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When to plant Alliums in Perry County County,

Plant Alliums in Perry County County, when soil hits 50°F — usually mid-spring. Continue planting through late spring for the spring crop. A second sowing from September 15 to September 29 extends the harvest into fall.

When to Plant Alliums in Perry County, IL

Perry County, Illinois Zone 7a June

June in the garden — Perry County, Illinois

Welcome to June in Zone 7a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 9
Avg. first frost October 20
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 14.6 hrs

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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.

Perry County, Illinois is in USDA Zone 7a. The average last spring frost is April 9 and the first fall frost is October 20, giving you a growing season of approximately 194 days.

At an elevation of 806 feet, Perry County receives approximately 36.9 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
Perry County, IL (Zone 7a) Moderate season
194 days
Last Spring Frost April 9
194 growing days
First Fall Frost October 20
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Perry County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7

Drainage

Well Drained

Alliums Planting Risk Windows

Early Start (70% safe) ✓ Fits season (143 days to spare)
Transplant: Apr 4 🌸 Bloom: May 2 – May 23
Recommended (50%) ✓ Fits season (145 days to spare)
Transplant: Apr 9 🌸 Bloom: May 7 – May 28
Safe Start (90%) ✓ Fits season (146 days to spare)
Transplant: Apr 20 🌸 Bloom: May 18 – Jun 8

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 Perry County

How your county's soil matches Alliums's growing requirements.

Soil pH

Your soil pH (6.1–7.0) is within Alliums's preferred range (5.5–7.5).

Soil Texture

The silt loam soil in Perry County is excellent for Alliums — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.3%) — Alliums will thrive.

How to Plant Alliums

5"
Planting Depth
7"
Between Plants
8"
Between Rows

Fall planting: Sow 5 weeks before your first frost date for a fall harvest.

Succession Planting Alliums

8
successive plantings in your 194-day season

Sow every 3.1 weeks. Last sowing by Sep 08 to harvest before frost.

For a dedicated fall crop, sow by Sep 15.

Alliums Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 1.6" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 2.2" 3.5" 0" ✅ Rainfall sufficient
May 2.2" 4.1" 0" ✅ Rainfall sufficient
Jun 2.2" 4.2" 0" ✅ Rainfall sufficient
Jul 2.2" 4.3" 0" ✅ Rainfall sufficient
Aug 2.2" 4" 0" ✅ Rainfall sufficient
Sep 2.2" 3.2" 0" ✅ Rainfall sufficient
Oct 2.2" 3.1" 0" ✅ Rainfall sufficient
Nov 2.7" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Perry 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 needs ~481 GDD — county provides 2,667 GDD Excellent fit

Alliums Planting Timeline — Perry County, IL

Alliums Planting Calendar

Activity When Date Range
Bloom October 13 Oct 13 – Nov 3
Fall Sowing September 15 Sep 15 – Sep 29

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
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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: ideal

🗺️ USDA Zone

Zone 7a

📆 Growing Season

194 days in Perry County

Growing Tips for Alliums in Perry County

Direct sow Alliums outdoors after April 09 in Perry County when soil has warmed and frost danger has passed.

Your generous 194.0-day season in Perry 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

  • Beans
  • Peas

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Alliums in Perry County, IL?

Perry County is in Zone 7a 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 Perry County, IL?

Perry County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 9 and first fall frost is October 20.

When should I plant Alliums in Perry County County, ?

In Perry County County, , plant Alliums after the last frost (around April 9) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Perry County County, for Alliums?

Perry County County sits in USDA Zone 7a. Alliums grows reliably in zones 3a through 9b, so it's a good fit here.

Can Alliums grow in Perry County County's climate?

Yes — Alliums grows well in Perry County County's temperate climate. Perry County County averages a 194-day frost-free season, with last frost around April 9 and first frost around October 20.

🌱

Your Perry County Garden Planner — Free

A 22-page printable planner built for Perry County (Zone 7a). 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 Perry County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.