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When to Plant Rue in Navajo County, AZ

Navajo County, Arizona Zone 6a April

April in the garden — Navajo County, Arizona

Your Navajo County, Arizona garden is entering a new phase. Here's what's on the schedule for April and why each task matters now.

Avg. last frost May 2
Avg. first frost October 16
Soil temp (4") 36°F
Watering Critical
Pest pressure Low
Daylight 12.9 hrs
May will be here before you know it — start on
  • Transplants going out: rue

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Rue is a bitter, aromatic perennial herb with bluish-green foliage used historically in medicine and as a pest deterrent. Handle with care as its sap can cause skin irritation.

Navajo County, Arizona is in USDA Zone 6a. 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 Rue during the growing season. Sandy soil warms quickly in spring — great for early planting — but Rue will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Rue successfully. Mulch heavily to conserve soil moisture.

Navajo County, AZ (Zone 6a) Moderate season
167 days
Last Spring Frost May 2
167 growing days
First Fall Frost October 16
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Navajo County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.3-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (28 days to spare)
Transplant: May 2 🍅 Harvest: Jul 11 – Sep 12
Recommended (50%) ✓ Fits season (27 days to spare)
Transplant: May 9 🍅 Harvest: Jul 18 – Sep 19
Safe Start (90%) ✓ Fits season (26 days to spare)
Transplant: May 25 🍅 Harvest: Aug 3 – Oct 5

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 Rue's growing requirements.

Soil pH

Your soil pH (7.3–8.3) is more alkaline than Rue prefers (6.0–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Navajo County warms quickly in spring but drains fast. Rue will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Rue.

Organic Matter

Organic matter is low (0.7%). Add 2-3 inches of compost before planting Rue.

How to Plant Rue

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Rue

2
successive plantings in your 167-day season

Sow every 8 weeks. Last sowing by Jul 18 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.4″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 451 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Rue

Rue 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 Rue 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.

Rue 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.

Rue needs ~1,640 GDD — county provides 3,423 GDD Excellent fit

Rue Planting Timeline — Navajo County, AZ

Rue Planting Calendar

Activity When Date Range
Transplant Outdoors May 9 May 9 – May 23
Harvest July 18 Jul 18 – Sep 19

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June
July Harvest
August Harvest
September Harvest
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · 1-2 times/week

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

167 days in Navajo County

Growing Tips for Rue in Navajo County

Direct sow Rue outdoors after May 02 in Navajo County when soil has warmed and frost danger has passed.

Sandy soil in Navajo County dries quickly — mulch Rue with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Navajo County receives only 16" of rain annually. Rue needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors or direct sow. Plant in well-drained soil. Wear gloves when handling as sap can cause phytophotodermatitis. Prune in early spring.

Companion Planting

Good Companions

Avoid Planting Near

  • Basil
  • Sage

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Rue in Navajo County, AZ?

Navajo County is in Zone 6a with an average last frost of May 2. Plan your Rue 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 6a. 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 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Navajo County, AZ. Local conditions may vary. Last updated: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.