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When to Plant Borage in Inyo County, CA

Inyo County, California Zone 8b May

May in Inyo County, California — your action list

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

Avg. last frost January 15
Avg. first frost December 10
Soil temp (4") 57°F
Watering Critical
Pest pressure Moderate
Daylight 13.9 hrs

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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.

Inyo County, California is in USDA Zone 8b. The average last spring frost is January 15 and the first fall frost is December 10, giving you a growing season of approximately 329 days.

At an elevation of 4,562 feet, Inyo County receives approximately 16.4 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Borage during the growing season. With low rainfall, drip irrigation is essential for growing Borage successfully. Mulch heavily to conserve soil moisture.

Inyo County, CA (Zone 8b) Year-round
329 days
Last Spring Frost January 15
329 growing days
First Fall Frost December 10
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Inyo County Soil Profile

Soil Type

Loam

Soil pH

6-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (234 days to spare)
Start indoors: Dec 3 Transplant: Dec 31 🍅 Harvest: Feb 25 – Apr 15
Recommended (50%) ✓ Fits season (231 days to spare)
Start indoors: Dec 11 Transplant: Jan 8 🍅 Harvest: Mar 5 – Apr 23
Safe Start (90%) ✓ Fits season (217 days to spare)
Start indoors: Jan 5 Transplant: Feb 2 🍅 Harvest: Mar 30 – May 18

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 Inyo County

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

Soil pH

Your soil pH (6.0–7.8) overlaps with Borage's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Borage.

How to Plant Borage

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

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

Succession Planting Borage

7
successive plantings in your 329-day season

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

For a dedicated fall crop, sow by Oct 01.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.2″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 1,027 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 2.2" 3.3" 0" ✅ Rainfall sufficient
Feb 2.2" 3.4" 0" ✅ Rainfall sufficient
Mar 2.2" 2.5" 0" ✅ Rainfall sufficient
Apr 2.2" 1.3" 0.9" 💧 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" 0.6" 1.6" 🚿 Regular watering
Nov 2.2" 1.7" 0.5" 💧 Light watering
Dec 2.2" 2.8" 0" ✅ Rainfall sufficient

Water needs are for active growing months only (Jan–Dec in Inyo 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 ~880 GDD — county provides 5,280 GDD Excellent fit

Borage Planting Timeline — Inyo County, CA

Borage Planting Calendar

Activity When Date Range
Start Indoors December 11 Dec 11 – Dec 25
Transplant Outdoors January 8 Jan 8 – Jan 22
Direct Sow January 1 Jan 1 – Jan 22
Harvest March 5 Mar 5 – Apr 23
Fall Sowing October 1 Oct 1 – Oct 15

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · 1-2 times/week

📅 Days to Maturity

50–60 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

329 days in Inyo County

Growing Tips for Borage in Inyo County

Direct sow Borage outdoors after January 15 in Inyo County when soil has warmed and frost danger has passed.

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 Inyo County, CA?

Inyo County is in Zone 8b with an average last frost of January 15. Plan your Borage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Inyo County, CA?

Inyo County, California is in USDA Hardiness Zone 8b. The average last spring frost is January 15 and first fall frost is December 10.

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Your Inyo County Garden Planner — Free

A 24-page printable planner built for Inyo 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 Inyo 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.