When to Plant Yarrow in Washington County, RI
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.
Washington County, Rhode Island is in USDA Zone 6b. The average last spring frost is April 23 and the first fall frost is October 21, giving you a growing season of approximately 181 days.
At an elevation of 519 feet, Washington County receives approximately 41.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Yarrow during the growing season.
Washington County Soil Profile
Soil Type
Silt Loam
Soil pH
4.9-6.6
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 — Washington County, RI
Yarrow Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 30 | Apr 30 – May 14 |
| Harvest | July 30 | Jul 30 – Oct 15 |
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 6b
Growing Season
181 days
Growing Tips for Washington 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 Washington County, RI?
Washington County is in Zone 6b with an average last frost of April 23. Plan your Yarrow planting based on this frost date — see the calendar above for exact timing.
What planting zone is Washington County, RI?
Washington County, Rhode Island is in USDA Hardiness Zone 6b. The average last spring frost is April 23 and first fall frost is October 21.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Washington County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.
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