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When to Plant Lavender in Sumner County, KS

Sumner County, Kansas Zone 7a May

Sumner County, Kansas gardeners: here's your May plan

Each item below is timed to Sumner County, Kansas's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 11
Avg. first frost October 26
Soil temp (4") 64°F
Watering Low
Pest pressure Low
Daylight 14 hrs

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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.

Sumner County, Kansas is in USDA Zone 7a. The average last spring frost is April 11 and the first fall frost is October 26, giving you a growing season of approximately 198 days.

At an elevation of 637 feet, Sumner County receives approximately 29 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Lavender during the growing season.

Sumner County, KS (Zone 7a) Moderate season
198 days
Last Spring Frost April 11
198 growing days
First Fall Frost October 26
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Sumner County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 12 🍅 Harvest: Jul 12 – Nov 22
Recommended (50%) ✗ May not fit
Transplant: Apr 18 🍅 Harvest: Jul 18 – Nov 28
Safe Start (90%) ✗ May not fit
Transplant: May 2 🍅 Harvest: Aug 1 – Dec 12

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 Sumner County

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

Soil pH

Your soil pH (6.4–7.8) overlaps with Lavender's range (6.5–8.0), though not a perfect match.

Soil Texture

The loam soil in Sumner County is excellent for Lavender — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.6%). Annual compost additions will help Lavender.

How to Plant Lavender

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

Plant Water Budget

Plant needs
0.3″/week
Rainfall provides
0.6″/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 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 0.7" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 1.3" 3" 0" ✅ Rainfall sufficient
May 1.3" 4.4" 0" ✅ Rainfall sufficient
Jun 1.3" 4.2" 0" ✅ Rainfall sufficient
Jul 1.3" 3.4" 0" ✅ Rainfall sufficient
Aug 1.3" 4" 0" ✅ Rainfall sufficient
Sep 1.3" 3" 0" ✅ Rainfall sufficient
Oct 1.3" 1.7" 0" ✅ Rainfall sufficient
Nov 1.1" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Sumner County). Supplement amounts are based on average rainfall — 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" — 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.

Lavender needs ~1,994 GDD — county provides 2,722 GDD Excellent fit

Lavender Planting Timeline — Sumner County, KS

Lavender Planting Calendar

Activity When Date Range
Transplant Outdoors April 18 Apr 18 – May 2
Harvest July 18 Jul 18 – Nov 28

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 Harvest
November Harvest
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.3"/week · Natural rainfall sufficient

📅 Days to Maturity

90–200 days

🧪 Soil pH

Needs 6.5–8 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

198 days in Sumner County

Growing Tips for Lavender in Sumner County

Direct sow Lavender outdoors after April 11 in Sumner County when soil has warmed and frost danger has passed.

Your 198.0-day growing season in Sumner 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 Sumner County, KS?

Sumner County is in Zone 7a with an average last frost of April 11. Plan your Lavender planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sumner County, KS?

Sumner County, Kansas is in USDA Hardiness Zone 7a. The average last spring frost is April 11 and first fall frost is October 26.

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Your Sumner County Garden Planner — Free

A 24-page printable planner built for Sumner 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.

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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 Sumner County, KS. 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.