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When to Plant Serviceberries in LaSalle County, IL

Serviceberries (saskatoons) are attractive native shrubs or small trees producing sweet, blueberry-like fruits. They have beautiful spring flowers and vibrant fall color.

LaSalle County, Illinois is in USDA Zone 5a. 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 523 feet, LaSalle County receives approximately 39.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Serviceberries to ensure they mature before fall.

LaSalle County, IL (Zone 5a) Moderate season
175 days
Last Spring Frost April 22
175 growing days
First Fall Frost October 14

LaSalle County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: May 8
Recommended (50%) ✓ Fits season
Transplant: May 13
Safe Start (90%) ✓ Fits season
Transplant: May 26

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 74 gal / 100 sq ft
Serviceberries needs ~11,862 GDD — county provides 2,275 GDD May not mature

Serviceberries Planting Timeline โ€” LaSalle County, IL

Serviceberries Planting Calendar

Activity When Date Range
Transplant Outdoors May 13 May 13 โ€“ May 27

ยท 120" apart ยท Rows 144" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Transplant Outdoors
June โ€”
July โ€”
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

730โ€“1095 days

Soil pH

5.5 โ€“ 7

USDA Zone

Zone 5a

Growing Season

175 days

Growing Tips for LaSalle County

Plant in well-drained soil. Minimal pruning needed beyond removing dead wood. Protect fruit from birds with netting. Berries ripen in early summer and are excellent fresh or in pies.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Serviceberries in LaSalle County, IL?

LaSalle County is in Zone 5a with an average last frost of April 22. Plan your Serviceberries planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is LaSalle County, IL?

LaSalle County, Illinois is in USDA Hardiness Zone 5a. The average last spring frost is April 22 and first fall frost is October 14.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help LaSalle County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

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Free download. Plan your entire garden season in minutes.

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