When to plant Alliums in Winnebago County, IL
Plant Alliums in Winnebago County, when soil hits 50°F — usually mid-spring. Continue planting through late spring for the spring crop. A second sowing from August 31 to September 14 extends the harvest into fall.
When to Plant Alliums in Winnebago County, IL
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.
Winnebago County, Illinois is in USDA Zone 5b. The average last spring frost is April 26 and the first fall frost is October 12, giving you a growing season of approximately 169 days.
At an elevation of 1,318 feet, Winnebago County receives approximately 38.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Alliums during the growing season.
Winnebago County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Alliums Planting Timeline — Winnebago County, IL
Alliums Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Bloom | October 5 | Oct 5 – Oct 26 |
| Fall Sowing | August 31 | Aug 31 – Sep 14 |
Plant 5" deep · 7" apart · Rows 8" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | — |
| July | — |
| August | Fall Sowing |
| September | Fall Sowing |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Low — drought tolerant
📅 Days to Maturity
28–42 days
🧪 Soil pH
Needs 5.5–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 5b
📆 Growing Season
169 days in Winnebago County
Growing Tips for Winnebago County
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
Frequently Asked Questions
When should I plant Alliums in Winnebago County, IL?
Winnebago County is in Zone 5b with an average last frost of April 26. Plan your Alliums planting based on this frost date — see the calendar above for exact timing.
What planting zone is Winnebago County, IL?
Winnebago County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 26 and first fall frost is October 12.
When should I plant Alliums in Winnebago County, IL?
In Winnebago County, IL, plant Alliums after the last frost (around April 26) and before the first frost (around October 12). Best results when soil holds above 50°F.
What growing zone is Winnebago County, IL for Alliums?
Winnebago County sits in USDA Zone 5b. Alliums grows reliably in zones 3a through 9b, so it's a good fit here.
Can Alliums grow in Winnebago County's climate?
Yes — Alliums grows well in Winnebago County's temperate climate. Winnebago County averages a 169-day frost-free season, with last frost around April 26 and first frost around October 12.
Your Winnebago County Garden Planner — Free
A 22-page printable planner built for Winnebago County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.