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When to plant Lavender in Capron, IL

In Capron, Lavender is a single-season spring crop — there's no second fall window. Plant May 14–May 28 for an 90–120-day harvest, finishing well before the October 16 first frost.

When to Plant Lavender in Capron, IL

Lavender
Boone County, Illinois Zone 5b July

This month in Boone County, Illinois

Your Boone County, Illinois garden is entering a new phase. Here's what's on the schedule for July and why each task matters now.

Avg. last frost April 23
Avg. first frost October 16
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 14.8 hrs
  1. Begin indoor sowing: lavender

    Label every cell. You will absolutely forget which is which otherwise.

  2. It's harvest week for lavender

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

A few tasks this July that'll pay off in August
  • 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.

Capron, Illinois is in USDA Zone 5b. The average last spring frost is April 23 and the first fall frost is October 16, giving you a growing season of approximately 176 days.

At an elevation of 512 feet, Boone County receives approximately 39.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°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
Capron, IL (Zone 5b) Moderate season
176 days
Last Spring Frost April 23
176 growing days
First Fall Frost October 16

Capron Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.8

Drainage

Well Drained

Lavender Planting Risk Windows

Early Start (70% safe) ✓ Fits season (37 days to spare)
Start indoors: Feb 6 Transplant: May 8 🌸 Bloom: Jul 17 – Sep 4
Recommended (50%) ✓ Fits season (36 days to spare)
Start indoors: Feb 12 Transplant: May 14 🌸 Bloom: Jul 23 – Sep 10
Safe Start (90%) ✓ Fits season (33 days to spare)
Start indoors: Mar 1 Transplant: May 31 🌸 Bloom: Aug 9 – Sep 27

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 Capron

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

Soil pH

Your soil pH (6.0–6.8) is more acidic than Lavender prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Lavender.

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Lavender.

How to Plant Lavender

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

Lavender Water Budget

Plant needs
0.3″/week
Rainfall provides
1.0″/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 1.6" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 1.3" 3.4" 0" ✅ Rainfall sufficient
May 1.3" 4.1" 0" ✅ Rainfall sufficient
Jun 1.3" 5.7" 0" ✅ Rainfall sufficient
Jul 1.3" 4.9" 0" ✅ Rainfall sufficient
Aug 1.3" 3.8" 0" ✅ Rainfall sufficient
Sep 1.3" 3.5" 0" ✅ Rainfall sufficient
Oct 1.3" 3.5" 0" ✅ Rainfall sufficient
Nov 2.9" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Boone 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 ~1,286 GDD — county provides 2,156 GDD Excellent fit

Lavender Planting Timeline — Capron, IL

Lavender Planting Calendar

Activity When Date Range
Start Indoors February 12 Feb 12 – Feb 26
Transplant Outdoors May 14 May 14 – May 28
Bloom July 23 Jul 23 – Sep 10

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

Month-by-Month Timeline

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

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: too_acidic

🗺️ USDA Zone

Zone 5b

📆 Growing Season

176 days in Boone County

Growing Tips for Lavender in Capron

Direct sow Lavender outdoors after April 23 in Boone 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 →

When should I plant Lavender in Capron, IL?

In Capron, IL, plant Lavender after the last frost (around April 23) and before the first frost (around October 16). Best results when soil holds above 50°F.

What growing zone is Capron, IL for Lavender?

Capron sits in USDA Zone 5b. Lavender grows reliably in zones 5a through 9b, so it's a good fit here.

Can Lavender grow in Capron's climate?

Yes — Lavender grows well in Capron's temperate climate. Capron averages a 176-day frost-free season, with last frost around April 23 and first frost around October 16.

🌱

Your Boone County Garden Planner — Free

A 22-page printable planner built for Boone County (Zone 5b). 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 Boone County, IL. Local conditions may vary. Last updated: July 2026.