When to Plant Yarrow in LaSalle County, IL
Yarrow is a drought-tolerant perennial herb with feathery foliage and flat-topped flower clusters in white, yellow, pink, or red. It attracts beneficial insects and is used in herbal medicine.
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 84°F, so choose short-season varieties of Yarrow to ensure they mature before fall.
LaSalle County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.9
Drainage
Well Drained
Plant 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.
Plant Water Budget
Yarrow Planting Timeline — LaSalle County, IL
Yarrow Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 29 | Apr 29 – May 13 |
| Harvest | July 29 | Jul 29 – Oct 14 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors |
| May | Transplant Outdoors |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Low — drought tolerant
Days to Maturity
90–120 days
Soil pH
5.5 – 7
USDA Zone
Zone 5a
Growing Season
175 days
Growing Tips for LaSalle County
Direct sow or start from divisions. Yarrow thrives in poor soil and is very drought-tolerant. Deadhead to encourage reblooming. Divide clumps every 3 years.
Companion Planting
Good Companions
Level Up Your Garden
Yarrow in Other Locations
Frequently Asked Questions
When should I plant Yarrow in LaSalle County, IL?
LaSalle County is in Zone 5a with an average last frost of April 22. Plan your Yarrow planting based on this frost date — 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.
Plan Your Garden with Confidence
Get our free Garden Planner — 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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