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When to Plant Chard in Coos County, OR

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.

Coos County, Oregon is in USDA Zone 8b. The average last spring frost is March 22 and the first fall frost is November 19, giving you a growing season of approximately 242 days.

At an elevation of 96 feet, Coos County receives approximately 38.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Chard during the growing season.

Coos County, OR (Zone 8b) Long season
242 days
Last Spring Frost March 22
242 growing days
First Fall Frost November 19

Coos County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (134 days to spare)
Start indoors: Jan 31 Transplant: Mar 7 🍅 Harvest: May 2 – Jun 20
Recommended (50%) ✓ Fits season (137 days to spare)
Start indoors: Feb 15 Transplant: Mar 22 🍅 Harvest: May 17 – Jul 5
Safe Start (90%) ✓ Fits season (132 days to spare)
Start indoors: Mar 18 Transplant: Apr 22 🍅 Harvest: Jun 17 – Aug 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 Coos County

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

Soil pH

Your soil pH (5.4โ€“6.8) overlaps with Chard's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Coos County is excellent for Chard โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.7%) โ€” Chard will thrive.

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

5
successive plantings in your 242-day season

Sow every 5.7 weeks. Last sowing by Sep 20 to harvest before frost.

For a dedicated fall crop, sow by Sep 10.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.7″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 273 gal / 100 sq ft

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€” 5.5" 0" โ„๏ธ Dormant
Feb โ€” 4.5" 0" โ„๏ธ Dormant
Mar 3.5" 4.4" 0" โœ… Rainfall sufficient
Apr 3.5" 3.1" 0.4" ๐Ÿ’ง Light watering
May 3.5" 2.3" 1.2" ๐Ÿ’ง Light watering
Jun 3.5" 1.6" 1.9" ๐Ÿšฟ Regular watering
Jul 3.5" 0.6" 2.9" ๐Ÿšฟ Regular watering
Aug 3.5" 0.8" 2.7" ๐Ÿšฟ Regular watering
Sep 3.5" 1.4" 2.1" ๐Ÿšฟ Regular watering
Oct 3.5" 3.3" 0.2" ๐Ÿ’ง Light watering
Nov 3.5" 5.9" 0" โœ… Rainfall sufficient
Dec โ€” 5.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Coos 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 ~921 GDD — county provides 4,053 GDD Excellent fit

Chard Planting Timeline โ€” Coos County, OR

Chard Planting Calendar

Activity When Date Range
Start Indoors February 15 Feb 15 โ€“ Mar 1
Transplant Outdoors March 22 Mar 22 โ€“ Apr 5
Direct Sow March 8 Mar 8 โ€“ Mar 29
Harvest May 17 May 17 โ€“ Jul 5
Fall Sowing September 10 Sep 10 โ€“ Sep 24

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

0.8"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

50โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 8b

๐Ÿ“† Growing Season

242 days in Coos County

Growing Tips for Chard in Coos County

Direct sow Chard outdoors after March 22 in Coos County when soil has warmed and frost danger has passed.

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 Coos County, OR?

Coos County is in Zone 8b with an average last frost of March 22. Plan your Chard planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Coos County, OR?

Coos County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is March 22 and first fall frost is November 19.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Coos County gardeners in Zone 8b 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 Coos County, OR. Local conditions may vary. Last updated: April 2026.