Blog

When to Plant Ground Cherry in Washington County, TN

Washington County, Tennessee Zone 7b May

May in the garden — Washington County, Tennessee

Welcome to May in Zone 7b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 15
Avg. first frost October 22
Soil temp (4") 55°F
Watering Moderate
Pest pressure Low
Daylight 13.9 hrs
  1. Move ground cherry from tray to bed

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

Instant PDF download. No spam, unsubscribe any time.

Ground cherries produce small, sweet, tropical-tasting berries enclosed in papery husks. They are related to tomatillos and cape gooseberries and self-sow readily.

Washington County, Tennessee is in USDA Zone 7b. The average last spring frost is April 15 and the first fall frost is October 22, giving you a growing season of approximately 190 days.

At an elevation of 2,969 feet, Washington County receives approximately 41.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Ground Cherry during the growing season.

Washington County, TN (Zone 7b) Moderate season
190 days
Last Spring Frost April 15
190 growing days
First Fall Frost October 22
Share this guide:

Washington County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (45 days to spare)
Transplant: Apr 30 🍅 Harvest: Jul 9 – Sep 3
Recommended (50%) ✓ Fits season (43 days to spare)
Transplant: May 6 🍅 Harvest: Jul 15 – Sep 9
Safe Start (90%) ✓ Fits season (38 days to spare)
Transplant: May 23 🍅 Harvest: Aug 1 – Sep 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 Washington County

How your county's soil matches Ground Cherry's growing requirements.

Soil pH

Your soil pH (5.5–7.1) overlaps with Ground Cherry's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Ground Cherry.

How to Plant Ground Cherry

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Succession Planting Ground Cherry

3
successive plantings in your 190-day season

Sow every 7.4 weeks. Last sowing by Aug 03 to harvest before frost.

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 147 gal / 100 sq ft

Monthly Watering Guide for Ground Cherry

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

Month Ground Cherry Needs Rainfall You Supplement Action
Jan 3.4" 0" ❄️ Dormant
Feb 3.6" 0" ❄️ Dormant
Mar 3.8" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 2.8" 1.5" 💧 Light watering
Jun 4.3" 3.4" 0.9" 💧 Light watering
Jul 4.3" 4.3" 0" ✅ Rainfall sufficient
Aug 4.3" 3.6" 0.7" 💧 Light watering
Sep 4.3" 3.4" 0.9" 💧 Light watering
Oct 4.3" 2.9" 1.4" 💧 Light watering
Nov 3.5" 0" ❄️ Dormant
Dec 3.4" 0" ❄️ Dormant

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

Ground Cherry 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.

Ground Cherry needs ~1,214 GDD — county provides 3,182 GDD Excellent fit

Ground Cherry Planting Timeline — Washington County, TN

Ground Cherry Planting Calendar

Activity When Date Range
Transplant Outdoors May 6 May 6 – May 20
Harvest July 15 Jul 15 – Sep 9

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June
July Harvest
August Harvest
September Harvest
October
November
December
Share this guide:

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

65–80 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

190 days in Washington County

Growing Tips for Ground Cherry in Washington County

Direct sow Ground Cherry outdoors after April 15 in Washington County when soil has warmed and frost danger has passed.

Common pests for Ground Cherry 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. Let fruits fall to the ground naturally when ripe inside their husks. The husk turns brown and papery when the fruit is ready.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Ground Cherry in Washington County, TN?

Washington County is in Zone 7b with an average last frost of April 15. Plan your Ground Cherry planting based on this frost date — see the calendar above for exact timing.

What planting zone is Washington County, TN?

Washington County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 15 and first fall frost is October 22.

🌱

Your Washington County Garden Planner — Free

A 24-page printable planner built for Washington County (Zone 7b). 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 Washington County, TN. 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.