Blog

When to Plant Borage in Douglas County, OR

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.

Douglas County, Oregon is in USDA Zone 8a. The average last spring frost is April 4 and the first fall frost is November 5, giving you a growing season of approximately 215 days.

At an elevation of 377 feet, Douglas County receives approximately 52.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Borage during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Borage root diseases.

Douglas County, OR (Zone 8a) Long season
215 days
Last Spring Frost April 4
215 growing days
First Fall Frost November 5

Douglas County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (113 days to spare)
Start indoors: Feb 21 Transplant: Mar 21 🍅 Harvest: May 16 – Jul 4
Recommended (50%) ✓ Fits season (117 days to spare)
Start indoors: Feb 28 Transplant: Mar 28 🍅 Harvest: May 23 – Jul 11
Safe Start (90%) ✓ Fits season (123 days to spare)
Start indoors: Mar 26 Transplant: Apr 23 🍅 Harvest: Jun 18 – Aug 6

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 Douglas County

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

Soil pH

Your soil pH (5.8โ€“6.4) overlaps with Borage's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Douglas County is excellent for Borage โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.4%) โ€” 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.

Succession Planting Borage

5
successive plantings in your 215-day season

Sow every 5.7 weeks. Last sowing by Sep 06 to harvest before frost.

For a dedicated fall crop, sow by Aug 27.

Plant Water Budget

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

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 โ€” 8.6" 0" โ„๏ธ Dormant
Feb โ€” 6.2" 0" โ„๏ธ Dormant
Mar โ€” 4.9" 0" โ„๏ธ Dormant
Apr 2.2" 4.3" 0" โœ… Rainfall sufficient
May 2.2" 3.4" 0" โœ… Rainfall sufficient
Jun 2.2" 2.3" 0" โœ… Rainfall sufficient
Jul 2.2" 0.8" 1.4" ๐Ÿšฟ Regular watering
Aug 2.2" 1" 1.2" ๐Ÿšฟ Regular watering
Sep 2.2" 2.2" 0" โœ… Rainfall sufficient
Oct 2.2" 4" 0" โœ… Rainfall sufficient
Nov 2.2" 7.6" 0" โœ… Rainfall sufficient
Dec โ€” 7.4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Nov in Douglas County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~962 GDD — county provides 3,762 GDD Excellent fit

Borage Planting Timeline โ€” Douglas County, OR

Borage Planting Calendar

Activity When Date Range
Start Indoors February 28 Feb 28 โ€“ Mar 14
Transplant Outdoors March 28 Mar 28 โ€“ Apr 11
Direct Sow March 21 Mar 21 โ€“ Apr 11
Harvest May 23 May 23 โ€“ Jul 11
Fall Sowing August 27 Aug 27 โ€“ Sep 10

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

50โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

215 days in Douglas County

Growing Tips for Borage in Douglas County

Direct sow Borage outdoors after April 04 in Douglas 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 Douglas County, OR?

Douglas County is in Zone 8a with an average last frost of April 4. Plan your Borage planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Douglas County, OR?

Douglas County, Oregon is in USDA Hardiness Zone 8a. The average last spring frost is April 4 and first fall frost is November 5.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Douglas County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Douglas County, OR. Local conditions may vary. Last updated: April 2026.