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When to Plant Microgreens in Coconino County, AZ

Coconino County, Arizona Zone 7a May

This month in Coconino County, Arizona

A quick May briefing for Coconino County, Arizona gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 28
Avg. first frost September 27
Soil temp (4") 37°F
Watering Critical
Pest pressure Low
Daylight 13.9 hrs
  1. Plant out microgreens

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

  2. Plant microgreens from seed, right in the garden

    Mark the row. Birds and stray feet both have opinions about unmarked beds.

June prep starts now
  • First harvests: microgreens

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Microgreens are young seedlings of vegetables and herbs harvested at the cotyledon or first true leaf stage. They pack concentrated flavors and nutrients in a tiny package.

Coconino County, Arizona is in USDA Zone 7a. The average last spring frost is May 28 and the first fall frost is September 27, giving you a growing season of approximately 122 days.

At an elevation of 7,869 feet, Coconino County receives approximately 13.9 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Microgreens may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Microgreens will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Microgreens successfully. Mulch heavily to conserve soil moisture.

Coconino County, AZ (Zone 7a) Short season
122 days
Last Spring Frost May 28
122 growing days
First Fall Frost September 27

Coconino County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (116 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: Apr 24 – May 22
Recommended (50%) ✓ Fits season (87 days to spare)
Start indoors: Apr 23 Transplant: May 28 🍅 Harvest: Jun 4 – Jul 2
Safe Start (90%) ✓ Fits season (99 days to spare)
Start indoors: May 20 Transplant: Jun 24 🍅 Harvest: Jul 1 – Jul 29

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 Coconino County

How your county's soil matches Microgreens's growing requirements.

Soil pH

Your soil pH (7.2–8.6) is more alkaline than Microgreens prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Microgreens.

Organic Matter

Organic matter is low (0.8%). Add 2-3 inches of compost before planting Microgreens.

How to Plant Microgreens

0.5"
Planting Depth
2"
Between Plants
6"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Microgreens

24
successive plantings in your 122-day season

Sow every 0.7 weeks. Last sowing by Sep 06 to harvest before frost.

For a dedicated fall crop, sow by Jul 19.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 1,070 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Microgreens

Microgreens needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Microgreens Needs Rainfall You Supplement Action
Jan 1" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 0.8" 0" ❄️ Dormant
Apr 0.4" 0" ❄️ Dormant
May 4.3" 0.3" 4" 🚿 Regular watering
Jun 4.3" 0.4" 3.9" 🚿 Regular watering
Jul 4.3" 2.6" 1.7" 💧 Light watering
Aug 4.3" 3" 1.3" 💧 Light watering
Sep 4.3" 1.7" 2.6" 🚿 Regular watering
Oct 1.3" 0" ❄️ Dormant
Nov 0.8" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Coconino County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Microgreens 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.

Microgreens needs ~308 GDD — county provides 2,684 GDD Excellent fit

Microgreens Planting Timeline — Coconino County, AZ

Microgreens Planting Calendar

Activity When Date Range
Start Indoors April 23 Apr 23 – May 7
Transplant Outdoors May 28 May 28 – Jun 11
Direct Sow May 14 May 14 – Jun 4
Harvest June 4 Jun 4 – Jul 2
Fall Sowing July 19 Jul 19 – Aug 2

Plant 0.5" deep · 2" apart · Rows 6" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Start Indoors Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow Harvest
July Fall Sowing Harvest
August Fall Sowing
September
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

7–21 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

122 days in Coconino County

Growing Tips for Microgreens in Coconino County

Direct sow Microgreens outdoors after May 28 in Coconino County when soil has warmed and frost danger has passed.

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

With summer highs reaching 96°F in Coconino County, provide afternoon shade for Microgreens and water deeply in the morning.

Your generous 122.0-day season in Coconino County allows multiple plantings of Microgreens. Sow every 3.0 days for continuous harvest.

Coconino County receives only 14" of rain annually. Microgreens needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Sow seeds densely on shallow trays of moist growing medium. Cover until germination, then provide light. Harvest with scissors when 1-3 inches tall. Grow year-round indoors.

Frequently Asked Questions

When should I plant Microgreens in Coconino County, AZ?

Coconino County is in Zone 7a with an average last frost of May 28. Plan your Microgreens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Coconino County, AZ?

Coconino County, Arizona is in USDA Hardiness Zone 7a. The average last spring frost is May 28 and first fall frost is September 27.

🌱

Your Coconino County Garden Planner — Free

A 24-page printable planner built for Coconino 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.

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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 Coconino County, AZ. Local conditions may vary. Last updated: May 2026.

Sources & credits

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