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When to Plant Valerian in Ogle County, IL

Valerian is a tall perennial herb with fragrant white or pink flower clusters, valued for its root which is used as a natural sleep aid. It attracts pollinators and earthworms.

Ogle County, Illinois is in USDA Zone 5a. The average last spring frost is April 23 and the first fall frost is October 13, giving you a growing season of approximately 173 days.

At an elevation of 890 feet, Ogle County receives approximately 39.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Valerian during the growing season.

Ogle County, IL (Zone 5a) Moderate season
173 days
Last Spring Frost April 23
173 growing days
First Fall Frost October 13

Ogle County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 25 🍅 Harvest: Aug 29 – Oct 10
Recommended (50%) ✗ May not fit
Transplant: Apr 30 🍅 Harvest: Sep 3 – Oct 15
Safe Start (90%) ✓ Fits season (1 days to spare)
Transplant: May 11 🍅 Harvest: Sep 14 – Oct 26

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 Ogle County

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

Soil pH

Your soil pH (5.9โ€“6.9) is within Valerian's preferred range (5.5โ€“7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) โ€” Valerian will thrive.

How to Plant Valerian

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 52 gal / 100 sq ft
Valerian needs ~2,062 GDD — county provides 2,378 GDD Good fit

Valerian Planting Timeline โ€” Ogle County, IL

Valerian Planting Calendar

Activity When Date Range
Transplant Outdoors April 30 Apr 30 โ€“ May 14
Harvest September 3 Sep 3 โ€“ Oct 15

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Transplant Outdoors
May Transplant Outdoors
June โ€”
July โ€”
August โ€”
September Harvest
October Harvest
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

120โ€“180 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

173 days in Ogle County

Growing Tips for Valerian in Ogle County

Direct sow Valerian outdoors after April 23 in Ogle County when soil has warmed and frost danger has passed.

Your 173.0-day growing season in Ogle County is tight for Valerian (120.0-180.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Start seeds indoors and transplant after last frost. Harvest roots in fall of the second year. Deadhead flowers unless you want self-seeding. Cats are attracted to valerian root.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Valerian in Ogle County, IL?

Ogle County is in Zone 5a with an average last frost of April 23. Plan your Valerian planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Ogle County, IL?

Ogle County, Illinois is in USDA Hardiness Zone 5a. The average last spring frost is April 23 and first fall frost is October 13.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Ogle County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

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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 Ogle County, IL. Local conditions may vary. Last updated: April 2026.