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When to plant Lupine in Ogle County County,

In Ogle County County, plant Lupine in spring between May 7 and May 28, once soil temps hold above 50°F. Ogle County County's last frost averages April 23, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between and — roughly 100 days before the first frost on October 13.

When to Plant Lupine in Ogle County, IL

Ogle County, Illinois Zone 5b June

Your June planting checklist for Ogle County, Illinois

Your garden in Ogle County, Illinois is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost April 23
Avg. first frost October 13
Soil temp (4") 69°F
Watering Low
Pest pressure High
Daylight 15 hrs
  1. Indoor seed-starting week for lupine

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

Looking ahead to July
  • 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.

Ogle County, Illinois is in USDA Zone 5b. The average last spring frost is April 23 and the first fall frost is October 13, giving you a growing season of approximately 173 days.

At an elevation of 890 feet, Ogle County receives approximately 39.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Lupine during the growing season.

Perennial Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Ogle County, IL (Zone 5b) Moderate season
173 days
Last Spring Frost April 23
173 growing days
First Fall Frost October 13

Ogle County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.9

Drainage

Well Drained

Lupine Planting Risk Windows

Early Start (70% safe) ✓ Fits season (62 days to spare)
Start indoors: Feb 14 Transplant: May 2 🌸 Bloom: Jun 27 – Aug 8
Recommended (50%) ✓ Fits season (61 days to spare)
Start indoors: Feb 19 Transplant: May 7 🌸 Bloom: Jul 2 – Aug 13
Safe Start (90%) ✓ Fits season (64 days to spare)
Start indoors: Mar 2 Transplant: May 18 🌸 Bloom: Jul 13 – Aug 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 Ogle County

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

Soil pH

Your soil pH (5.9–6.9) is within Lupine's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — 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 173-day season

Sow every 8.6 weeks. Last sowing by Jul 05 to harvest before frost.

Lupine Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 52 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 1.9" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 4.3" 3.9" 0.4" 💧 Light watering
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 5" 0" ✅ Rainfall sufficient
Jul 4.3" 5" 0" ✅ Rainfall sufficient
Aug 4.3" 4" 0.3" 💧 Light watering
Sep 4.3" 3.9" 0.4" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 2.5" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Ogle 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 ~1,203 GDD — county provides 2,378 GDD Excellent fit

Lupine Planting Timeline — Ogle County, IL

Lupine Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 – Mar 5
Transplant Outdoors May 7 May 7 – May 21
Direct Sow May 7 May 7 – May 28
Bloom July 2 Jul 2 – Aug 13

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

75–100 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 5b

📆 Growing Season

173 days in Ogle County

Growing Tips for Lupine in Ogle County

Direct sow Lupine outdoors after April 23 in Ogle 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 Ogle County, IL?

Ogle County is in Zone 5b with an average last frost of April 23. Plan your Lupine planting based on this frost date — see the calendar above for exact timing.

What planting zone is Ogle County, IL?

Ogle County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 23 and first fall frost is October 13.

When should I plant Lupine in Ogle County County, ?

In Ogle County County, , plant Lupine after the last frost (around April 23) and before the first frost (around October 13). Best results when soil holds above 50°F.

What growing zone is Ogle County County, for Lupine?

Ogle County County sits in USDA Zone 5b. Lupine grows reliably in zones 3a through 8b, so it's a good fit here.

Can Lupine grow in Ogle County County's climate?

Yes — Lupine grows well in Ogle County County's temperate climate. Ogle County County averages a 173-day frost-free season, with last frost around April 23 and first frost around October 13.

🌱

Your Ogle County Garden Planner — Free

A 22-page printable planner built for Ogle 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 Ogle County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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