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When to Plant Borage in Harney County, OR

Harney County, Oregon Zone 6a May

What to do in May

A quick May briefing for Harney County, Oregon gardeners — what's urgent, what's next, and what can wait.

Avg. last frost June 17
Avg. first frost September 6
Soil temp (4") 60°F
Watering High
Pest pressure Low
Daylight 14.5 hrs
A few tasks this May that'll pay off in June
  • Transplants going out: borage
  • Direct-sowing: borage
  • Fall sowing: borage

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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.

Harney County, Oregon is in USDA Zone 6a. The average last spring frost is June 17 and the first fall frost is September 6, giving you a growing season of approximately 81 days.

At an elevation of 679 feet, Harney County receives approximately 22.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Borage during the growing season.

Harney County, OR (Zone 6a) Very short season
81 days
Last Spring Frost June 17
81 growing days
First Fall Frost September 6
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Harney County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: May 8 Transplant: Jun 5 🍅 Harvest: Jul 31 – Sep 18
Recommended (50%) ✗ May not fit
Start indoors: May 13 Transplant: Jun 10 🍅 Harvest: Aug 5 – Sep 23
Safe Start (90%) ✗ May not fit
Start indoors: May 20 Transplant: Jun 17 🍅 Harvest: Aug 12 – Sep 30

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 Harney County

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

Soil pH

Your soil pH (5.6–6.4) overlaps with Borage's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.5%) — Borage will thrive.

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.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 3.3" 0" ❄️ Dormant
Feb 2.2" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 1.4" 0" ❄️ Dormant
Jun 2.2" 0.9" 1.3" 🚿 Regular watering
Jul 2.2" 0.4" 1.8" 🚿 Regular watering
Aug 2.2" 0.4" 1.8" 🚿 Regular watering
Sep 2.2" 0.9" 1.3" 🚿 Regular watering
Oct 2" 0" ❄️ Dormant
Nov 3.6" 0" ❄️ Dormant
Dec 3.7" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Harney 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 ~839 GDD — county provides 1,235 GDD Excellent fit

Borage Planting Timeline — Harney County, OR

Borage Planting Calendar

Activity When Date Range
Start Indoors May 13 May 13 – May 27
Transplant Outdoors June 10 Jun 10 – Jun 24
Direct Sow June 3 Jun 3 – Jun 24
Harvest August 5 Aug 5 – Sep 23
Fall Sowing June 28 Jun 28 – Jul 12

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

50–60 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

81 days in Harney County

Growing Tips for Borage in Harney County

Direct sow Borage outdoors after June 17 in Harney 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 Harney County, OR?

Harney County is in Zone 6a with an average last frost of June 17. Plan your Borage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Harney County, OR?

Harney County, Oregon is in USDA Hardiness Zone 6a. The average last spring frost is June 17 and first fall frost is September 6.

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Your Harney County Garden Planner — Free

A 24-page printable planner built for Harney County (Zone 6a). 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 Harney County, OR. 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.