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When to Plant Borage in Russell County, KY

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.

Russell County, Kentucky is in USDA Zone 6b. The average last spring frost is April 18 and the first fall frost is October 20, giving you a growing season of approximately 185 days.

At an elevation of 1,514 feet, Russell County receives approximately 47.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Borage during the growing season.

Russell County, KY (Zone 6b) Moderate season
185 days
Last Spring Frost April 18
185 growing days
First Fall Frost October 20

Russell County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (90 days to spare)
Start indoors: Mar 8 Transplant: Apr 5 🍅 Harvest: May 31 – Jul 19
Recommended (50%) ✓ Fits season (87 days to spare)
Start indoors: Mar 14 Transplant: Apr 11 🍅 Harvest: Jun 6 – Jul 25
Safe Start (90%) ✓ Fits season (78 days to spare)
Start indoors: Apr 4 Transplant: May 2 🍅 Harvest: Jun 27 – Aug 15

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 Russell County

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

Soil pH

Your soil pH (5.5โ€“7.0) overlaps with Borage's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Borage.

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

4
successive plantings in your 185-day season

Sow every 5.7 weeks. Last sowing by Aug 21 to harvest before frost.

For a dedicated fall crop, sow by Aug 11.

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 โ€” 4" 0" โ„๏ธ Dormant
Feb โ€” 4" 0" โ„๏ธ Dormant
Mar โ€” 5.1" 0" โ„๏ธ Dormant
Apr 2.2" 3.3" 0" โœ… Rainfall sufficient
May 2.2" 3.3" 0" โœ… Rainfall sufficient
Jun 2.2" 4" 0" โœ… Rainfall sufficient
Jul 2.2" 4.7" 0" โœ… Rainfall sufficient
Aug 2.2" 4.1" 0" โœ… Rainfall sufficient
Sep 2.2" 3.4" 0" โœ… Rainfall sufficient
Oct 2.2" 3.4" 0" โœ… Rainfall sufficient
Nov โ€” 3.7" 0" โ„๏ธ Dormant
Dec โ€” 4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Russell 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 ~921 GDD — county provides 3,098 GDD Excellent fit

Borage Planting Timeline โ€” Russell County, KY

Borage Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 โ€“ Mar 28
Transplant Outdoors April 11 Apr 11 โ€“ Apr 25
Direct Sow April 4 Apr 4 โ€“ Apr 25
Harvest June 6 Jun 6 โ€“ Jul 25
Fall Sowing August 11 Aug 11 โ€“ Aug 25

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Transplant Outdoors Direct Sow
May โ€”
June Harvest
July Harvest
August Fall Sowing
September โ€”
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 6b

๐Ÿ“† Growing Season

185 days in Russell County

Growing Tips for Borage in Russell County

Direct sow Borage outdoors after April 18 in Russell 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 Russell County, KY?

Russell County is in Zone 6b with an average last frost of April 18. Plan your Borage planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Russell County, KY?

Russell County, Kentucky is in USDA Hardiness Zone 6b. The average last spring frost is April 18 and first fall frost is October 20.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Russell County gardeners in Zone 6b 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 Russell County, KY. Local conditions may vary. Last updated: April 2026.