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When to plant Borage in Clearwater County, MN

Plant Borage in Clearwater County from May 8 to May 29 in spring. Clearwater County sits in USDA Zone 3b, with last frost around May 15 and first frost on September 28. A second sowing from July 6 to July 20 extends the harvest into fall.

When to Plant Borage in Clearwater County, MN

Clearwater County, Minnesota Zone 3b July

Top priorities for Clearwater County, Minnesota gardeners in July

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

Avg. last frost May 15
Avg. first frost September 28
Soil temp (4") 68°F
Watering Moderate
Pest pressure Moderate
Daylight 15.4 hrs
  1. Bring in the borage

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

  2. Sow borage for an autumn harvest

    Count back from your first frost (September 28) — these need to mature before the cold arrives.

Coming up in August — start thinking about
  • 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.

Clearwater County, Minnesota is in USDA Zone 3b. The average last spring frost is May 15 and the first fall frost is September 28, giving you a growing season of approximately 136 days.

At an elevation of 1,074 feet, Clearwater County receives approximately 33.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Borage to ensure they mature before fall.

Clearwater County, MN (Zone 3b) Short season
136 days
Last Spring Frost May 15
136 growing days
First Fall Frost September 28

Clearwater County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Borage Planting Risk Windows

Early Start (70% safe) ✓ Fits season (38 days to spare)
Start indoors: Mar 27 Transplant: May 1 🍅 Harvest: Jun 26 – Aug 14
Recommended (50%) ✓ Fits season (38 days to spare)
Start indoors: Apr 3 Transplant: May 8 🍅 Harvest: Jul 3 – Aug 21
Safe Start (90%) ✓ Fits season (40 days to spare)
Start indoors: Apr 16 Transplant: May 21 🍅 Harvest: Jul 16 – Sep 3

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 Clearwater County

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

Soil pH

Your soil pH (6.2–7.2) overlaps with Borage's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Borage.

Organic Matter

Organic matter is excellent (4.6%) — Borage will thrive.

How to Plant Borage

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

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Borage

3
successive plantings in your 136-day season

Sow every 5.7 weeks. Last sowing by Jul 30 to harvest before frost.

For a dedicated fall crop, sow by Jul 06.

Borage Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/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 1.5" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.8" 0" ❄️ Dormant
May 2.2" 4.2" 0" ✅ Rainfall sufficient
Jun 2.2" 3.8" 0" ✅ Rainfall sufficient
Jul 2.2" 3.6" 0" ✅ Rainfall sufficient
Aug 2.2" 3.8" 0" ✅ Rainfall sufficient
Sep 2.2" 3.3" 0" ✅ Rainfall sufficient
Oct 2.5" 0" ❄️ Dormant
Nov 2.6" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Clearwater 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 ~550 GDD — county provides 1,360 GDD Excellent fit

Borage Planting Timeline — Clearwater County, MN

Borage Planting Calendar

Activity When Date Range
Start Indoors April 3 Apr 3 – Apr 17
Transplant Outdoors May 8 May 8 – May 22
Direct Sow May 8 May 8 – May 29
Harvest July 3 Jul 3 – Aug 21
Fall Sowing July 6 Jul 6 – Jul 20

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Transplant Outdoors Direct Sow
June
July Fall Sowing Harvest
August Harvest
September
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 3b

📆 Growing Season

136 days in Clearwater County

Growing Tips for Borage in Clearwater County

Direct sow Borage outdoors after May 15 in Clearwater 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 Clearwater County, MN?

Clearwater County is in Zone 3b with an average last frost of May 15. Plan your Borage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clearwater County, MN?

Clearwater County, Minnesota is in USDA Hardiness Zone 3b. The average last spring frost is May 15 and first fall frost is September 28.

When should I plant Borage in Clearwater County, MN?

In Clearwater County, MN, plant Borage after the last frost (around May 15) and before the first frost (around September 28). Best results when soil holds above 50°F.

What growing zone is Clearwater County, MN for Borage?

Clearwater County sits in USDA Zone 3b. Borage grows reliably in zones 3a through 11b, so it's a good fit here.

Can Borage grow in Clearwater County's climate?

Yes — Borage grows well in Clearwater County's temperate climate. Clearwater County averages a 136-day frost-free season, with last frost around May 15 and first frost around September 28.

🌱

Your Clearwater County Garden Planner — Free

A 22-page printable planner built for Clearwater County (Zone 3b). 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 Clearwater County, MN. Local conditions may vary. Last updated: July 2026.

Sources & credits

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