When to Plant Yarrow in La Paz County, AZ
Top priorities for La Paz County, Arizona gardeners in May
Welcome to May in Zone 9a. These are the moves that will have the biggest impact on your growing season.
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Basket week: yarrow
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
A few tasks this May that'll pay off in June
- 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.
La Paz County, Arizona is in USDA Zone 9a. The average last spring frost is February 2 and the first fall frost is December 6, giving you a growing season of approximately 307 days.
At an elevation of 4,875 feet, La Paz County receives approximately 17.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 105°F, so Yarrow may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Yarrow will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Yarrow successfully. Mulch heavily to conserve soil moisture.
La Paz County Soil Profile
Soil Type
Sandy Loam
Soil pH
7.2-8.3
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 La Paz County
How your county's soil matches Yarrow's growing requirements.
Soil pH
Your soil pH (7.2–8.3) is more alkaline than Yarrow prefers (5.5–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
Sandy soil in La Paz County warms quickly in spring but drains fast. Yarrow will need more frequent watering and regular compost additions to retain nutrients.
Organic Matter
Organic matter is low (0.7%). Add 2-3 inches of compost before planting Yarrow.
How to Plant Yarrow
Plant Water Budget
Water stress score is 10/10 — 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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | 2.2" | 0.9" | 1.3" | 🚿 Regular watering |
| Mar | 2.2" | 1" | 1.2" | 🚿 Regular watering |
| Apr | 2.2" | 0.6" | 1.6" | 🚿 Regular watering |
| May | 2.2" | 0.4" | 1.8" | 🚿 Regular watering |
| Jun | 2.2" | 0.7" | 1.5" | 🚿 Regular watering |
| Jul | 2.2" | 2.5" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2.5" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 1.6" | 0.6" | 💧 Light watering |
| Nov | 2.2" | 1" | 1.2" | 🚿 Regular watering |
| Dec | 2.2" | 1.2" | 1" | 💧 Light watering |
Water needs are for active growing months only (Feb–Dec in La Paz 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 — La Paz County, AZ
Yarrow Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | February 9 | Feb 9 – Feb 23 |
| Harvest | May 11 | May 11 – Jul 27 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Transplant Outdoors |
| March | — |
| April | — |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · 1-2 times/week
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 5.5–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 9a
📆 Growing Season
307 days in La Paz County
Growing Tips for Yarrow in La Paz County
Direct sow Yarrow outdoors after February 02 in La Paz County when soil has warmed and frost danger has passed.
Sandy soil in La Paz County dries quickly — mulch Yarrow with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
With summer highs reaching 105°F in La Paz County, provide afternoon shade for Yarrow and water deeply in the morning.
Common pests for Yarrow in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
La Paz County receives only 17" of rain annually. Yarrow needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
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 La Paz County, AZ?
La Paz County is in Zone 9a with an average last frost of February 2. Plan your Yarrow planting based on this frost date — see the calendar above for exact timing.
What planting zone is La Paz County, AZ?
La Paz County, Arizona is in USDA Hardiness Zone 9a. The average last spring frost is February 2 and first fall frost is December 6.
Your La Paz County Garden Planner — Free
A 24-page printable planner built for La Paz County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.