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When to Plant Lavender in Bon Homme County, SD

Lavender
Bon Homme County, South Dakota Zone 5a June

Your June gardening checklist

Each item below is timed to Bon Homme County, South Dakota's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 1
Avg. first frost October 6
Soil temp (4") 65°F
Watering Low
Pest pressure High
Daylight 15.2 hrs
July prep starts now
  • Starting indoors: lavender
  • First harvests: lavender

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Lavender (Lavandula angustifolia) is a fragrant Mediterranean sub-shrub prized for its silver-gray foliage and intensely aromatic purple flower spikes. A classic companion for roses and an unmatched pollinator magnet, lavender thrives in the exact conditions that challenge many plants: poor, rocky, alkaline soil with excellent drainage and full sun. English lavender is the most cold-hardy species, reliably perennial in Zones 5–9. Fresh or dried flowers are widely used in sachets, essential oils, culinary applications, and dried arrangements.

Bon Homme County, South Dakota is in USDA Zone 5a. The average last spring frost is May 1 and the first fall frost is October 6, giving you a growing season of approximately 158 days.

At an elevation of 771 feet, Bon Homme County receives approximately 28.1 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Lavender to ensure they mature before fall.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting Fragrant
Bon Homme County, SD (Zone 5a) Moderate season
158 days
Last Spring Frost May 1
158 growing days
First Fall Frost October 6
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Bon Homme County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.4

Drainage

Well Drained

Lavender Planting Risk Windows

Early Start (70% safe) ✓ Fits season (28 days to spare)
Start indoors: Feb 13 Transplant: May 15 🌸 Bloom: Jul 24 – Sep 4
Recommended (50%) ✓ Fits season (25 days to spare)
Start indoors: Feb 20 Transplant: May 22 🌸 Bloom: Jul 31 – Sep 11
Safe Start (90%) ✓ Fits season (22 days to spare)
Start indoors: Mar 5 Transplant: Jun 4 🌸 Bloom: Aug 13 – Sep 24

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 Bon Homme County

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

Soil pH

Your soil pH (6.4–7.4) overlaps with Lavender's range (6.5–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — Lavender will thrive.

How to Plant Lavender

0.5"
Planting Depth
18"
Between Plants
24"
Between Rows

Lavender Water Budget

Plant needs
0.3″/week
Rainfall provides
0.8″/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 0.9" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 2.8" 0" ❄️ Dormant
May 1.3" 4" 0" ✅ Rainfall sufficient
Jun 1.3" 4.5" 0" ✅ Rainfall sufficient
Jul 1.3" 3.8" 0" ✅ Rainfall sufficient
Aug 1.3" 3.7" 0" ✅ Rainfall sufficient
Sep 1.3" 2.3" 0" ✅ Rainfall sufficient
Oct 1.3" 1.8" 0" ✅ Rainfall sufficient
Nov 1.1" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Bon Homme 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 ~1,208 GDD — county provides 1,817 GDD Excellent fit

Lavender Planting Timeline — Bon Homme County, SD

Lavender Planting Calendar

Activity When Date Range
Start Indoors February 20 Feb 20 – Mar 6
Transplant Outdoors May 22 May 22 – Jun 5
Bloom July 31 Jul 31 – Sep 11

Plant 0.5" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
April
May Transplant Outdoors
June Transplant Outdoors
July Bloom
August Bloom
September Bloom
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.3"/week · Natural rainfall sufficient

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

158 days in Bon Homme County

Growing Tips for Lavender in Bon Homme County

Direct sow Lavender outdoors after May 01 in Bon Homme County when soil has warmed and frost danger has passed.

General growing tips

The single most important requirement for lavender success is excellent drainage — it will rot in heavy clay or wet winter soils before cold alone kills it. Amend with coarse sand or fine gravel if needed; raised beds work well in Zones 5–6. Start from rooted cuttings or transplants rather than seed for named cultivars. Transplant after last frost when soil is reliably warm (55°F+). Avoid rich or overly moist soils. Prune lightly after each flush of bloom, but never cut into old wood below the green growth zone — it will not regenerate from leafless woody stems. In Zones 5–6, mulch lightly with gravel (not bark/organic material which traps moisture) around the crown for winter protection. Year 2+ plants develop into full, mature shrubs with the most prolific bloom.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lavender in Bon Homme County, SD?

Bon Homme County is in Zone 5a with an average last frost of May 1. Plan your Lavender planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bon Homme County, SD?

Bon Homme County, South Dakota is in USDA Hardiness Zone 5a. The average last spring frost is May 1 and first fall frost is October 6.

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Your Bon Homme County Garden Planner — Free

A 22-page printable planner built for Bon Homme County (Zone 5a). 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 Bon Homme County, SD. 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.