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When to Plant Raspberries in Kern County, CA

Kern County, California Zone 9b May

Top priorities for Kern County, California gardeners in May

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

Avg. last frost February 28
Avg. first frost November 29
Soil temp (4") 78°F
Watering Critical
Pest pressure High
Daylight 13.9 hrs

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Raspberries are beloved bramble fruits producing sweet, delicate berries in red, golden, black, and purple varieties. They spread by underground runners and are very productive.

Kern County, California is in USDA Zone 9b. The average last spring frost is February 28 and the first fall frost is November 29, giving you a growing season of approximately 274 days.

At an elevation of 389 feet, Kern County receives approximately 16.9 inches of rainfall annually with predominantly loam soil. Summer highs average 102°F, so Raspberries may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Raspberries successfully. Mulch heavily to conserve soil moisture.

Kern County, CA (Zone 9b) Year-round
274 days
Last Spring Frost February 28
274 growing days
First Fall Frost November 29
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Kern County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Mar 6
Recommended (50%) ✓ Fits season
Transplant: Mar 14
Safe Start (90%) ✓ Fits season
Transplant: Apr 21

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 Kern County

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

Soil pH

Your soil pH (6.2–7.7) is more alkaline than Raspberries prefers (5.5–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Kern County is excellent for Raspberries — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Raspberries.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Raspberries.

How to Plant Raspberries

24"
Between Plants
72"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.3″/week
You supply
1.3″/week
Watering frequency 2-3 times/week
Season total 3,060 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Raspberries

Raspberries needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Raspberries Needs Rainfall You Supplement Action
Jan 3.9" 0" ❄️ Dormant
Feb 4.3" 3.4" 0.9" 💧 Light watering
Mar 4.3" 2.4" 1.9" 💧 Light watering
Apr 4.3" 1.2" 3.1" 🚿 Regular watering
May 4.3" 0.5" 3.8" 🚿 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" 0.2" 4.1" 🚿 Regular watering
Oct 4.3" 0.7" 3.6" 🚿 Regular watering
Nov 4.3" 1.7" 2.6" 🚿 Regular watering
Dec 2.8" 0" ❄️ Dormant

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

Raspberries 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.

Raspberries needs ~14,509 GDD — county provides 7,287 GDD May not mature

Raspberries Planting Timeline — Kern County, CA

Raspberries Planting Calendar

Activity When Date Range
Transplant Outdoors March 14 Mar 14 – Mar 28

· 24" apart · Rows 72" apart

Month-by-Month Timeline

MonthActivities
January
February
March Transplant Outdoors
April
May
June
July
August
September
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

365–730 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9b

📆 Growing Season

274 days in Kern County

Growing Tips for Raspberries in Kern County

Direct sow Raspberries outdoors after February 28 in Kern County when soil has warmed and frost danger has passed.

With summer highs reaching 102°F in Kern County, provide afternoon shade for Raspberries and water deeply in the morning.

Your 275.0-day growing season in Kern County is tight for Raspberries (365.0-730.0 days to maturity). Start indoors and choose early-maturing varieties.

Kern County receives only 17" of rain annually. Raspberries needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Provide a trellis for support. Prune summer-bearing types by removing spent canes after harvest. For ever-bearing types, mow all canes in late winter for a single fall crop.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Raspberries in Kern County, CA?

Kern County is in Zone 9b with an average last frost of February 28. Plan your Raspberries planting based on this frost date — see the calendar above for exact timing.

What planting zone is Kern County, CA?

Kern County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 28 and first fall frost is November 29.

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Your Kern County Garden Planner — Free

A 24-page printable planner built for Kern 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 Kern 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.