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When to Plant Chives in San Francisco County, CA

San Francisco County, California Zone 10b May

Your May planting checklist for San Francisco County, California

Your garden in San Francisco County, California is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost February 23
Avg. first frost November 27
Soil temp (4") 78°F
Watering Critical
Pest pressure High
Daylight 14 hrs
  1. It's harvest week for chives

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

June will be here before you know it — start on
  • First harvests: chives

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Chives are a hardy perennial herb with a mild onion flavor and attractive purple pom-pom flowers. They are one of the easiest herbs to grow and maintain.

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 Chives during the growing season. With low rainfall, drip irrigation is essential for growing Chives 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)
Transplant: Feb 9 🍅 Harvest: Apr 13 – Jun 22
Recommended (50%) ✓ Fits season (137 days to spare)
Transplant: Mar 2 🍅 Harvest: May 4 – Jul 13
Safe Start (90%) ✓ Fits season (119 days to spare)
Transplant: Apr 13 🍅 Harvest: Jun 15 – 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 Chives's growing requirements.

Soil pH

Your soil pH (6.2–7.2) overlaps with Chives's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

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

How to Plant Chives

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

Succession Planting Chives

5
successive plantings in your 277-day season

Sow every 6.9 weeks. Last sowing by Aug 29 to harvest before frost.

Plant Water Budget

Plant needs
0.4″/week
Rainfall provides
0.2″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 582 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Chives

Chives 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 Chives Needs Rainfall You Supplement Action
Jan 2.3" 0" ❄️ Dormant
Feb 1.7" 3.1" 0" ✅ Rainfall sufficient
Mar 1.7" 2.2" 0" ✅ Rainfall sufficient
Apr 1.7" 1.2" 0.5" 💧 Light watering
May 1.7" 0.3" 1.4" 🚿 Regular watering
Jun 1.7" 0.1" 1.6" 🚿 Regular watering
Jul 1.7" 0" 1.7" 🚿 Regular watering
Aug 1.7" 0" 1.7" 🚿 Regular watering
Sep 1.7" 0.1" 1.6" 🚿 Regular watering
Oct 1.7" 0.6" 1.1" 🚿 Regular watering
Nov 1.7" 1.4" 0.3" 💧 Light 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.

Chives 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.

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

Chives Planting Timeline — San Francisco County, CA

Chives Planting Calendar

Activity When Date Range
Transplant Outdoors March 2 Mar 2 – Mar 16
Harvest May 4 May 4 – Jul 13

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

Month-by-Month Timeline

MonthActivities
January
February
March Transplant Outdoors
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

0.4"/week · Only during dry spells

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 10b

📆 Growing Season

277 days in San Francisco County

Growing Tips for Chives in San Francisco County

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

Common pests for Chives in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

Start from seed or divisions in spring. Cut back to 2 inches after flowering to encourage fresh growth. Both the leaves and flowers are edible and delicious.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

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

San Francisco County is in Zone 10b with an average last frost of February 23. Plan your Chives 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.

🌱

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.