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When to Plant Scallions in Del Norte County, CA

Del Norte County, California Zone 9b May

May in Del Norte County, California — your action list

Here's what deserves your attention in Del Norte County, California this month. Everything below is tailored to Zone 9b and timed around your local frost dates.

Avg. last frost March 27
Avg. first frost November 20
Soil temp (4") 71°F
Watering Critical
Pest pressure High
Daylight 14.4 hrs
  1. Harvest scallions as they ripen

    If you can't use it all right away, check the food-preservation section of your planner.

To set up a strong June, finish these tasks
  • First harvests: scallions

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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.

Del Norte County, California is in USDA Zone 9b. The average last spring frost is March 27 and the first fall frost is November 20, giving you a growing season of approximately 238 days.

At an elevation of 72 feet, Del Norte County receives approximately 43.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 89°F, providing good warmth for Scallions during the growing season. Sandy soil warms quickly in spring — great for early planting — but Scallions will need more frequent watering and organic matter to retain nutrients.

Del Norte County, CA (Zone 9b) Long season
238 days
Last Spring Frost March 27
238 growing days
First Fall Frost November 20

Del Norte County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.9-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (153 days to spare)
Start indoors: Feb 5 Transplant: Mar 5 🍅 Harvest: Apr 30 – May 28
Recommended (50%) ✓ Fits season (154 days to spare)
Start indoors: Feb 27 Transplant: Mar 27 🍅 Harvest: May 22 – Jun 19
Safe Start (90%) ✓ Fits season (143 days to spare)
Start indoors: Apr 6 Transplant: May 4 🍅 Harvest: Jun 29 – Jul 27

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 Del Norte County

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

Soil pH

Your soil pH (5.9–7.0) overlaps with Scallions's range (6.0–7.0), though not a perfect match.

Soil Texture

Sandy soil in Del Norte County warms quickly in spring but drains fast. Scallions will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Scallions.

How to Plant Scallions

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Scallions

5
successive plantings in your 238-day season

Sow every 5.7 weeks. Last sowing by Sep 11 to harvest before frost.

For a dedicated fall crop, sow by Sep 25.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 481 gal / 100 sq ft

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 8.3" 0" ❄️ Dormant
Feb 9.9" 0" ❄️ Dormant
Mar 4.3" 5.8" 0" ✅ Rainfall sufficient
Apr 4.3" 3.5" 0.8" 💧 Light watering
May 4.3" 1.1" 3.2" 🚿 Regular watering
Jun 4.3" 0.3" 4" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.4" 3.9" 🚿 Regular watering
Oct 4.3" 1.9" 2.4" 🚿 Regular watering
Nov 4.3" 4.7" 0" ✅ Rainfall sufficient
Dec 7.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Del Norte 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 needs ~1,005 GDD — county provides 3,986 GDD Excellent fit

Scallions Planting Timeline — Del Norte County, CA

Scallions Planting Calendar

Activity When Date Range
Start Indoors February 27 Feb 27 – Mar 13
Transplant Outdoors March 27 Mar 27 – Apr 10
Direct Sow March 6 Mar 6 – Mar 27
Harvest May 22 May 22 – Jun 19
Fall Sowing September 25 Sep 25 – Oct 9

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

238 days in Del Norte County

Growing Tips for Scallions in Del Norte County

Direct sow Scallions outdoors after March 27 in Del Norte County when soil has warmed and frost danger has passed.

Sandy soil in Del Norte County dries quickly — mulch Scallions with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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

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

  • Peas
  • Green Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Scallions in Del Norte County, CA?

Del Norte County is in Zone 9b with an average last frost of March 27. Plan your Scallions planting based on this frost date — see the calendar above for exact timing.

What planting zone is Del Norte County, CA?

Del Norte County, California is in USDA Hardiness Zone 9b. The average last spring frost is March 27 and first fall frost is November 20.

🌱

Your Del Norte County Garden Planner — Free

A 24-page printable planner built for Del Norte County (Zone 9b). 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 Del Norte 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.