Blog

When to Plant Mustard Greens in Chester County, PA

Chester County, Pennsylvania Zone 7a May

Your May planting checklist for Chester County, Pennsylvania

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

Avg. last frost April 16
Avg. first frost October 27
Soil temp (4") 62°F
Watering Moderate
Pest pressure Low
Daylight 14.2 hrs
  1. Start mustard greens indoors

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

  2. Start harvesting mustard greens

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

To set up a strong June, finish these tasks
  • First harvests: mustard greens

Instant PDF download. No spam, unsubscribe any time.

Mustard greens are fast-growing brassicas with a spicy, peppery kick. They come in green, red, and purple varieties and are excellent cooked or in salads.

Chester County, Pennsylvania is in USDA Zone 7a. The average last spring frost is April 16 and the first fall frost is October 27, giving you a growing season of approximately 194 days.

At an elevation of 761 feet, Chester County receives approximately 42.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Mustard Greens during the growing season.

Chester County, PA (Zone 7a) Moderate season
194 days
Last Spring Frost April 16
194 growing days
First Fall Frost October 27

Chester County Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (93 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: May 15 – Jul 17
Recommended (50%) ✓ Fits season (96 days to spare)
Start indoors: Mar 12 Transplant: Apr 16 🍅 Harvest: May 21 – Jul 23
Safe Start (90%) ✓ Fits season (85 days to spare)
Start indoors: Mar 31 Transplant: May 5 🍅 Harvest: Jun 9 – Aug 11

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 Chester County

How your county's soil matches Mustard Greens's growing requirements.

Soil pH

Your soil pH (4.9–6.6) is more acidic than Mustard Greens prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.1%). Annual compost additions will help Mustard Greens.

How to Plant Mustard Greens

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

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

Succession Planting Mustard Greens

7
successive plantings in your 194-day season

Sow every 3.4 weeks. Last sowing by Sep 07 to harvest before frost.

For a dedicated fall crop, sow by Aug 18.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Mustard Greens

Mustard Greens needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Mustard Greens Needs Rainfall You Supplement Action
Jan 3" 0" ❄️ Dormant
Feb 2.8" 0" ❄️ Dormant
Mar 3.7" 0" ❄️ Dormant
Apr 3" 3.8" 0" ✅ Rainfall sufficient
May 3" 3.5" 0" ✅ Rainfall sufficient
Jun 3" 4.1" 0" ✅ Rainfall sufficient
Jul 3" 4.4" 0" ✅ Rainfall sufficient
Aug 3" 3.5" 0" ✅ Rainfall sufficient
Sep 3" 3.6" 0" ✅ Rainfall sufficient
Oct 3" 3.9" 0" ✅ Rainfall sufficient
Nov 3.4" 0" ❄️ Dormant
Dec 3" 0" ❄️ Dormant

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

Mustard Greens 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.

Mustard Greens needs ~580 GDD — county provides 2,813 GDD Excellent fit

Mustard Greens Planting Timeline — Chester County, PA

Mustard Greens Planting Calendar

Activity When Date Range
Start Indoors March 12 Mar 12 – Mar 26
Transplant Outdoors April 16 Apr 16 – Apr 30
Direct Sow April 2 Apr 2 – Apr 23
Harvest May 21 May 21 – Jul 23
Fall Sowing August 18 Aug 18 – Sep 1

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

30–50 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7a

📆 Growing Season

194 days in Chester County

Growing Tips for Mustard Greens in Chester County

Direct sow Mustard Greens outdoors after April 16 in Chester County when soil has warmed and frost danger has passed.

Your generous 194.0-day season in Chester County allows multiple plantings of Mustard Greens. Sow every 15.0 days for continuous harvest.

Common pests for Mustard Greens in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow in early spring or fall. Harvest young leaves for milder flavor. Plants bolt quickly in heat so grow as a cool-season crop or provide shade.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mustard Greens in Chester County, PA?

Chester County is in Zone 7a with an average last frost of April 16. Plan your Mustard Greens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Chester County, PA?

Chester County, Pennsylvania is in USDA Hardiness Zone 7a. The average last spring frost is April 16 and first fall frost is October 27.

🌱

Your Chester County Garden Planner — Free

A 24-page printable planner built for Chester 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.

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 Chester County, PA. 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.