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When to Plant Ground Cherry in Columbia County, WA

Columbia County, Washington Zone 7a May

May in Columbia County, Washington — your action list

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 28
Avg. first frost October 11
Soil temp (4") 56°F
Watering High
Pest pressure Low
Daylight 14.8 hrs
  1. Get ground cherry in the ground

    Your last frost (April 28) has passed. These warm-season crops can handle outdoor soil now.

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

Columbia County, Washington is in USDA Zone 7a. The average last spring frost is April 28 and the first fall frost is October 11, giving you a growing season of approximately 166 days.

At an elevation of 3,157 feet, Columbia County receives approximately 21.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Ground Cherry during the growing season.

Columbia County, WA (Zone 7a) Moderate season
166 days
Last Spring Frost April 28
166 growing days
First Fall Frost October 11
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Columbia County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (20 days to spare)
Transplant: May 9 🍅 Harvest: Jul 18 – Sep 12
Recommended (50%) ✓ Fits season (19 days to spare)
Transplant: May 19 🍅 Harvest: Jul 28 – Sep 22
Safe Start (90%) ✓ Fits season (15 days to spare)
Transplant: Jun 8 🍅 Harvest: Aug 17 – Oct 12

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 Columbia County

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

Soil pH

Your soil pH (5.5–6.5) overlaps with Ground Cherry's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.7%) — Ground Cherry will thrive.

How to Plant Ground Cherry

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

Succession Planting Ground Cherry

2
successive plantings in your 166-day season

Sow every 7.4 weeks. Last sowing by Jul 23 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 677 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" 0" ❄️ Dormant
Feb 2.6" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 4.3" 1.7" 2.6" 🚿 Regular watering
May 4.3" 1.4" 2.9" 🚿 Regular watering
Jun 4.3" 0.9" 3.4" 🚿 Regular watering
Jul 4.3" 0.3" 4" 🚿 Regular watering
Aug 4.3" 0.3" 4" 🚿 Regular watering
Sep 4.3" 0.9" 3.4" 🚿 Regular watering
Oct 4.3" 1.9" 2.4" 🚿 Regular watering
Nov 3" 0" ❄️ Dormant
Dec 3.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Columbia 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 ~1,269 GDD — county provides 2,905 GDD Excellent fit

Ground Cherry Planting Timeline — Columbia County, WA

Ground Cherry Planting Calendar

Activity When Date Range
Transplant Outdoors May 19 May 19 – Jun 2
Harvest July 28 Jul 28 – Sep 22

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

65–80 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

166 days in Columbia County

Growing Tips for Ground Cherry in Columbia County

Direct sow Ground Cherry outdoors after April 28 in Columbia 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.

Columbia County receives only 21" of rain annually. Ground Cherry needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Columbia County, WA?

Columbia County is in Zone 7a with an average last frost of April 28. Plan your Ground Cherry planting based on this frost date — see the calendar above for exact timing.

What planting zone is Columbia County, WA?

Columbia County, Washington is in USDA Hardiness Zone 7a. The average last spring frost is April 28 and first fall frost is October 11.

🌱

Your Columbia County Garden Planner — Free

A 24-page printable planner built for Columbia 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 Columbia County, WA. 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.