Blog

When to Plant Borage in Kings County, CA

Kings County, California Zone 9a April

April in Kings County, California — your action list

April is a pivotal month for Kings County, California gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost February 14
Avg. first frost December 2
Soil temp (4") 62°F
Watering High
Pest pressure High
Daylight 12.9 hrs
  1. Harvest borage as they ripen

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Get ahead of May
  • First harvests: borage

Instant PDF download. No spam, unsubscribe any time.

Borage is a self-seeding annual herb with star-shaped blue flowers that attract pollinators. Its leaves have a cucumber-like flavor and the flowers are edible.

Kings County, California is in USDA Zone 9a. The average last spring frost is February 14 and the first fall frost is December 2, giving you a growing season of approximately 291 days.

At an elevation of 2,065 feet, Kings County receives approximately 18.8 inches of rainfall annually with predominantly loam soil. Summer highs average 102°F, so Borage may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Borage successfully. Mulch heavily to conserve soil moisture.

Kings County, CA (Zone 9a) Year-round
291 days
Last Spring Frost February 14
291 growing days
First Fall Frost December 2
Share this guide:

Kings County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (199 days to spare)
Start indoors: Jan 3 Transplant: Jan 24 🍅 Harvest: Mar 21 – May 9
Recommended (50%) ✓ Fits season (193 days to spare)
Start indoors: Jan 17 Transplant: Feb 7 🍅 Harvest: Apr 4 – May 23
Safe Start (90%) ✓ Fits season (191 days to spare)
Start indoors: Feb 8 Transplant: Mar 1 🍅 Harvest: Apr 26 – Jun 14

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 Kings County

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

Soil pH

Your soil pH (6.5–7.4) overlaps with Borage's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.1%). Annual compost additions will help Borage.

How to Plant Borage

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

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

Succession Planting Borage

7
successive plantings in your 291-day season

Sow every 5.7 weeks. Last sowing by Oct 03 to harvest before frost.

For a dedicated fall crop, sow by Oct 07.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.3″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 716 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Borage

Borage needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Borage Needs Rainfall You Supplement Action
Jan 3.6" 0" ❄️ Dormant
Feb 2.2" 4" 0" ✅ Rainfall sufficient
Mar 2.2" 3.2" 0" ✅ Rainfall sufficient
Apr 2.2" 1.4" 0.8" 💧 Light watering
May 2.2" 0.5" 1.7" 🚿 Regular watering
Jun 2.2" 0.1" 2.1" 🚿 Regular watering
Jul 2.2" 0" 2.2" 🚿 Regular watering
Aug 2.2" 0" 2.2" 🚿 Regular watering
Sep 2.2" 0.2" 2" 🚿 Regular watering
Oct 2.2" 0.7" 1.5" 🚿 Regular watering
Nov 2.2" 1.9" 0.3" 💧 Light watering
Dec 2.2" 3.2" 0" ✅ Rainfall sufficient

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

Borage 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.

Borage needs ~1,458 GDD — county provides 7,738 GDD Excellent fit

Borage Planting Timeline — Kings County, CA

Borage Planting Calendar

Activity When Date Range
Start Indoors January 17 Jan 17 – Jan 31
Transplant Outdoors February 7 Feb 7 – Feb 21
Direct Sow January 24 Jan 24 – Feb 14
Harvest April 4 Apr 4 – May 23
Fall Sowing October 7 Oct 7 – Oct 21

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

50–60 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

291 days in Kings County

Growing Tips for Borage in Kings County

Direct sow Borage outdoors after February 14 in Kings County when soil has warmed and frost danger has passed.

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

General growing tips

Direct sow in spring as borage does not transplant well. Allow some plants to go to seed for next year. Young leaves are best; older leaves become bristly.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Borage in Kings County, CA?

Kings County is in Zone 9a with an average last frost of February 14. Plan your Borage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Kings County, CA?

Kings County, California is in USDA Hardiness Zone 9a. The average last spring frost is February 14 and first fall frost is December 2.

🌱

Your Kings County Garden Planner — Free

A 24-page printable planner built for Kings County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Kings 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.