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When to plant Lupine in Mapleton, IL

In Mapleton, plant Lupine in spring between April 30 and May 21, once soil temps hold above 50°F. Mapleton'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 75–100 days before the first frost on October 12.

When to Plant Lupine in Mapleton, IL

Peoria County, Illinois Zone 6a July

This month in Peoria County, Illinois

July rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Peoria County, Illinois.

Avg. last frost April 23
Avg. first frost October 12
Soil temp (4") 76°F
Watering Moderate
Pest pressure High
Daylight 14.7 hrs
  1. Bring in the lupine

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

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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.

Mapleton, Illinois is in USDA Zone 6a. The average last spring frost is April 23 and the first fall frost is October 12, giving you a growing season of approximately 172 days.

At an elevation of 884 feet, Peoria County receives approximately 33 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Lupine during the growing season.

Perennial Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Mapleton, IL (Zone 6a) Moderate season
172 days
Last Spring Frost April 23
172 growing days
First Fall Frost October 12

Mapleton Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7

Drainage

Well Drained

Lupine Planting Risk Windows

Early Start (70% safe) ✓ Fits season (76 days to spare)
Start indoors: Feb 13 Transplant: Apr 24 🌸 Bloom: Jun 19 – Jul 24
Recommended (50%) ✓ Fits season (74 days to spare)
Start indoors: Feb 19 Transplant: Apr 30 🌸 Bloom: Jun 25 – Jul 30
Safe Start (90%) ✓ Fits season (75 days to spare)
Start indoors: Mar 6 Transplant: May 15 🌸 Bloom: Jul 10 – Aug 14

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 Mapleton

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

Soil pH

Your soil pH (6.1–7.0) is within Lupine's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.7%) — 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 172-day season

Sow every 8.6 weeks. Last sowing by Jul 04 to harvest before frost.

Lupine Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 297 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 1.4" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 4.3" 3.5" 0.8" 💧 Light watering
May 4.3" 4.2" 0.1" 💧 Light watering
Jun 4.3" 3.9" 0.4" 💧 Light watering
Jul 4.3" 3.2" 1.1" 💧 Light watering
Aug 4.3" 3.4" 0.9" 💧 Light watering
Sep 4.3" 3.2" 1.1" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 1.9" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Peoria 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 ~1,269 GDD — county provides 2,494 GDD Excellent fit

Lupine Planting Timeline — Mapleton, IL

Lupine Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 – Mar 5
Transplant Outdoors April 30 Apr 30 – May 14
Direct Sow April 30 Apr 30 – May 21
Bloom June 25 Jun 25 – Jul 30

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
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 · Only during dry spells

📅 Days to Maturity

75–100 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

172 days in Peoria County

Growing Tips for Lupine in Mapleton

Direct sow Lupine outdoors after April 23 in Peoria 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 →

When should I plant Lupine in Mapleton, IL?

In Mapleton, IL, plant Lupine after the last frost (around April 23) and before the first frost (around October 12). Best results when soil holds above 50°F.

What growing zone is Mapleton, IL for Lupine?

Mapleton sits in USDA Zone 6a. Lupine grows reliably in zones 3a through 8b, so it's a good fit here.

Can Lupine grow in Mapleton's climate?

Yes — Lupine grows well in Mapleton's temperate climate. Mapleton averages a 172-day frost-free season, with last frost around April 23 and first frost around October 12.

🌱

Your Peoria County Garden Planner — Free

A 22-page printable planner built for Peoria 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.

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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 Peoria County, IL. Local conditions may vary. Last updated: July 2026.