When to plant Garlic in Winnebago County, IL
Garlic planted in Winnebago County between mid-spring and late spring matures in 90–240 days — well before the October 12 first frost. A second sowing from August 31 to September 14 extends the harvest into fall.
When to Plant Garlic in Winnebago County, IL
This month in Winnebago County, Illinois
Here's what deserves your attention in Winnebago County, Illinois this month. Everything below is tailored to Zone 5b and timed around your local frost dates.
Coming up in August — start thinking about
- Fall sowing: garlic
Garlic is a pungent allium planted in fall and harvested the following summer. Hardneck varieties produce edible flower stalks (scapes) and are more cold-hardy.
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 Garlic during the growing season.
Winnebago County Soil Profile
Soil Type
Silt Loam
Soil pH
6.3-7.3
Drainage
Well Drained
Garlic 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 Winnebago County
How your county's soil matches Garlic's growing requirements.
Soil pH
Your soil pH (6.3–7.3) is within Garlic's preferred range (6.0–7.5).
Soil Texture
The silt loam soil in Winnebago County is excellent for Garlic — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.1%) — Garlic will thrive.
How to Plant Garlic
Fall planting: Sow 6 weeks before your first frost date for a fall harvest.
Garlic Water Budget
Monthly Watering Guide for Garlic
Garlic 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 | Garlic Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 4.7" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.6" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 4" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.6" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.8" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.8" | 0" | ❄️ Dormant |
| Dec | — | 2.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Winnebago County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Garlic 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.
Garlic Planting Timeline — Winnebago County, IL
Garlic Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Harvest | November 30 | Nov 30 – Feb 15 |
| Fall Sowing | August 31 | Aug 31 – Sep 14 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Harvest |
| February | Harvest |
| March | — |
| April | — |
| May | — |
| June | — |
| July | — |
| August | Fall Sowing |
| September | Fall Sowing |
| October | — |
| November | Harvest |
| December | Harvest |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
90–240 days
🧪 Soil pH
Needs 6–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 5b
📆 Growing Season
169 days in Winnebago County
Growing Tips for Garlic in Winnebago County
Direct sow Garlic outdoors after April 26 in Winnebago County when soil has warmed and frost danger has passed.
Your 169.0-day growing season in Winnebago County is tight for Garlic (90.0-240.0 days to maturity). Start indoors and choose early-maturing varieties.
Common pests for Garlic in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.
General growing tips
Plant individual cloves pointed end up in fall, 6 weeks before ground freezes. Mulch heavily with straw. Harvest when lower leaves begin to brown but 5-6 green leaves remain.
Companion Planting
Good Companions
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Check more plant combinations with our Companion Planting Checker →
Garlic in Other Locations
Frequently Asked Questions
When should I plant Garlic in Winnebago County, IL?
Winnebago County is in Zone 5b with an average last frost of April 26. Plan your Garlic 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 Garlic in Winnebago County, IL?
In Winnebago County, IL, plant Garlic 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 Garlic?
Winnebago County sits in USDA Zone 5b. Garlic grows reliably in zones 3a through 9b, so it's a good fit here.
Can Garlic grow in Winnebago County's climate?
Yes — Garlic 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.