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When to Plant Borage in Douglas County, OR

Douglas County, Oregon Zone 8b May

May in the garden — Douglas County, Oregon

Your Douglas County, Oregon garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost April 4
Avg. first frost November 5
Soil temp (4") 73°F
Watering Moderate
Pest pressure High
Daylight 14.5 hrs
  1. Start borage indoors

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

  2. Collect borage at their peak

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

June will be here before you know it — start on
  • First harvests: 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.

Douglas County, Oregon is in USDA Zone 8b. 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 90°F, 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 8b) 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 (5.8–6.4) overlaps with Borage's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.4%) — 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 8.6" 0" ❄️ Dormant
Feb 6.2" 0" ❄️ Dormant
Mar 4.9" 0" ❄️ Dormant
Apr 2.2" 4.3" 0" ✅ Rainfall sufficient
May 2.2" 3.4" 0" ✅ Rainfall sufficient
Jun 2.2" 2.3" 0" ✅ Rainfall sufficient
Jul 2.2" 0.8" 1.4" 🚿 Regular watering
Aug 2.2" 1" 1.2" 🚿 Regular watering
Sep 2.2" 2.2" 0" ✅ Rainfall sufficient
Oct 2.2" 4" 0" ✅ Rainfall sufficient
Nov 2.2" 7.6" 0" ✅ Rainfall sufficient
Dec 7.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Douglas 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 ~962 GDD — county provides 3,762 GDD Excellent fit

Borage Planting Timeline — Douglas County, OR

Borage Planting Calendar

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

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

Month-by-Month Timeline

MonthActivities
January
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
November
December

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 8b

📆 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 8b with an average last frost of April 4. Plan your Borage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Douglas County, OR?

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

🌱

Your Douglas County Garden Planner — Free

A 24-page printable planner built for Douglas 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.

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 Douglas 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.