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When to Plant Lupine in Clark County, OH

Clark County, Ohio Zone 6a June

Clark County, Ohio gardeners: here's your June plan

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Clark County, Ohio.

Avg. last frost April 18
Avg. first frost October 21
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 14.8 hrs
  1. Sow lupine in trays indoors

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

  2. Harvest lupine as they ripen

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Coming up in July — start thinking about
  • First harvests: lupine

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Wild Lupine (Lupinus perennis) is a stunning native perennial of eastern North America, producing tall, densely packed spikes of pea-like flowers in deep blue-purple — the classic wildflower of sandy pine barrens and open woodlands. Russell Hybrid Lupins extend the color range to pink, red, yellow, and bicolors and produce larger flower spikes, making them popular cottage garden perennials. The palmately compound foliage is attractive throughout the season. Wild lupine is the sole larval host plant of the federally endangered Karner Blue butterfly, making it a high-value native planting. Seeds are toxic if ingested. Nitrogen-fixing roots improve surrounding soil over time.

Clark County, Ohio is in USDA Zone 6a. The average last spring frost is April 18 and the first fall frost is October 21, giving you a growing season of approximately 186 days.

At an elevation of 721 feet, Clark County receives approximately 34.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Lupine during the growing season.

Perennial Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Clark County, OH (Zone 6a) Moderate season
186 days
Last Spring Frost April 18
186 growing days
First Fall Frost October 21

Clark County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.1

Drainage

Well Drained

Lupine Planting Risk Windows

Early Start (70% safe) ✓ Fits season (90 days to spare)
Start indoors: Feb 7 Transplant: Apr 18 🌸 Bloom: Jun 13 – Jul 18
Recommended (50%) ✓ Fits season (88 days to spare)
Start indoors: Feb 14 Transplant: Apr 25 🌸 Bloom: Jun 20 – Jul 25
Safe Start (90%) ✓ Fits season (80 days to spare)
Start indoors: Mar 7 Transplant: May 16 🌸 Bloom: Jul 11 – Aug 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 Clark County

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

Soil pH

Your soil pH (6.0–7.1) overlaps with Lupine's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Lupine.

Organic Matter

Organic matter is excellent (4.3%) — Lupine will thrive.

How to Plant Lupine

0.3"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Lupine

2
successive plantings in your 186-day season

Sow every 8.6 weeks. Last sowing by Jul 13 to harvest before frost.

Lupine Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 851 gal / 100 sq ft

Monthly Watering Guide for Lupine

Lupine needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Lupine Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 4.3" 3.1" 1.2" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 4" 0.3" 💧 Light watering
Jul 4.3" 4.3" 0" ✅ Rainfall sufficient
Aug 4.3" 3.3" 1" 💧 Light watering
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 2.2" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

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

Lupine 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.

Lupine needs ~1,400 GDD — county provides 2,976 GDD Excellent fit

Lupine Planting Timeline — Clark County, OH

Lupine Planting Calendar

Activity When Date Range
Start Indoors February 14 Feb 14 – Feb 28
Transplant Outdoors April 25 Apr 25 – May 9
Direct Sow April 25 Apr 25 – May 16
Bloom June 20 Jun 20 – Jul 25

Plant 0.3" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

75–100 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

186 days in Clark County

Growing Tips for Lupine in Clark County

Direct sow Lupine outdoors after April 18 in Clark County when soil has warmed and frost danger has passed.

Common pests for Lupine in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Scarify seeds before planting — nick with a file or sandpaper, or soak in warm water for 24 hours — to improve germination. Start in biodegradable pots (peat or paper) 8–10 weeks before last frost to avoid disturbing the taproot at transplant. Direct sowing is equally effective if done fresh in fall (natural stratification and scarification over winter). Transplant or direct-sow after last frost into well-drained, lean soil. Lupines prefer cool, moist springs and decline in summer heat and humidity. They are relatively short-lived in warm zones (treat as biennial in Zones 7–8). Do not over-fertilize — nitrogen-fixers thrive in lean soil. Deadhead after bloom to extend season; allow some pods to mature for self-seeding. Year 2+ plants produce the largest flower spikes.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lupine in Clark County, OH?

Clark County is in Zone 6a with an average last frost of April 18. Plan your Lupine planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clark County, OH?

Clark County, Ohio is in USDA Hardiness Zone 6a. The average last spring frost is April 18 and first fall frost is October 21.

🌱

Your Clark County Garden Planner — Free

A 22-page printable planner built for Clark County (Zone 6a). 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 Clark County, OH. 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.