When to plant Asparagus in Lee County, IL
Lee County's 175-day season only supports one Asparagus planting per year. Sow between May 6 and May 20 for the best chance at full maturity before October 14.
When to Plant Asparagus in Lee County, IL
June in the garden — Lee County, Illinois
A quick June briefing for Lee County, Illinois gardeners — what's urgent, what's next, and what can wait.
Asparagus is a long-lived perennial vegetable that produces tender spears each spring for 15-20 years once established. It requires patience but rewards with reliable harvests.
Lee County, Illinois is in USDA Zone 5b. The average last spring frost is April 22 and the first fall frost is October 14, giving you a growing season of approximately 175 days.
At an elevation of 1,010 feet, Lee County receives approximately 33.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Asparagus to ensure they mature before fall.
Lee County Soil Profile
Soil Type
Silt Loam
Soil pH
6.3-6.9
Drainage
Well Drained
Asparagus 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 Lee County
How your county's soil matches Asparagus's growing requirements.
Soil pH
Your soil pH (6.3–6.9) overlaps with Asparagus's range (6.5–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Lee County is excellent for Asparagus — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Asparagus.
Organic Matter
Organic matter is excellent (4.8%) — Asparagus will thrive.
How to Plant Asparagus
Asparagus Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Asparagus
Asparagus needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.
| Month | Asparagus Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 2" | 0" | ❄️ Dormant |
| Apr | 3.5" | 2.8" | 0.7" | 💧 Light watering |
| May | 3.5" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jun | 3.5" | 4.2" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 3.3" | 0.2" | 💧 Light watering |
| Aug | 3.5" | 3.5" | 0" | ✅ Rainfall sufficient |
| Sep | 3.5" | 2.9" | 0.6" | 💧 Light watering |
| Oct | 3.5" | 2.7" | 0.8" | 💧 Light watering |
| Nov | — | 2.7" | 0" | ❄️ Dormant |
| Dec | — | 1.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Lee County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Asparagus 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.
Asparagus Planting Timeline — Lee County, IL
Asparagus Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 6 | May 6 – May 20 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | — |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · Only during dry spells
📅 Days to Maturity
730–1095 days
🧪 Soil pH
Needs 6.5–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 5b
📆 Growing Season
175 days in Lee County
Growing Tips for Asparagus in Lee County
Direct sow Asparagus outdoors after April 22 in Lee County when soil has warmed and frost danger has passed.
Your 175.0-day growing season in Lee County is tight for Asparagus (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.
General growing tips
Plant crowns in deep trenches with compost. Do not harvest spears for the first two years to allow root establishment. Mulch heavily to suppress weeds and retain moisture.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Asparagus in Other Locations
Frequently Asked Questions
When should I plant Asparagus in Lee County, IL?
Lee County is in Zone 5b with an average last frost of April 22. Plan your Asparagus planting based on this frost date — see the calendar above for exact timing.
What planting zone is Lee County, IL?
Lee County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 22 and first fall frost is October 14.
When should I plant Asparagus in Lee County, IL?
In Lee County, IL, plant Asparagus after the last frost (around April 22) and before the first frost (around October 14). Best results when soil holds above 50°F.
What growing zone is Lee County, IL for Asparagus?
Lee County sits in USDA Zone 5b. Asparagus grows reliably in zones 3a through 10b, so it's a good fit here.
Can Asparagus grow in Lee County's climate?
Yes — Asparagus grows well in Lee County's temperate climate. Lee County averages a 175-day frost-free season, with last frost around April 22 and first frost around October 14.
Your Lee County Garden Planner — Free
A 22-page printable planner built for Lee 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.