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When to Plant Kohlrabi in Del Norte County, CA

Del Norte County, California Zone 8b April

Top priorities for Del Norte County, California gardeners in April

April rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Del Norte County, California.

Avg. last frost March 27
Avg. first frost November 20
Soil temp (4") 62°F
Watering Moderate
Pest pressure High
Daylight 13.1 hrs
Get ahead of May
  • Starting indoors: kohlrabi
  • First harvests: kohlrabi

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Kohlrabi is an unusual brassica that forms a swollen stem above ground with a mild, sweet turnip-like flavor. Both the bulb and tender leaves are edible.

Del Norte County, California is in USDA Zone 8b. 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 Kohlrabi during the growing season. Sandy soil warms quickly in spring — great for early planting — but Kohlrabi will need more frequent watering and organic matter to retain nutrients.

Del Norte County, CA (Zone 8b) Long season
238 days
Last Spring Frost March 27
238 growing days
First Fall Frost November 20
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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: Jan 29 Transplant: Mar 5 🍅 Harvest: Apr 23 – May 28
Recommended (50%) ✓ Fits season (154 days to spare)
Start indoors: Feb 20 Transplant: Mar 27 🍅 Harvest: May 15 – Jun 19
Safe Start (90%) ✓ Fits season (143 days to spare)
Start indoors: Mar 30 Transplant: May 4 🍅 Harvest: Jun 22 – 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 Kohlrabi's growing requirements.

Soil pH

Your soil pH (5.9–7.0) overlaps with Kohlrabi's range (6.0–7.5), though not a perfect match.

Soil Texture

Sandy soil in Del Norte County warms quickly in spring but drains fast. Kohlrabi 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 Kohlrabi.

How to Plant Kohlrabi

0.5"
Planting Depth
4"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Kohlrabi

6
successive plantings in your 238-day season

Sow every 5.1 weeks. Last sowing by Sep 16 to harvest before frost.

For a dedicated fall crop, sow by Sep 11.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Kohlrabi

Kohlrabi needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Kohlrabi Needs Rainfall You Supplement Action
Jan 8.3" 0" ❄️ Dormant
Feb 9.9" 0" ❄️ Dormant
Mar 3" 5.8" 0" ✅ Rainfall sufficient
Apr 3" 3.5" 0" ✅ Rainfall sufficient
May 3" 1.1" 1.9" 🚿 Regular watering
Jun 3" 0.3" 2.7" 🚿 Regular watering
Jul 3" 0" 3" 🚿 Regular watering
Aug 3" 0" 3" 🚿 Regular watering
Sep 3" 0.4" 2.6" 🚿 Regular watering
Oct 3" 1.9" 1.1" 💧 Light watering
Nov 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.

Kohlrabi 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.

Kohlrabi needs ~921 GDD — county provides 3,986 GDD Excellent fit

Kohlrabi Planting Timeline — Del Norte County, CA

Kohlrabi Planting Calendar

Activity When Date Range
Start Indoors February 20 Feb 20 – Mar 6
Transplant Outdoors March 27 Mar 27 – Apr 10
Direct Sow March 13 Mar 13 – Apr 3
Harvest May 15 May 15 – Jun 19
Fall Sowing September 11 Sep 11 – Sep 25

Plant 0.5" deep · 4" apart · Rows 12" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

45–65 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

238 days in Del Norte County

Growing Tips for Kohlrabi in Del Norte County

Direct sow Kohlrabi 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 Kohlrabi with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Your generous 238.0-day season in Del Norte County allows multiple plantings of Kohlrabi. Sow every 22.0 days for continuous harvest.

Common pests for Kohlrabi in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow in spring or fall. Harvest when bulbs are 2-3 inches in diameter for best texture and flavor. Larger bulbs may become woody and fibrous.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

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

Del Norte County is in Zone 8b with an average last frost of March 27. Plan your Kohlrabi 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 8b. The average last spring frost is March 27 and first fall frost is November 20.

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Your Del Norte County Garden Planner — Free

A 24-page printable planner built for Del Norte County (Zone 8b). 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: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.