Blog

When to plant Hyssop in Clay County, IL

In Clay County, Hyssop is a spring-only crop. Plant April 21–May 5 once soil hits 50°F.

When to Plant Hyssop in Clay County, IL

Hyssop is a semi-evergreen perennial herb with intense blue flower spikes that attract bees and butterflies. It has a minty, slightly bitter flavor used in liqueurs and teas.

Clay County, Illinois is in USDA Zone 6b. The average last spring frost is April 14 and the first fall frost is October 17, giving you a growing season of approximately 186 days.

At an elevation of 1,105 feet, Clay County receives approximately 34.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Hyssop during the growing season.

Clay County, IL (Zone 6b) Moderate season
186 days
Last Spring Frost April 14
186 growing days
First Fall Frost October 17

Clay County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Hyssop Planting Timeline — Clay County, IL

Hyssop Planting Calendar

Activity When Date Range
Transplant Outdoors April 21 Apr 21 – May 5
Harvest June 30 Jun 30 – Sep 1

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–8 · Your soil: N/A

🗺️ USDA Zone

Zone 6b

📆 Growing Season

186 days in Clay County

Growing Tips for Clay County

Start seeds indoors or direct sow in spring. Prune back in early spring to encourage bushy growth. Hyssop is drought-tolerant once established and thrives in poor soil.

Companion Planting

Good Companions

Avoid Planting Near

  • Radish

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Hyssop in Clay County, IL?

Clay County is in Zone 6b with an average last frost of April 14. Plan your Hyssop planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clay County, IL?

Clay County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 14 and first fall frost is October 17.

When should I plant Hyssop in Clay County, IL?

In Clay County, IL, plant Hyssop after the last frost (around April 14) and before the first frost (around October 17). Best results when soil holds above 50°F.

What growing zone is Clay County, IL for Hyssop?

Clay County sits in USDA Zone 6b. Hyssop grows reliably in zones 3a through 9b, so it's a good fit here.

Can Hyssop grow in Clay County's climate?

Yes — Hyssop grows well in Clay County's temperate climate. Clay County averages a 186-day frost-free season, with last frost around April 14 and first frost around October 17.

🌱

Your Clay County Garden Planner — Free

A 22-page printable planner built for Clay County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Clay County, IL. Local conditions may vary. Last updated: August 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.