When to Plant Yarrow in Somervell County, TX
Top priorities for Somervell County, Texas gardeners in May
Welcome to May in Zone 8b. These are the moves that will have the biggest impact on your growing season.
June will be here before you know it — start on
- First harvests: yarrow
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.
Somervell County, Texas is in USDA Zone 8b. The average last spring frost is March 19 and the first fall frost is November 12, giving you a growing season of approximately 238 days.
At an elevation of 4,773 feet, Somervell County receives approximately 64.7 inches of rainfall annually with predominantly clay soil. Summer highs average 90°F, providing good warmth for Yarrow during the growing season. Clay soil retains moisture well for Yarrow, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Yarrow root diseases.
Somervell County Soil Profile
Soil Type
Clay
Soil pH
7.2-7.8
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.
Soil Compatibility in Somervell County
How your county's soil matches Yarrow's growing requirements.
Soil pH
Your soil pH (7.2–7.8) is more alkaline than Yarrow prefers (5.5–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
Heavy clay soil (46% clay) in Somervell County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.
Organic Matter
Organic matter is moderate (3.3%). Annual compost additions will help Yarrow.
How to Plant Yarrow
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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 | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 2.4" | 0" | ❄️ Dormant |
| Mar | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 6.9" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 10.2" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 10.5" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 7.5" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 7.8" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 5.4" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 2.4" | 0" | ✅ Rainfall sufficient |
| Dec | — | 1.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Somervell 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 — Somervell County, TX
Yarrow Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | March 26 | Mar 26 – Apr 9 |
| Harvest | June 25 | Jun 25 – Sep 10 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Transplant Outdoors |
| April | Transplant Outdoors |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 5.5–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 8b
📆 Growing Season
238 days in Somervell County
Growing Tips for Yarrow in Somervell County
Direct sow Yarrow outdoors after March 19 in Somervell County when soil has warmed and frost danger has passed.
With Somervell County's clay soil (46% clay), work in 3-4 inches of compost before planting Yarrow. Avoid tilling when soil is wet to prevent compaction.
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
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
Check more plant combinations with our Companion Planting Checker →
Yarrow in Other Locations
Frequently Asked Questions
When should I plant Yarrow in Somervell County, TX?
Somervell County is in Zone 8b with an average last frost of March 19. Plan your Yarrow planting based on this frost date — see the calendar above for exact timing.
What planting zone is Somervell County, TX?
Somervell County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 19 and first fall frost is November 12.
Your Somervell County Garden Planner — Free
A 24-page printable planner built for Somervell County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.