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When to Plant Chard in Mercer County, WV

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.

Mercer County, West Virginia is in USDA Zone 6b. The average last spring frost is May 7 and the first fall frost is October 10, giving you a growing season of approximately 156 days.

At an elevation of 1,135 feet, Mercer County receives approximately 42.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Chard during the growing season.

Mercer County, WV (Zone 6b) Moderate season
156 days
Last Spring Frost May 7
156 growing days
First Fall Frost October 10

Mercer County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (48 days to spare)
Start indoors: Mar 27 Transplant: May 1 🍅 Harvest: Jun 26 – Aug 14
Recommended (50%) ✓ Fits season (51 days to spare)
Start indoors: Apr 2 Transplant: May 7 🍅 Harvest: Jul 2 – Aug 20
Safe Start (90%) ✓ Fits season (49 days to spare)
Start indoors: Apr 17 Transplant: May 22 🍅 Harvest: Jul 17 – Sep 4

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 Mercer County

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

Soil pH

Your soil pH (5.5โ€“6.9) overlaps with Chard's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.3%). Annual compost additions will help 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

3
successive plantings in your 156-day season

Sow every 5.7 weeks. Last sowing by Aug 11 to harvest before frost.

For a dedicated fall crop, sow by Aug 01.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 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€” 3.6" 0" โ„๏ธ Dormant
Feb โ€” 3.8" 0" โ„๏ธ Dormant
Mar โ€” 4.5" 0" โ„๏ธ Dormant
Apr โ€” 3" 0" โ„๏ธ Dormant
May 3.5" 3" 0.5" ๐Ÿ’ง Light watering
Jun 3.5" 4.3" 0" โœ… Rainfall sufficient
Jul 3.5" 3.9" 0" โœ… Rainfall sufficient
Aug 3.5" 3.9" 0" โœ… Rainfall sufficient
Sep 3.5" 3" 0.5" ๐Ÿ’ง Light watering
Oct 3.5" 2.6" 0.9" ๐Ÿ’ง Light watering
Nov โ€” 3.2" 0" โ„๏ธ Dormant
Dec โ€” 3.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Mercer 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 ~756 GDD — county provides 2,145 GDD Excellent fit

Chard Planting Timeline โ€” Mercer County, WV

Chard Planting Calendar

Activity When Date Range
Start Indoors April 2 Apr 2 โ€“ Apr 16
Transplant Outdoors May 7 May 7 โ€“ May 21
Direct Sow April 23 Apr 23 โ€“ May 14
Harvest July 2 Jul 2 โ€“ Aug 20
Fall Sowing August 1 Aug 1 โ€“ Aug 15

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

0.8"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

50โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

156 days in Mercer County

Growing Tips for Chard in Mercer County

Direct sow Chard outdoors after May 07 in Mercer 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 Mercer County, WV?

Mercer County is in Zone 6b with an average last frost of May 7. Plan your Chard planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Mercer County, WV?

Mercer County, West Virginia is in USDA Hardiness Zone 6b. The average last spring frost is May 7 and first fall frost is October 10.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Mercer County gardeners in Zone 6b 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 Mercer County, WV. Local conditions may vary. Last updated: April 2026.