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When to Plant Chard in Union County, PA

Union County, Pennsylvania Zone 6b June

Union County, Pennsylvania gardeners: here's your June plan

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

Avg. last frost April 27
Avg. first frost October 22
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 14.9 hrs
  1. Time to start chard inside

    Label every cell. You will absolutely forget which is which otherwise.

  2. Pick chard

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

July will be here before you know it — start on
  • First harvests: chard

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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.

Union County, Pennsylvania is in USDA Zone 6b. The average last spring frost is April 27 and the first fall frost is October 22, giving you a growing season of approximately 178 days.

At an elevation of 250 feet, Union County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Chard during the growing season.

Union County, PA (Zone 6b) Moderate season
178 days
Last Spring Frost April 27
178 growing days
First Fall Frost October 22

Union County Soil Profile

Soil Type

Silt Loam

Soil pH

5.1-6.2

Drainage

Well Drained

Chard Planting Risk Windows

Early Start (70% safe) ✓ Fits season (72 days to spare)
Start indoors: Mar 19 Transplant: Apr 23 🍅 Harvest: Jun 18 – Aug 6
Recommended (50%) ✓ Fits season (73 days to spare)
Start indoors: Mar 23 Transplant: Apr 27 🍅 Harvest: Jun 22 – Aug 10
Safe Start (90%) ✓ Fits season (66 days to spare)
Start indoors: Apr 10 Transplant: May 15 🍅 Harvest: Jul 10 – Aug 28

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 Union County

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

Soil pH

Your soil pH (5.1–6.2) is more acidic than Chard prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Union County is excellent for Chard — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.7%). 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

4
successive plantings in your 178-day season

Sow every 5.7 weeks. Last sowing by Aug 23 to harvest before frost.

For a dedicated fall crop, sow by Aug 13.

Chard Water Budget

Plant needs
0.8″/week
Rainfall provides
0.9″/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 2.9" 0" ❄️ Dormant
Feb 2.6" 0" ❄️ Dormant
Mar 3.2" 0" ❄️ Dormant
Apr 3.5" 3.5" 0" ✅ Rainfall sufficient
May 3.5" 4" 0" ✅ Rainfall sufficient
Jun 3.5" 3.8" 0" ✅ Rainfall sufficient
Jul 3.5" 4" 0" ✅ Rainfall sufficient
Aug 3.5" 3" 0.5" 💧 Light watering
Sep 3.5" 3.3" 0.2" 💧 Light watering
Oct 3.5" 2.9" 0.6" 💧 Light watering
Nov 2.9" 0" ❄️ Dormant
Dec 2.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Union County). Supplement amounts are based on average rainfall — 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" — 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.

Chard needs ~756 GDD — county provides 2,447 GDD Excellent fit

Chard Planting Timeline — Union County, PA

Chard Planting Calendar

Activity When Date Range
Start Indoors March 23 Mar 23 – Apr 6
Transplant Outdoors April 27 Apr 27 – May 11
Direct Sow April 13 Apr 13 – May 4
Harvest June 22 Jun 22 – Aug 10
Fall Sowing August 13 Aug 13 – Aug 27

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.8"/week · Natural rainfall sufficient

📅 Days to Maturity

50–60 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

178 days in Union County

Growing Tips for Chard in Union County

Direct sow Chard outdoors after April 27 in Union 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 Union County, PA?

Union County is in Zone 6b with an average last frost of April 27. Plan your Chard planting based on this frost date — see the calendar above for exact timing.

What planting zone is Union County, PA?

Union County, Pennsylvania is in USDA Hardiness Zone 6b. The average last spring frost is April 27 and first fall frost is October 22.

🌱

Your Union County Garden Planner — Free

A 22-page printable planner built for Union County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

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