Blog

When to plant Hyssop in Whiteside County, IL

Plant Hyssop in Whiteside County, between April 23 and May 7 — the only viable window. Zone 5b's short season (183 frost-free days) rules out a fall crop.

When to Plant Hyssop in Whiteside 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.

Whiteside County, Illinois is in USDA Zone 5b. 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 84°F, so choose short-season varieties of Hyssop to ensure they mature before fall.

Whiteside County, IL (Zone 5b) 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

6.0-7.0

Drainage

Well Drained

Hyssop Planting Timeline — Whiteside County, IL

Hyssop Planting Calendar

Activity When Date Range
Transplant Outdoors April 23 Apr 23 – May 7
Harvest July 2 Jul 2 – Sep 3

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Transplant Outdoors
May Transplant Outdoors
June
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 5b

📆 Growing Season

183 days in Whiteside County

Growing Tips for Whiteside 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 Whiteside County, IL?

Whiteside County is in Zone 5b with an average last frost of April 16. Plan your Hyssop planting based on this frost date — see the calendar above for exact timing.

What planting zone is Whiteside County, IL?

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

When should I plant Hyssop in Whiteside County, IL?

In Whiteside County, IL, plant Hyssop after the last frost (around April 16) and before the first frost (around October 16). Best results when soil holds above 50°F.

What growing zone is Whiteside County, IL for Hyssop?

Whiteside County sits in USDA Zone 5b. Hyssop grows reliably in zones 3a through 9b, so it's a good fit here.

Can Hyssop grow in Whiteside County's climate?

Yes — Hyssop grows well in Whiteside County's temperate climate. Whiteside County averages a 183-day frost-free season, with last frost around April 16 and first frost around October 16.

🌱

Your Whiteside County Garden Planner — Free

A 22-page printable planner built for Whiteside County (Zone 5b). 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 Whiteside County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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