When to Plant Yarrow in Navajo County, AZ
May in the garden — Navajo County, Arizona
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
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Plant out yarrow
Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.
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.
Navajo County, Arizona is in USDA Zone 7a. The average last spring frost is May 2 and the first fall frost is October 16, giving you a growing season of approximately 167 days.
At an elevation of 5,528 feet, Navajo County receives approximately 15.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 94°F, providing good warmth for Yarrow during the growing season. 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.
Navajo County Soil Profile
Soil Type
Sandy Loam
Soil pH
7.3-8.3
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 Navajo County
How your county's soil matches Yarrow's growing requirements.
Soil pH
Your soil pH (7.3–8.3) is more alkaline than Yarrow prefers (5.5–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
Sandy soil in Navajo County warms quickly in spring but drains fast. Yarrow will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Yarrow.
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 | — | 1" | 0" | ❄️ Dormant |
| Mar | — | 0.9" | 0" | ❄️ Dormant |
| Apr | — | 0.6" | 0" | ❄️ Dormant |
| May | 2.2" | 0.3" | 1.9" | 🚿 Regular watering |
| Jun | 2.2" | 0.6" | 1.6" | 🚿 Regular watering |
| Jul | 2.2" | 2.4" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.5" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2" | 0.2" | 💧 Light watering |
| Oct | 2.2" | 1.3" | 0.9" | 💧 Light watering |
| Nov | — | 0.8" | 0" | ❄️ Dormant |
| Dec | — | 1.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Navajo 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 — Navajo County, AZ
Yarrow Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 9 | May 9 – May 23 |
| Harvest | August 8 | Aug 8 – Oct 24 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | — |
| July | — |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| 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 7a
📆 Growing Season
167 days in Navajo County
Growing Tips for Yarrow in Navajo County
Direct sow Yarrow outdoors after May 02 in Navajo County when soil has warmed and frost danger has passed.
Sandy soil in Navajo County dries quickly — mulch Yarrow with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
Common pests for Yarrow in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
Navajo County receives only 16" 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 Navajo County, AZ?
Navajo County is in Zone 7a with an average last frost of May 2. Plan your Yarrow planting based on this frost date — see the calendar above for exact timing.
What planting zone is Navajo County, AZ?
Navajo County, Arizona is in USDA Hardiness Zone 7a. The average last spring frost is May 2 and first fall frost is October 16.
Your Navajo County Garden Planner — Free
A 24-page printable planner built for Navajo County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.