When to plant Scallions in San Francisco County County,
The best window to plant Scallions in San Francisco County County, is February 2–February 23, when soil warms to 50°F. Last frost typically hits February 23; first frost November 27. A second sowing from October 2 to October 16 extends the harvest into fall.
When to Plant Scallions in San Francisco County, CA
June in the garden — 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 June.
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Survive, don't thrive
June-August is endurance gardening. Keep okra, peppers, sweet potatoes, and southern peas alive. Harvest everything daily before the heat damages produce on the vine.
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Start fall tomato seeds indoors
Yes, indoors — under lights or in AC. They'll be ready to transplant in August when temperatures briefly moderate.
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Add compost to empty beds
Empty beds get a thick layer of compost + mulch to suppress weeds and feed the soil for fall planting.
Scallions (green onions) are mild-flavored alliums harvested for their slender green tops and white bases. They are quick-growing and perfect for succession planting.
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 Scallions during the growing season. With low rainfall, drip irrigation is essential for growing Scallions successfully. Mulch heavily to conserve soil moisture.
San Francisco County Soil Profile
Soil Type
Loam
Soil pH
6.2-7.2
Drainage
Well Drained
Scallions Planting Risk Windows
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 Scallions's growing requirements.
Soil pH
Your soil pH (6.2–7.2) overlaps with Scallions's range (6.0–7.0), though not a perfect match.
Soil Texture
The loam soil in San Francisco County is excellent for Scallions — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.0%). Annual compost additions will help Scallions.
How to Plant Scallions
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Scallions
Sow every 5.7 weeks. Last sowing by Sep 18 to harvest before frost.
For a dedicated fall crop, sow by Oct 02.
Scallions Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Scallions
Scallions needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Scallions Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 2.3" | 0" | ❄️ Dormant |
| Feb | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Mar | 4.3" | 2.2" | 2.1" | 💧 Light watering |
| Apr | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| May | 4.3" | 0.3" | 4" | 🚿 Regular watering |
| Jun | 4.3" | 0.1" | 4.2" | 🚿 Regular watering |
| Jul | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Aug | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Sep | 4.3" | 0.1" | 4.2" | 🚿 Regular watering |
| Oct | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Nov | 4.3" | 1.4" | 2.9" | 🚿 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.
Scallions 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.
Scallions Planting Timeline — San Francisco County, CA
Scallions Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 26 | Jan 26 – Feb 9 |
| Transplant Outdoors | February 23 | Feb 23 – Mar 9 |
| Direct Sow | February 2 | Feb 2 – Feb 23 |
| Harvest | April 20 | Apr 20 – May 18 |
| Fall Sowing | October 2 | Oct 2 – Oct 16 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors Transplant Outdoors Direct Sow |
| March | Transplant Outdoors |
| April | Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 2-3 times/week
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 10b
📆 Growing Season
277 days in San Francisco County
Growing Tips for Scallions in San Francisco County
Direct sow Scallions outdoors after February 23 in San Francisco County when soil has warmed and frost danger has passed.
Common pests for Scallions in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.
San Francisco County receives only 14" of rain annually. Scallions needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Direct sow every 3 weeks for continuous harvest. Thin to 1 inch apart or grow in clusters. Harvest when pencil-thick by pulling or cutting at soil level.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Scallions in Other Locations
Frequently Asked Questions
When should I plant Scallions in San Francisco County, CA?
San Francisco County is in Zone 10b with an average last frost of February 23. Plan your Scallions 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.
When should I plant Scallions in San Francisco County County, ?
In San Francisco County County, , plant Scallions after the last frost (around February 23) and before the first frost (around November 27). Best results when soil holds above 50°F.
What growing zone is San Francisco County County, for Scallions?
San Francisco County County sits in USDA Zone 10b. Scallions grows reliably in zones 3a through 10b, so it's a good fit here.
Can Scallions grow in San Francisco County County's climate?
Yes — Scallions grows well in San Francisco County County's temperate climate. San Francisco County County averages a 278-day frost-free season, with last frost around February 23 and first frost around November 27.
Your San Francisco County Garden Planner — Free
A 22-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.