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When to Plant Borage in Allen County, IN

Allen County, Indiana Zone 6a May

Your May planting checklist for Allen County, Indiana

May is a pivotal month for Allen County, Indiana gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 25
Avg. first frost October 21
Soil temp (4") 57°F
Watering Low
Pest pressure Low
Daylight 14.3 hrs
  1. Start borage under lights

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

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.

Allen County, Indiana is in USDA Zone 6a. The average last spring frost is April 25 and the first fall frost is October 21, giving you a growing season of approximately 179 days.

At an elevation of 721 feet, Allen County receives approximately 38.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Borage during the growing season.

Allen County, IN (Zone 6a) Moderate season
179 days
Last Spring Frost April 25
179 growing days
First Fall Frost October 21
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Allen County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (82 days to spare)
Start indoors: Mar 12 Transplant: Apr 9 🍅 Harvest: Jun 4 – Jul 23
Recommended (50%) ✓ Fits season (81 days to spare)
Start indoors: Mar 21 Transplant: Apr 18 🍅 Harvest: Jun 13 – Aug 1
Safe Start (90%) ✓ Fits season (79 days to spare)
Start indoors: Apr 2 Transplant: Apr 30 🍅 Harvest: Jun 25 – Aug 13

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 Allen County

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

Soil pH

Your soil pH (6.0–7.0) is within Borage's preferred range (6.0–7.0).

Soil Texture

The silt loam soil in Allen 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 10 weeks before your first frost date for a fall harvest.

Succession Planting Borage

4
successive plantings in your 179-day season

Sow every 5.7 weeks. Last sowing by Aug 22 to harvest before frost.

For a dedicated fall crop, sow by Aug 12.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/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 1.6" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 2.2" 3.4" 0" ✅ Rainfall sufficient
May 2.2" 4" 0" ✅ Rainfall sufficient
Jun 2.2" 4.9" 0" ✅ Rainfall sufficient
Jul 2.2" 4.1" 0" ✅ Rainfall sufficient
Aug 2.2" 4.6" 0" ✅ Rainfall sufficient
Sep 2.2" 3.8" 0" ✅ Rainfall sufficient
Oct 2.2" 2.8" 0" ✅ Rainfall sufficient
Nov 2.9" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Allen 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 ~756 GDD — county provides 2,461 GDD Excellent fit

Borage Planting Timeline — Allen County, IN

Borage Planting Calendar

Activity When Date Range
Start Indoors March 21 Mar 21 – Apr 4
Transplant Outdoors April 18 Apr 18 – May 2
Direct Sow April 11 Apr 11 – May 2
Harvest June 13 Jun 13 – Aug 1
Fall Sowing August 12 Aug 12 – Aug 26

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 6a

📆 Growing Season

179 days in Allen County

Growing Tips for Borage in Allen County

Direct sow Borage outdoors after April 25 in Allen 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 Allen County, IN?

Allen County is in Zone 6a with an average last frost of April 25. Plan your Borage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Allen County, IN?

Allen County, Indiana is in USDA Hardiness Zone 6a. The average last spring frost is April 25 and first fall frost is October 21.

🌱

Your Allen County Garden Planner — Free

A 24-page printable planner built for Allen County (Zone 6a). 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 Allen County, IN. 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.