH (5.2–7.1) overlaps with Alliums's range (5.5–7.5), though not a perfect match.
Soil Texture
The silt loam soil in New Castle County is excellent for Alliums — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.0%). Annual compost additions will help Alliums.
How to Plant Alliums
Fall planting: Sow 5 weeks before your first frost date for a fall harvest.
Succession Planting Alliums
Sow every 3.1 weeks. Last sowing by Sep 19 to harvest before frost.
For a dedicated fall crop, sow by Sep 26.
Alliums Water Budget
Monthly Watering Guide for Alliums
Alliums needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.
| Month | Alliums Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 2.4" | 0" | ❄️ Dormant |
| Feb | — | 2.7" | 0" | ❄️ Dormant |
| Mar | — | 3.4" | 0" | ❄️ Dormant |
| Apr | 2.2" | 3.2" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 4.1" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.2" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.1" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.2" | 0" | ✅ Rainfall sufficient |
| 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.
Alliums 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.
Alliums Planting Timeline — Bear, DE
Alliums Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Bloom | October 24 | Oct 24 – Nov 14 |
| Fall Sowing | September 26 | Sep 26 – Oct 10 |
Plant 5" deep · 7" apart · Rows 8" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | — |
| July | — |
| August | — |
| September | Fall Sowing |
| October | Fall Sowing Bloom |
| November | Bloom |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
28–42 days
🧪 Soil pH
Needs 5.5–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 7b
📆 Growing Season
208 days in New Castle County
Growing Tips for Alliums in Bear
Direct sow Alliums outdoors after April 06 in New Castle County when soil has warmed and frost danger has passed.
Your generous 208.0-day season in New Castle County allows multiple plantings of Alliums. Sow every 14.0 days for continuous harvest.
Common pests for Alliums in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.
General growing tips
Plant bulbs in fall, 3–4 times as deep as the bulb diameter (typically 4–6 inches for large types, 3 inches for small species). Space 6–8 inches apart for standard cultivars. Foliage often looks untidy as it dies back before bloom — plant around perennials that will conceal the yellowing leaves. Excellent drainage is essential; alliums rot in wet soils. Leave bulbs in place for naturalization; divide every 3–4 years when clusters become congested. Deadhead spent globes or leave for ornamental seedheads and self-sowing.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Alliums in Other Locations
When should I plant Alliums in Bear, DE?
In Bear, DE, plant Alliums 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 Bear, DE for Alliums?
Bear sits in USDA Zone 7b. Alliums grows reliably in zones 3a through 9b, so it's a good fit here.
Can Alliums grow in Bear's climate?
Yes — Alliums grows well in Bear's temperate climate. Bear 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.