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When to plant Alliums in Edwards County, IL

In Edwards County, plant Alliums in spring between mid-spring and late spring, once soil temps hold above 50°F. Edwards County's last frost averages April 9, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between September 16 and September 30 — roughly 28–42 days before the first frost on October 28.

When to Plant Alliums in Edwards 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.

Edwards County, Illinois is in USDA Zone 6b. The average last spring frost is April 9 and the first fall frost is October 28, giving you a growing season of approximately 202 days.

At an elevation of 1,374 feet, Edwards County receives approximately 35.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Alliums during the growing season.

Bulb Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Edwards County, IL (Zone 6b) Long season
202 days
Last Spring Frost April 9
202 growing days
First Fall Frost October 28

Edwards County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.2

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 1.6" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 5" 0" ✅ Rainfall sufficient
Jul 4.3" 3.9" 0.4" 💧 Light watering
Aug 4.3" 3.4" 0.9" 💧 Light watering
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 2.9" 1.4" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Edwards County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Alliums Planting Timeline — Edwards County, IL

Alliums Planting Calendar

Activity When Date Range
Bloom October 14 Oct 14 – Nov 11
Fall Sowing September 16 Sep 16 – Sep 30

Plant 5" deep · 7" apart · Rows 8" apart

Month-by-Month Timeline

MonthActivities
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

202 days in Edwards County

Growing Tips for Edwards 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

  • Beans
  • Peas

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Alliums in Edwards County, IL?

Edwards County is in Zone 6b with an average last frost of April 9. Plan your Alliums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Edwards County, IL?

Edwards County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 9 and first fall frost is October 28.

When should I plant Alliums in Edwards County, IL?

In Edwards County, IL, plant Alliums after the last frost (around April 9) and before the first frost (around October 28). Best results when soil holds above 50°F.

What growing zone is Edwards County, IL for Alliums?

Edwards 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 Edwards County's climate?

Yes — Alliums grows well in Edwards County's temperate climate. Edwards County averages a 202-day frost-free season, with last frost around April 9 and first frost around October 28.

🌱

Your Edwards County Garden Planner — Free

A 22-page printable planner built for Edwards 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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Edwards County, IL. Local conditions may vary. Last updated: July 2026.

Sources & credits

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