When to plant Yarrow in Whiteside County County,
Aim to plant Yarrow in Whiteside County County on or after April 16; the window stays open through May 7. Whiteside County County's 183-day frost-free season gives you enough for a full main crop and a short fall succession.
When to Plant Yarrow in Whiteside County, IL
June in Whiteside County, Illinois — your action list
Your Whiteside County, Illinois garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.
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Start yarrow under lights
Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.
July will be here before you know it — start on
- First harvests: yarrow
Achillea millefolium (Yarrow) is a tough, drought-tolerant native perennial with aromatic finely-divided foliage and broad flat-topped flower clusters that serve as a landing platform for hundreds of beneficial insect species. Available in white (the species type) and a wide range of cultivars spanning yellow, gold, pink, salmon, and deep red. Spreads by rhizome to form ground-covering colonies; blooms from late spring through midsummer with reblooming into fall if deadheaded. Exceptional in hot, dry sites where other perennials fail.
Whiteside County, Illinois is in USDA Zone 5b. The average last spring frost is April 16 and the first fall frost is October 16, giving you a growing season of approximately 183 days.
At an elevation of 682 feet, Whiteside County receives approximately 30.2 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.
Whiteside County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-6.7
Drainage
Well Drained
Yarrow 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 Whiteside County
How your county's soil matches Yarrow's growing requirements.
Soil pH
Your soil pH (5.9–6.7) is within Yarrow's preferred range (5.5–7.0).
Soil Texture
The silt loam soil in Whiteside County is excellent for Yarrow — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (4.0%). Annual compost additions will help Yarrow.
How to Plant Yarrow
Succession Planting Yarrow
Sow every 6.9 weeks. Last sowing by Jul 18 to harvest before frost.
Yarrow Water Budget
Monthly Watering Guide for Yarrow
Yarrow 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 | Yarrow Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.2" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 2.3" | 0" | ❄️ Dormant |
| Apr | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.1" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2.8" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.3" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.1" | 0" | ❄️ Dormant |
| Dec | — | 1.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Whiteside County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Yarrow 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.
Yarrow Planting Timeline — Whiteside County, IL
Yarrow Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 12 | Feb 12 – Feb 26 |
| Transplant Outdoors | April 30 | Apr 30 – May 14 |
| Direct Sow | April 16 | Apr 16 – May 7 |
| Bloom | July 9 | Jul 9 – Oct 22 |
· 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | — |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 5.5–7 · Your soil: ideal
🗺️ USDA Zone
Zone 5b
📆 Growing Season
183 days in Whiteside County
Growing Tips for Yarrow in Whiteside County
Direct sow Yarrow outdoors after April 16 in Whiteside County when soil has warmed and frost danger has passed.
Common pests for Yarrow in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 8–10 weeks before last frost; seeds need light for germination — press onto soil surface, do not cover. Direct sow after last frost or divide established clumps in spring or fall. Thrives in poor, well-drained soil — rich soil and high fertility cause floppy stems and reduce flower count. Avoid overwatering; excellent drought tolerance once established. Deadhead spent clusters to encourage rebloom. Divide every 2–3 years to prevent center die-out and control spread. Year 2+ plants bloom most heavily; first-year plants may produce limited flowers. Dried flowers retain color well for arrangements.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Yarrow in Other Locations
Frequently Asked Questions
When should I plant Yarrow in Whiteside County, IL?
Whiteside County is in Zone 5b with an average last frost of April 16. Plan your Yarrow planting based on this frost date — see the calendar above for exact timing.
What planting zone is Whiteside County, IL?
Whiteside County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 16 and first fall frost is October 16.
When should I plant Yarrow in Whiteside County County, ?
In Whiteside County County, , plant Yarrow after the last frost (around April 16) and before the first frost (around October 16). Best results when soil holds above 50°F.
What growing zone is Whiteside County County, for Yarrow?
Whiteside County County sits in USDA Zone 5b. Yarrow grows reliably in zones 3a through 9b, so it's a good fit here.
Can Yarrow grow in Whiteside County County's climate?
Yes — Yarrow grows well in Whiteside County County's temperate climate. Whiteside County County averages a 183-day frost-free season, with last frost around April 16 and first frost around October 16.
Your Whiteside County Garden Planner — Free
A 22-page printable planner built for Whiteside 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.