When to plant Hyssop in Monroe County, IL
In Monroe County, Hyssop is a single-season spring crop — there's no second fall window. Plant April 21–May 5 for an 70–90-day harvest, finishing well before the October 24 first frost.
When to Plant Hyssop in Monroe 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.
Monroe County, Illinois is in USDA Zone 7a. The average last spring frost is April 14 and the first fall frost is October 24, giving you a growing season of approximately 193 days.
At an elevation of 1,278 feet, Monroe County receives approximately 34.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Hyssop during the growing season.
Monroe County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.8
Drainage
Well Drained
Monthly Watering Guide for Hyssop
Hyssop needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Hyssop Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.2" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.7" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| May | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Jun | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Jul | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Aug | 4.3" | 4" | 0.3" | 💧 Light watering |
| Sep | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Oct | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Nov | — | 2.4" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Monroe County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Hyssop Planting Timeline — Monroe 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
| Month | Activities |
|---|---|
| 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 7a
📆 Growing Season
193 days in Monroe County
Growing Tips for Monroe 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
Check more plant combinations with our Companion Planting Checker →
Hyssop in Other Locations
Frequently Asked Questions
When should I plant Hyssop in Monroe County, IL?
Monroe County is in Zone 7a 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 Monroe County, IL?
Monroe County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 14 and first fall frost is October 24.
When should I plant Hyssop in Monroe County, IL?
In Monroe County, IL, plant Hyssop after the last frost (around April 14) and before the first frost (around October 24). Best results when soil holds above 50°F.
What growing zone is Monroe County, IL for Hyssop?
Monroe County sits in USDA Zone 7a. Hyssop grows reliably in zones 3a through 9b, so it's a good fit here.
Can Hyssop grow in Monroe County's climate?
Yes — Hyssop grows well in Monroe County's temperate climate. Monroe County averages a 193-day frost-free season, with last frost around April 14 and first frost around October 24.
Your Monroe County Garden Planner — Free
A 22-page printable planner built for Monroe County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.