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When to Plant Tomatoes in Warren County, PA

Warren County, Pennsylvania Zone 6a May

May in the garden — Warren County, Pennsylvania

Your Warren 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 May 13
Avg. first frost October 13
Soil temp (4") 58°F
Watering Low
Pest pressure Low
Daylight 14.4 hrs
  1. Set out tomatoes seedlings

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

  2. Scatter tomatoes into prepared beds

    Mark the row. Birds and stray feet both have opinions about unmarked beds.

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Tomatoes are the most popular home garden crop, available in thousands of varieties from tiny cherries to massive beefsteaks. They are warm-season plants needing full sun.

Warren 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 1,158 feet, Warren County receives approximately 43.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Tomatoes to ensure they mature before fall.

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

Warren County Soil Profile

Soil Type

Silt Loam

Soil pH

5.1-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (8 days to spare)
Start indoors: Mar 10 Transplant: May 19 🍅 Harvest: Jul 21 – Sep 29
Recommended (50%) ✓ Fits season (6 days to spare)
Start indoors: Mar 18 Transplant: May 27 🍅 Harvest: Jul 29 – Oct 7
Safe Start (90%) ✓ Fits season (1 days to spare)
Start indoors: Apr 6 Transplant: Jun 15 🍅 Harvest: Aug 17 – Oct 26

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 Warren County

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

Soil pH

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

Soil Texture

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

Organic Matter

Organic matter is moderate (3.6%). Annual compost additions will help Tomatoes.

How to Plant Tomatoes

0.5"
Planting Depth
24"
Between Plants
36"
Between Rows

Succession Planting Tomatoes

2
successive plantings in your 153-day season

Sow every 6.9 weeks. Last sowing by Jul 20 to harvest before frost.

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
1.2″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 15 gal / 100 sq ft

Monthly Watering Guide for Tomatoes

Tomatoes needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.

Month Tomatoes Needs Rainfall You Supplement Action
Jan 3.3" 0" ❄️ Dormant
Feb 2.8" 0" ❄️ Dormant
Mar 3.6" 0" ❄️ Dormant
Apr 3.4" 0" ❄️ Dormant
May 5.2" 3.9" 1.3" 💧 Light watering
Jun 5.2" 3.6" 1.6" 💧 Light watering
Jul 5.2" 4.5" 0.7" 💧 Light watering
Aug 5.2" 4.1" 1.1" 💧 Light watering
Sep 5.2" 4.1" 1.1" 💧 Light watering
Oct 5.2" 3.5" 1.7" 💧 Light watering
Nov 3.7" 0" ❄️ Dormant
Dec 2.8" 0" ❄️ Dormant

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

Tomatoes 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.

Tomatoes needs ~942 GDD — county provides 1,989 GDD Excellent fit

Tomatoes Planting Timeline — Warren County, PA

Tomatoes Planting Calendar

Activity When Date Range
Start Indoors March 18 Mar 18 – Apr 1
Transplant Outdoors May 27 May 27 – Jun 10
Direct Sow May 20 May 20 – Jun 10
Harvest July 29 Jul 29 – Oct 7

Plant 0.5" deep · 24" apart · Rows 36" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.2"/week · Only during dry spells

📅 Days to Maturity

60–85 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6a

📆 Growing Season

153 days in Warren County

Growing Tips for Tomatoes in Warren County

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

Common pests for Tomatoes in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 6-8 weeks before last frost. Bury transplants deep to encourage rooting along the stem. Provide consistent moisture to prevent blossom end rot and cracking.

Companion Planting

Good Companions

Avoid Planting Near

  • Cabbage
  • Fennel
  • Potatoes

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Tomatoes Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Scoop seeds from ripe fruit; ferment 2-3 days to remove gel coating.
Storage Store airtight; viable 4-6 years at 35°F, under 45% humidity.

Isolate 25 ft between varieties for purity. Use open-pollinated varieties for true-to-type seeds.

Frequently Asked Questions

When should I plant Tomatoes in Warren County, PA?

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

What planting zone is Warren County, PA?

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

🌱

Your Warren County Garden Planner — Free

A 24-page printable planner built for Warren 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 Warren 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.