When to plant Alliums in Calhoun County, IL
The best window to plant Alliums in Calhoun County, is mid-spring–late spring, when soil warms to 50°F. Last frost typically hits April 13; first frost October 21. A second sowing from September 9 to September 23 extends the harvest into fall.
When to Plant Alliums in Calhoun 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.
Calhoun County, Illinois is in USDA Zone 6b. The average last spring frost is April 13 and the first fall frost is October 21, giving you a growing season of approximately 191 days.
At an elevation of 731 feet, Calhoun County receives approximately 32.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Alliums during the growing season.
Calhoun County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7.3
Drainage
Well Drained
Monthly Watering Guide for Alliums
Alliums needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Alliums Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3" | 1.3" | 💧 Light watering |
| May | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Jun | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Aug | 4.3" | 3" | 1.3" | 💧 Light watering |
| Sep | 4.3" | 3.3" | 1" | 💧 Light watering |
| Oct | 4.3" | 2.2" | 2.1" | 💧 Light watering |
| Nov | — | 2.4" | 0" | ❄️ Dormant |
| Dec | — | 1.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Calhoun County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Alliums Planting Timeline — Calhoun County, IL
Alliums Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Bloom | October 7 | Oct 7 – Nov 4 |
| Fall Sowing | September 9 | Sep 9 – Sep 23 |
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 | Bloom |
| November | Bloom |
| 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 6b
📆 Growing Season
191 days in Calhoun County
Growing Tips for Calhoun 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 Calhoun County, IL?
Calhoun County is in Zone 6b with an average last frost of April 13. Plan your Alliums planting based on this frost date — see the calendar above for exact timing.
What planting zone is Calhoun County, IL?
Calhoun County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 13 and first fall frost is October 21.
When should I plant Alliums in Calhoun County, IL?
In Calhoun County, IL, plant Alliums after the last frost (around April 13) and before the first frost (around October 21). Best results when soil holds above 50°F.
What growing zone is Calhoun County, IL for Alliums?
Calhoun County sits in USDA Zone 6b. Alliums grows reliably in zones 3a through 9b, so it's a good fit here.
Can Alliums grow in Calhoun County's climate?
Yes — Alliums grows well in Calhoun County's temperate climate. Calhoun County averages a 191-day frost-free season, with last frost around April 13 and first frost around October 21.
Your Calhoun County Garden Planner — Free
A 22-page printable planner built for Calhoun County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.