Blog

When to Plant Hyssop in Marion County, KY

Marion County, Kentucky Zone 7a May

Marion County, Kentucky gardeners: here's your May plan

We've pulled the most time-sensitive tasks for Marion County, Kentucky this May and put them front and centre. Tackle them in order.

Avg. last frost April 13
Avg. first frost October 26
Soil temp (4") 60°F
Watering Moderate
Pest pressure Low
Daylight 14 hrs
Looking ahead to June
  • First harvests: hyssop

Instant PDF download. No spam, unsubscribe any time.

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.

Marion County, Kentucky is in USDA Zone 7a. The average last spring frost is April 13 and the first fall frost is October 26, giving you a growing season of approximately 196 days.

At an elevation of 2,021 feet, Marion County receives approximately 41.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Hyssop during the growing season.

Marion County, KY (Zone 7a) Moderate season
196 days
Last Spring Frost April 13
196 growing days
First Fall Frost October 26
Share this guide:

Marion County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (55 days to spare)
Transplant: Apr 14 🍅 Harvest: Jun 23 – Aug 25
Recommended (50%) ✓ Fits season (56 days to spare)
Transplant: Apr 20 🍅 Harvest: Jun 29 – Aug 31
Safe Start (90%) ✓ Fits season (48 days to spare)
Transplant: May 5 🍅 Harvest: Jul 14 – Sep 15

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 Marion County

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

Soil pH

Your soil pH (5.8–7.1) overlaps with Hyssop's range (6.0–8.0), though not a perfect match.

Soil Texture

The silt loam soil in Marion County is excellent for Hyssop — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Hyssop prefers dry conditions but your soil drains poorly. Use raised beds or mounded rows to prevent root rot.

Organic Matter

Organic matter is moderate (3.1%). Annual compost additions will help Hyssop.

How to Plant Hyssop

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

Succession Planting Hyssop

3
successive plantings in your 196-day season

Sow every 8 weeks. Last sowing by Jul 28 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Hyssop

Hyssop needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Hyssop Needs Rainfall You Supplement Action
Jan 3.9" 0" ❄️ Dormant
Feb 2.9" 0" ❄️ Dormant
Mar 4.2" 0" ❄️ Dormant
Apr 2.2" 3.3" 0" ✅ Rainfall sufficient
May 2.2" 3.1" 0" ✅ Rainfall sufficient
Jun 2.2" 3.8" 0" ✅ Rainfall sufficient
Jul 2.2" 4.3" 0" ✅ Rainfall sufficient
Aug 2.2" 4.1" 0" ✅ Rainfall sufficient
Sep 2.2" 3" 0" ✅ Rainfall sufficient
Oct 2.2" 2.5" 0" ✅ Rainfall sufficient
Nov 2.9" 0" ❄️ Dormant
Dec 3.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Marion County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Hyssop Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Hyssop needs ~1,460 GDD — county provides 3,577 GDD Excellent fit

Hyssop Planting Timeline — Marion County, KY

Hyssop Planting Calendar

Activity When Date Range
Transplant Outdoors April 20 Apr 20 – May 4
Harvest June 29 Jun 29 – Aug 31

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
October
November
December
Share this guide:

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–8 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

196 days in Marion County

Growing Tips for Hyssop in Marion County

Direct sow Hyssop outdoors after April 13 in Marion County when soil has warmed and frost danger has passed.

General growing tips

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 Marion County, KY?

Marion County is in Zone 7a with an average last frost of April 13. Plan your Hyssop planting based on this frost date — see the calendar above for exact timing.

What planting zone is Marion County, KY?

Marion County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 13 and first fall frost is October 26.

🌱

Your Marion County Garden Planner — Free

A 24-page printable planner built for Marion 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.

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 Marion County, KY. Local conditions may vary. Last updated: May 2026.

Sources & credits

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