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When to Plant Komatsuna in Forest County, PA

Forest County, Pennsylvania Zone 6a May

What to do in May

We've pulled the most time-sensitive tasks for Forest County, Pennsylvania this May and put them front and centre. Tackle them in order.

Avg. last frost May 13
Avg. first frost October 13
Soil temp (4") 59°F
Watering Moderate
Pest pressure Low
Daylight 14.3 hrs
  1. Plant out komatsuna

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

Looking ahead to June
  • Starting indoors: komatsuna
  • First harvests: komatsuna

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Komatsuna (Japanese mustard spinach) is a versatile Asian green with glossy, dark leaves and a mild, sweet flavor. It is extremely cold-hardy and heat-tolerant.

Forest County, Pennsylvania is in USDA Zone 6a. The average last spring frost is May 13 and the first fall frost is October 13, giving you a growing season of approximately 153 days.

At an elevation of 125 feet, Forest County receives approximately 40.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Komatsuna to ensure they mature before fall.

Forest County, PA (Zone 6a) Moderate season
153 days
Last Spring Frost May 13
153 growing days
First Fall Frost October 13

Forest County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (85 days to spare)
Start indoors: Mar 31 Transplant: May 5 🍅 Harvest: Jun 9 – Jul 14
Recommended (50%) ✓ Fits season (83 days to spare)
Start indoors: Apr 8 Transplant: May 13 🍅 Harvest: Jun 17 – Jul 22
Safe Start (90%) ✓ Fits season (78 days to spare)
Start indoors: Apr 27 Transplant: Jun 1 🍅 Harvest: Jul 6 – Aug 10

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 Forest County

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

Soil pH

Your soil pH (5.2–6.8) overlaps with Komatsuna's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.9%). Annual compost additions will help Komatsuna.

How to Plant Komatsuna

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 Komatsuna

5
successive plantings in your 153-day season

Sow every 4 weeks. Last sowing by Aug 24 to harvest before frost.

For a dedicated fall crop, sow by Aug 04.

Plant Water Budget

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

Monthly Watering Guide for Komatsuna

Komatsuna needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Komatsuna Needs Rainfall You Supplement Action
Jan 3.1" 0" ❄️ Dormant
Feb 2.8" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 3.3" 0" ❄️ Dormant
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 4.2" 0.1" 💧 Light watering
Jul 4.3" 3.7" 0.6" 💧 Light watering
Aug 4.3" 4" 0.3" 💧 Light watering
Sep 4.3" 3.6" 0.7" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 3.4" 0" ❄️ Dormant
Dec 3.3" 0" ❄️ Dormant

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

Komatsuna 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.

Komatsuna needs ~521 GDD — county provides 1,874 GDD Excellent fit

Komatsuna Planting Timeline — Forest County, PA

Komatsuna Planting Calendar

Activity When Date Range
Start Indoors April 8 Apr 8 – Apr 22
Transplant Outdoors May 13 May 13 – May 27
Direct Sow April 29 Apr 29 – May 20
Harvest June 17 Jun 17 – Jul 22
Fall Sowing August 4 Aug 4 – Aug 18

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

153 days in Forest County

Growing Tips for Komatsuna in Forest County

Direct sow Komatsuna outdoors after May 13 in Forest County when soil has warmed and frost danger has passed.

Your generous 153.0-day season in Forest County allows multiple plantings of Komatsuna. Sow every 17.0 days for continuous harvest.

Common pests for Komatsuna 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 spring or fall. One of the most forgiving Asian greens for all seasons. Harvest outer leaves or cut whole plants. Excellent for stir-fries, soups, or salads.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Komatsuna in Forest County, PA?

Forest County is in Zone 6a with an average last frost of May 13. Plan your Komatsuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Forest County, PA?

Forest County, Pennsylvania is in USDA Hardiness Zone 6a. The average last spring frost is May 13 and first fall frost is October 13.

🌱

Your Forest County Garden Planner — Free

A 24-page printable planner built for Forest County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Forest 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.