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When to Plant Tarragon in Berks County, PA

Berks County, Pennsylvania Zone 7a May

May in the garden — Berks County, Pennsylvania

Here's what deserves your attention in Berks County, Pennsylvania this month. Everything below is tailored to Zone 7a and timed around your local frost dates.

Avg. last frost April 21
Avg. first frost October 24
Soil temp (4") 65°F
Watering Low
Pest pressure Low
Daylight 14.2 hrs
Before June arrives, get these ready
  • First harvests: tarragon

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French tarragon is a perennial herb with slender leaves and a distinctive anise-like flavor essential in French cooking. It does not produce viable seed and must be propagated vegetatively.

Berks County, Pennsylvania is in USDA Zone 7a. The average last spring frost is April 21 and the first fall frost is October 24, giving you a growing season of approximately 186 days.

At an elevation of 877 feet, Berks County receives approximately 46.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Tarragon during the growing season.

Berks County, PA (Zone 7a) Moderate season
186 days
Last Spring Frost April 21
186 growing days
First Fall Frost October 24
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Berks County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (47 days to spare)
Transplant: Apr 20 🍅 Harvest: Jun 22 – Aug 31
Recommended (50%) ✓ Fits season (46 days to spare)
Transplant: Apr 28 🍅 Harvest: Jun 30 – Sep 8
Safe Start (90%) ✓ Fits season (37 days to spare)
Transplant: May 17 🍅 Harvest: Jul 19 – Sep 27

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 Berks County

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

Soil pH

Your soil pH (4.8–6.2) is more acidic than Tarragon prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.3%). Annual compost additions will help Tarragon.

How to Plant Tarragon

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Tarragon

3
successive plantings in your 186-day season

Sow every 6.9 weeks. Last sowing by Jul 26 to harvest before frost.

Plant Water Budget

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

Monthly Watering Guide for Tarragon

Tarragon needs approximately 0.4 inches of water per week (1.7" per month). Here's how your county's rainfall compares month by month.

Month Tarragon Needs Rainfall You Supplement Action
Jan 2.8" 0" ❄️ Dormant
Feb 3.2" 0" ❄️ Dormant
Mar 4.1" 0" ❄️ Dormant
Apr 1.7" 4.1" 0" ✅ Rainfall sufficient
May 1.7" 4.5" 0" ✅ Rainfall sufficient
Jun 1.7" 4.1" 0" ✅ Rainfall sufficient
Jul 1.7" 4.2" 0" ✅ Rainfall sufficient
Aug 1.7" 4.3" 0" ✅ Rainfall sufficient
Sep 1.7" 4" 0" ✅ Rainfall sufficient
Oct 1.7" 3.8" 0" ✅ Rainfall sufficient
Nov 3.4" 0" ❄️ Dormant
Dec 3.6" 0" ❄️ Dormant

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

Tarragon 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.

Tarragon needs ~1,031 GDD — county provides 2,557 GDD Excellent fit

Tarragon Planting Timeline — Berks County, PA

Tarragon Planting Calendar

Activity When Date Range
Transplant Outdoors April 28 Apr 28 – May 12
Harvest June 30 Jun 30 – Sep 8

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Transplant Outdoors
May Transplant Outdoors
June Harvest
July Harvest
August Harvest
September Harvest
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.4"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7a

📆 Growing Season

186 days in Berks County

Growing Tips for Tarragon in Berks County

Direct sow Tarragon outdoors after April 21 in Berks County when soil has warmed and frost danger has passed.

Common pests for Tarragon in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Purchase plants or divisions as French tarragon does not grow true from seed. Plant in well-drained soil. Divide every 3-4 years to maintain vigor. Harvest tips regularly for best flavor.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Tarragon in Berks County, PA?

Berks County is in Zone 7a with an average last frost of April 21. Plan your Tarragon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Berks County, PA?

Berks County, Pennsylvania is in USDA Hardiness Zone 7a. The average last spring frost is April 21 and first fall frost is October 24.

🌱

Your Berks County Garden Planner — Free

A 24-page printable planner built for Berks 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.

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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 Berks 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.