Blog

When to Plant Borage in Clatsop County, OR

Clatsop County, Oregon Zone 9a May

Top priorities for Clatsop County, Oregon gardeners in May

Here's what deserves your attention in Clatsop County, Oregon this month. Everything below is tailored to Zone 9a and timed around your local frost dates.

Avg. last frost April 12
Avg. first frost November 4
Soil temp (4") 72°F
Watering Moderate
Pest pressure High
Daylight 14.8 hrs
  1. Indoor seed-starting week for borage

    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.

Get ahead of June
  • 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.

Clatsop County, Oregon is in USDA Zone 9a. The average last spring frost is April 12 and the first fall frost is November 4, giving you a growing season of approximately 206 days.

At an elevation of 412 feet, Clatsop County receives approximately 54.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°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.

Clatsop County, OR (Zone 9a) Long season
206 days
Last Spring Frost April 12
206 growing days
First Fall Frost November 4

Clatsop County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (112 days to spare)
Start indoors: Mar 4 Transplant: Mar 25 🍅 Harvest: May 20 – Jul 8
Recommended (50%) ✓ Fits season (108 days to spare)
Start indoors: Mar 15 Transplant: Apr 5 🍅 Harvest: May 31 – Jul 19
Safe Start (90%) ✓ Fits season (116 days to spare)
Start indoors: Apr 2 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 Clatsop County

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

Soil pH

Your soil pH (5.6–6.7) overlaps with Borage's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.9%) — Borage will thrive.

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

4
successive plantings in your 206-day season

Sow every 5.7 weeks. Last sowing by Sep 05 to harvest before frost.

For a dedicated fall crop, sow by Sep 09.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.1″/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 8.4" 0" ❄️ Dormant
Feb 5.2" 0" ❄️ Dormant
Mar 4.8" 0" ❄️ Dormant
Apr 2.2" 3.8" 0" ✅ Rainfall sufficient
May 2.2" 3.6" 0" ✅ Rainfall sufficient
Jun 2.2" 2.1" 0.1" 💧 Light watering
Jul 2.2" 0.9" 1.3" 🚿 Regular watering
Aug 2.2" 1.1" 1.1" 🚿 Regular watering
Sep 2.2" 2.4" 0" ✅ Rainfall sufficient
Oct 2.2" 4.2" 0" ✅ Rainfall sufficient
Nov 2.2" 8.4" 0" ✅ Rainfall sufficient
Dec 9.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Clatsop 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 ~798 GDD — county provides 2,987 GDD Excellent fit

Borage Planting Timeline — Clatsop County, OR

Borage Planting Calendar

Activity When Date Range
Start Indoors March 15 Mar 15 – Mar 29
Transplant Outdoors April 5 Apr 5 – Apr 19
Direct Sow March 22 Mar 22 – Apr 12
Harvest May 31 May 31 – Jul 19
Fall Sowing September 9 Sep 9 – Sep 23

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May Harvest
June Harvest
July Harvest
August
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 9a

📆 Growing Season

206 days in Clatsop County

Growing Tips for Borage in Clatsop County

Direct sow Borage outdoors after April 12 in Clatsop 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 Clatsop County, OR?

Clatsop County is in Zone 9a with an average last frost of April 12. Plan your Borage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clatsop County, OR?

Clatsop County, Oregon is in USDA Hardiness Zone 9a. The average last spring frost is April 12 and first fall frost is November 4.

🌱

Your Clatsop County Garden Planner — Free

A 24-page printable planner built for Clatsop 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 Clatsop 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.