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When to Plant Borage in Whiteside County, IL

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.

Whiteside County, Illinois is in USDA Zone 5a. The average last spring frost is April 16 and the first fall frost is October 16, giving you a growing season of approximately 183 days.

At an elevation of 682 feet, Whiteside County receives approximately 30.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Borage to ensure they mature before fall.

Whiteside County, IL (Zone 5a) Moderate season
183 days
Last Spring Frost April 16
183 growing days
First Fall Frost October 16

Whiteside County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (86 days to spare)
Start indoors: Mar 6 Transplant: Apr 3 🍅 Harvest: May 29 – Jul 17
Recommended (50%) ✓ Fits season (85 days to spare)
Start indoors: Mar 12 Transplant: Apr 9 🍅 Harvest: Jun 4 – Jul 23
Safe Start (90%) ✓ Fits season (87 days to spare)
Start indoors: Mar 28 Transplant: Apr 25 🍅 Harvest: Jun 20 – Aug 8

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 Whiteside County

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

Soil pH

Your soil pH (5.9โ€“6.7) overlaps with Borage's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (4.0%). 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 183-day season

Sow every 5.7 weeks. Last sowing by Aug 17 to harvest before frost.

For a dedicated fall crop, sow by Aug 07.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Borage needs ~715 GDD — county provides 2,379 GDD Excellent fit

Borage Planting Timeline โ€” Whiteside County, IL

Borage Planting Calendar

Activity When Date Range
Start Indoors March 12 Mar 12 โ€“ Mar 26
Transplant Outdoors April 9 Apr 9 โ€“ Apr 23
Direct Sow April 2 Apr 2 โ€“ Apr 23
Fall Sowing August 7 Aug 7 โ€“ Aug 21
Harvest June 4 Jun 4 โ€“ Jul 23

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 5a

๐Ÿ“† Growing Season

183 days in Whiteside County

Growing Tips for Borage in Whiteside County

Direct sow Borage outdoors after April 16 in Whiteside 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Borage in Whiteside County, IL?

Whiteside County is in Zone 5a with an average last frost of April 16. Plan your Borage planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Whiteside County, IL?

Whiteside County, Illinois is in USDA Hardiness Zone 5a. The average last spring frost is April 16 and first fall frost is October 16.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Whiteside County gardeners in Zone 5a 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 Whiteside County, IL. Local conditions may vary. Last updated: April 2026.