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When to Plant Chard in Coconino County, AZ

Swiss chard is a colorful, heat-tolerant green with large crinkled leaves and vibrant stalks in red, yellow, and white. Both the leaves and stems are edible and nutritious.

Coconino County, Arizona is in USDA Zone 5b. 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 96ยฐF, so Chard may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Chard will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Chard successfully. Mulch heavily to conserve soil moisture.

Coconino County, AZ (Zone 5b) 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 (46 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: Jun 12 – Jul 31
Recommended (50%) ✓ Fits season (17 days to spare)
Start indoors: Apr 23 Transplant: May 28 🍅 Harvest: Jul 23 – Sep 10
Safe Start (90%) ✓ Fits season (29 days to spare)
Start indoors: May 20 Transplant: Jun 24 🍅 Harvest: Aug 19 – Oct 7

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 Chard's growing requirements.

Soil pH

Your soil pH (7.2โ€“8.6) is more alkaline than Chard prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Chard.

Organic Matter

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

How to Plant Chard

1"
Planting Depth
15"
Between Plants
24"
Between Rows

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

Succession Planting Chard

2
successive plantings in your 122-day season

Sow every 5.7 weeks. Last sowing by Jul 29 to harvest before frost.

For a dedicated fall crop, sow by Jul 19.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.5″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 732 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Chard

Chard needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Chard Needs Rainfall You Supplement Action
Jan โ€” 1" 0" โ„๏ธ Dormant
Feb โ€” 0.7" 0" โ„๏ธ Dormant
Mar โ€” 0.8" 0" โ„๏ธ Dormant
Apr โ€” 0.4" 0" โ„๏ธ Dormant
May 3.5" 0.3" 3.2" ๐Ÿšฟ Regular watering
Jun 3.5" 0.4" 3.1" ๐Ÿšฟ Regular watering
Jul 3.5" 2.6" 0.9" ๐Ÿ’ง Light watering
Aug 3.5" 3" 0.5" ๐Ÿ’ง Light watering
Sep 3.5" 1.7" 1.8" ๐Ÿšฟ Regular watering
Oct โ€” 1.3" 0" โ„๏ธ Dormant
Nov โ€” 0.8" 0" โ„๏ธ Dormant
Dec โ€” 0.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Coconino County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Chard 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" โ€” every day above 50ยฐF 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.

Chard needs ~1,210 GDD — county provides 2,684 GDD Excellent fit

Chard Planting Timeline โ€” Coconino County, AZ

Chard Planting Calendar

Activity When Date Range
Start Indoors April 23 Apr 23 โ€“ May 7
Transplant Outdoors May 28 May 28 โ€“ Jun 11
Direct Sow May 14 May 14 โ€“ Jun 4
Harvest July 23 Jul 23 โ€“ Sep 10
Fall Sowing July 19 Jul 19 โ€“ Aug 2

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

0.8"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

50โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 5b

๐Ÿ“† Growing Season

122 days in Coconino County

Growing Tips for Chard in Coconino County

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

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

Summer highs in Coconino County reach 96ยฐF โ€” grow Chard as a spring or fall crop. Use shade cloth if planting in summer.

General growing tips

Direct sow or transplant after last frost. Harvest outer leaves regularly to encourage continuous production. Chard tolerates both heat and light frost.

Companion Planting

Good Companions

Avoid Planting Near

  • Corn
  • Cucumbers

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Chard in Coconino County, AZ?

Coconino County is in Zone 5b with an average last frost of May 28. Plan your Chard planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Coconino County, AZ?

Coconino County, Arizona is in USDA Hardiness Zone 5b. The average last spring frost is May 28 and first fall frost is September 27.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Coconino County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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: April 2026.