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When to Plant Ground Cherry in San Joaquin County, CA

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

San Joaquin County, California is in USDA Zone 9a. The average last spring frost is February 4 and the first fall frost is December 6, giving you a growing season of approximately 305 days.

At an elevation of 220 feet, San Joaquin County receives approximately 15 inches of rainfall annually with predominantly loam soil. Summer highs average 93ยฐF, providing good warmth for Ground Cherry during the growing season. With low rainfall, drip irrigation is essential for growing Ground Cherry successfully. Mulch heavily to conserve soil moisture.

San Joaquin County, CA (Zone 9a) Year-round
305 days
Last Spring Frost February 4
305 growing days
First Fall Frost December 6

San Joaquin County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (175 days to spare)
Transplant: Feb 1 🍅 Harvest: Apr 12 – Jun 7
Recommended (50%) ✓ Fits season (165 days to spare)
Transplant: Feb 18 🍅 Harvest: Apr 29 – Jun 24
Safe Start (90%) ✓ Fits season (149 days to spare)
Transplant: Mar 19 🍅 Harvest: May 28 – Jul 23

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 San Joaquin County

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

Soil pH

Your soil pH (6.4โ€“7.8) overlaps with Ground Cherry's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

The loam soil in San Joaquin County is excellent for Ground Cherry โ€” 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

5
successive plantings in your 305-day season

Sow every 7.4 weeks. Last sowing by Sep 17 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.2″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 2,595 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

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 โ€” 2.9" 0" โ„๏ธ Dormant
Feb 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
Mar 4.3" 2.6" 1.7" ๐Ÿ’ง Light watering
Apr 4.3" 1.2" 3.1" ๐Ÿšฟ Regular watering
May 4.3" 0.4" 3.9" ๐Ÿšฟ Regular watering
Jun 4.3" 0.1" 4.2" ๐Ÿšฟ Regular watering
Jul 4.3" 0" 4.3" ๐Ÿšฟ Regular watering
Aug 4.3" 0" 4.3" ๐Ÿšฟ Regular watering
Sep 4.3" 0.2" 4.1" ๐Ÿšฟ Regular watering
Oct 4.3" 0.7" 3.6" ๐Ÿšฟ Regular watering
Nov 4.3" 1.3" 3" ๐Ÿšฟ Regular watering
Dec 4.3" 2.6" 1.7" ๐Ÿ’ง Light watering

Water needs are for active growing months only (Febโ€“Dec in San Joaquin County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,432 GDD — county provides 6,043 GDD Excellent fit

Ground Cherry Planting Timeline โ€” San Joaquin County, CA

Ground Cherry Planting Calendar

Activity When Date Range
Transplant Outdoors February 18 Feb 18 โ€“ Mar 4
Harvest April 29 Apr 29 โ€“ Jun 24

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Transplant Outdoors
March Transplant Outdoors
April Harvest
May Harvest
June Harvest
July โ€”
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

65โ€“80 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

305 days in San Joaquin County

Growing Tips for Ground Cherry in San Joaquin County

Direct sow Ground Cherry outdoors after February 04 in San Joaquin 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.

San Joaquin County receives only 15" of rain annually. Ground Cherry needs consistent moisture โ€” 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 San Joaquin County, CA?

San Joaquin County is in Zone 9a with an average last frost of February 4. Plan your Ground Cherry planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is San Joaquin County, CA?

San Joaquin County, California is in USDA Hardiness Zone 9a. The average last spring frost is February 4 and first fall frost is December 6.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help San Joaquin County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for San Joaquin County, CA. Local conditions may vary. Last updated: April 2026.