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When to Plant Lavender in Johnson County, IN

Lavender is a fragrant perennial herb with silvery foliage and purple flower spikes. It is prized for its essential oils, culinary uses, and ornamental beauty.

Johnson County, Indiana is in USDA Zone 6a. The average last spring frost is April 12 and the first fall frost is October 22, giving you a growing season of approximately 193 days.

At an elevation of 1,324 feet, Johnson County receives approximately 36.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Lavender during the growing season.

Johnson County, IN (Zone 6a) Moderate season
193 days
Last Spring Frost April 12
193 growing days
First Fall Frost October 22

Johnson County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 14 🍅 Harvest: Jul 14 – Oct 27
Recommended (50%) ✗ May not fit
Transplant: Apr 19 🍅 Harvest: Jul 19 – Nov 1
Safe Start (90%) ✗ May not fit
Transplant: May 6 🍅 Harvest: Aug 5 – Nov 18

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 Johnson County

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

Soil pH

Your soil pH (6.2โ€“7.0) overlaps with Lavender's range (6.5โ€“8.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.1%) โ€” Lavender will thrive.

How to Plant Lavender

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

Plant Water Budget

Plant needs
0.3″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Lavender

Lavender needs approximately 0.3 inches of water per week (1.3" per month). Here's how your county's rainfall compares month by month.

Month Lavender Needs Rainfall You Supplement Action
Jan โ€” 1.7" 0" โ„๏ธ Dormant
Feb โ€” 1.6" 0" โ„๏ธ Dormant
Mar โ€” 2.3" 0" โ„๏ธ Dormant
Apr 1.3" 3.4" 0" โœ… Rainfall sufficient
May 1.3" 4.6" 0" โœ… Rainfall sufficient
Jun 1.3" 4.1" 0" โœ… Rainfall sufficient
Jul 1.3" 4.4" 0" โœ… Rainfall sufficient
Aug 1.3" 4" 0" โœ… Rainfall sufficient
Sep 1.3" 3.1" 0" โœ… Rainfall sufficient
Oct 1.3" 2.9" 0" โœ… Rainfall sufficient
Nov โ€” 2.2" 0" โ„๏ธ Dormant
Dec โ€” 2.2" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Johnson County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Lavender 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" โ€” every day above 50ยฐF 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.

Lavender needs ~2,538 GDD — county provides 3,377 GDD Excellent fit

Lavender Planting Timeline โ€” Johnson County, IN

Lavender Planting Calendar

Activity When Date Range
Transplant Outdoors April 19 Apr 19 โ€“ May 3
Harvest July 19 Jul 19 โ€“ Nov 1

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 Harvest
August Harvest
September Harvest
October Harvest
November Harvest
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.3"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

90โ€“200 days

๐Ÿงช Soil pH

Needs 6.5โ€“8 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

193 days in Johnson County

Growing Tips for Lavender in Johnson County

Direct sow Lavender outdoors after April 12 in Johnson County when soil has warmed and frost danger has passed.

Your 193.0-day growing season in Johnson County is tight for Lavender (90.0-200.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Plant in well-drained, sandy soil. Avoid heavy mulching around the crown. Prune after flowering but do not cut into old wood. Lavender resents wet winter conditions.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lavender in Johnson County, IN?

Johnson County is in Zone 6a with an average last frost of April 12. Plan your Lavender planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Johnson County, IN?

Johnson County, Indiana is in USDA Hardiness Zone 6a. The average last spring frost is April 12 and first fall frost is October 22.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Johnson County gardeners in Zone 6a 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 Johnson County, IN. Local conditions may vary. Last updated: April 2026.