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When to Plant Turnip in Allegheny County, PA

Allegheny County, Pennsylvania Zone 6b May

Top priorities for Allegheny County, Pennsylvania gardeners in May

Each item below is timed to Allegheny County, Pennsylvania's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 25
Avg. first frost October 28
Soil temp (4") 62°F
Watering Moderate
Pest pressure Low
Daylight 14.2 hrs
  1. Start harvesting turnip

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

Looking ahead to June
  • First harvests: turnip

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Turnips are a fast-growing cool-season root vegetable with edible roots and greens. Baby turnips are sweet and tender while mature ones are more pungent.

Allegheny County, Pennsylvania is in USDA Zone 6b. The average last spring frost is April 25 and the first fall frost is October 28, giving you a growing season of approximately 186 days.

At an elevation of 118 feet, Allegheny County receives approximately 40.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Turnip during the growing season.

Allegheny County, PA (Zone 6b) Moderate season
186 days
Last Spring Frost April 25
186 growing days
First Fall Frost October 28

Allegheny County Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (105 days to spare)
Transplant: Apr 19 🍅 Harvest: May 31 – Jul 5
Recommended (50%) ✓ Fits season (109 days to spare)
Transplant: Apr 25 🍅 Harvest: Jun 6 – Jul 11
Safe Start (90%) ✓ Fits season (100 days to spare)
Transplant: May 14 🍅 Harvest: Jun 25 – Jul 30

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 Allegheny County

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

Soil pH

Your soil pH (5.0–6.5) is more acidic than Turnip prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Turnip.

How to Plant Turnip

0.5"
Planting Depth
4"
Between Plants
12"
Between Rows

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

Succession Planting Turnip

5
successive plantings in your 186-day season

Sow every 4.6 weeks. Last sowing by Aug 29 to harvest before frost.

For a dedicated fall crop, sow by Aug 19.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 145 gal / 100 sq ft

Monthly Watering Guide for Turnip

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

Month Turnip Needs Rainfall You Supplement Action
Jan 3" 0" ❄️ Dormant
Feb 3.1" 0" ❄️ Dormant
Mar 3.7" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 3.4" 0.9" 💧 Light watering
Jun 4.3" 3.5" 0.8" 💧 Light watering
Jul 4.3" 4.1" 0.2" 💧 Light watering
Aug 4.3" 3.6" 0.7" 💧 Light watering
Sep 4.3" 3" 1.3" 💧 Light watering
Oct 4.3" 3.8" 0.5" 💧 Light watering
Nov 2.9" 0" ❄️ Dormant
Dec 3" 0" ❄️ Dormant

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

Turnip 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.

Turnip needs ~838 GDD — county provides 3,115 GDD Excellent fit

Turnip Planting Timeline — Allegheny County, PA

Turnip Planting Calendar

Activity When Date Range
Direct Sow April 11 Apr 11 – May 2
Harvest May 23 May 23 – Jun 27
Fall Sowing August 19 Aug 19 – Sep 2

Plant 0.5" deep · 4" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

186 days in Allegheny County

Growing Tips for Turnip in Allegheny County

Direct sow Turnip outdoors after April 25 in Allegheny County when soil has warmed and frost danger has passed.

Your generous 186.0-day season in Allegheny County allows multiple plantings of Turnip. Sow every 20.0 days for continuous harvest.

Common pests for Turnip 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 late summer. Harvest when roots are 2-3 inches in diameter for best flavor. Both the roots and the greens are nutritious and edible.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Turnip in Allegheny County, PA?

Allegheny County is in Zone 6b with an average last frost of April 25. Plan your Turnip planting based on this frost date — see the calendar above for exact timing.

What planting zone is Allegheny County, PA?

Allegheny County, Pennsylvania is in USDA Hardiness Zone 6b. The average last spring frost is April 25 and first fall frost is October 28.

🌱

Your Allegheny County Garden Planner — Free

A 24-page printable planner built for Allegheny 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.

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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 Allegheny 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.