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When to Plant Eggplant in San Francisco County, CA

San Francisco County, California Zone 10b May

San Francisco County, California gardeners: here's your May plan

Your San Francisco County, California garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost February 23
Avg. first frost November 27
Soil temp (4") 78°F
Watering Critical
Pest pressure High
Daylight 14 hrs
  1. Collect eggplant at their peak

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Get ahead of June
  • First harvests: eggplant

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Eggplant is a heat-loving solanaceous crop that produces glossy fruits in purple, white, or striped varieties. It requires long, warm growing seasons for best production.

San Francisco County, California is in USDA Zone 10b. The average last spring frost is February 23 and the first fall frost is November 27, giving you a growing season of approximately 277 days.

At an elevation of 412 feet, San Francisco County receives approximately 13.5 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Eggplant during the growing season. With low rainfall, drip irrigation is essential for growing Eggplant successfully. Mulch heavily to conserve soil moisture.

San Francisco County, CA (Zone 10b) Year-round
277 days
Last Spring Frost February 23
277 growing days
First Fall Frost November 27
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San Francisco County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (153 days to spare)
Start indoors: Dec 22 Transplant: Feb 9 🍅 Harvest: Apr 20 – Jun 22
Recommended (50%) ✓ Fits season (137 days to spare)
Start indoors: Jan 12 Transplant: Mar 2 🍅 Harvest: May 11 – Jul 13
Safe Start (90%) ✓ Fits season (119 days to spare)
Start indoors: Feb 23 Transplant: Apr 13 🍅 Harvest: Jun 22 – Aug 24

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 Francisco County

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

Soil pH

Your soil pH (6.2–7.2) overlaps with Eggplant's range (5.5–7.0), though not a perfect match.

Soil Texture

The loam soil in San Francisco County is excellent for Eggplant — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.0%). Annual compost additions will help Eggplant.

How to Plant Eggplant

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Eggplant

5
successive plantings in your 277-day season

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

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.2″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 2,660 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Eggplant

Eggplant needs approximately 1.1 inches of water per week (4.8" per month). Here's how your county's rainfall compares month by month.

Month Eggplant Needs Rainfall You Supplement Action
Jan 2.3" 0" ❄️ Dormant
Feb 4.8" 3.1" 1.7" 💧 Light watering
Mar 4.8" 2.2" 2.6" 🚿 Regular watering
Apr 4.8" 1.2" 3.6" 🚿 Regular watering
May 4.8" 0.3" 4.5" 🚿 Regular watering
Jun 4.8" 0.1" 4.7" 🚿 Regular watering
Jul 4.8" 0" 4.8" 🚿 Regular watering
Aug 4.8" 0" 4.8" 🚿 Regular watering
Sep 4.8" 0.1" 4.7" 🚿 Regular watering
Oct 4.8" 0.6" 4.2" 🚿 Regular watering
Nov 4.8" 1.4" 3.4" 🚿 Regular watering
Dec 2.1" 0" ❄️ Dormant

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

Eggplant 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.

Eggplant needs ~1,088 GDD — county provides 4,031 GDD Excellent fit

Eggplant Planting Timeline — San Francisco County, CA

Eggplant Planting Calendar

Activity When Date Range
Start Indoors January 12 Jan 12 – Jan 26
Transplant Outdoors March 2 Mar 2 – Mar 16
Direct Sow February 23 Feb 23 – Mar 16
Harvest May 11 May 11 – Jul 13

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · 2-3 times/week

📅 Days to Maturity

65–85 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 10b

📆 Growing Season

277 days in San Francisco County

Growing Tips for Eggplant in San Francisco County

Direct sow Eggplant outdoors after February 23 in San Francisco County when soil has warmed and frost danger has passed.

Common pests for Eggplant in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.

San Francisco County receives only 14" of rain annually. Eggplant needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 8-10 weeks before last frost. Transplant only after nighttime temperatures stay above 55F. Mulch to retain moisture and warmth around roots.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel
  • Kohlrabi

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Eggplant in San Francisco County, CA?

San Francisco County is in Zone 10b with an average last frost of February 23. Plan your Eggplant planting based on this frost date — see the calendar above for exact timing.

What planting zone is San Francisco County, CA?

San Francisco County, California is in USDA Hardiness Zone 10b. The average last spring frost is February 23 and first fall frost is November 27.

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Your San Francisco County Garden Planner — Free

A 24-page printable planner built for San Francisco County (Zone 10b). 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 San Francisco County, CA. 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.