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When to Plant Lupine in Cable, Wisconsin (54821)

Location

Cable, Wisconsin

ZIP Code

54821

USDA Zone

4a

Last Frost

Friday, May 15, 2026

📅 Your 2026 Planting Dates

Direct Sow Outdoors

Friday, April 17, 2026

Based on last frost Friday, May 15, 2026 · Zone 4a

Pro tip: Sow Lupine directly outdoors 4 weeks before your last frost date.

🌿 Plant Details

Scientific Name Lupinus polyphyllus
Days to Maturity 365 days
Mature Height 24-48"
Spread 24"

☀️ Growing Requirements

☀️

Sun

Full Sun to Partial Shade

💧

Water

Moderate (1 inch/week)

↔️

Spacing

18" apart

🌱

Planting Depth

0.5" deep

Seeds typically germinate in 14-21 days

Ready to Plant Lupine in Cable?

Get your seeds now so they're ready by Friday, April 17, 2026.

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🤝 Good Companions

CarrotBrassicasCorn

⚠️ Avoid Planting Near

Fennel
🤝

Full Companion Planting Guide for Lupine

See which plants help Lupine thrive, which to keep away, and raised bed layout tips →

🛠️ Supplies You'll Need

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🌾 Seed Saving Guide

🟢 Easy
✅ Open-pollinated — seeds grow true to parent

When to Harvest Seed

Allow seed pods to dry on the plant — pods will turn black and begin to twist when fully ripe.

Processing

Collect before pods explode and fling seeds. Shell pods, dry seeds 1 week.

Seed Viability

Up to 3 years when stored cool, dark, and dry.

Pro Tip

Lupine seeds have a hard coat — nick with sandpaper or soak 24 hours before sowing to improve germination.

🪴

Raised Bed Planting Guides

A 4×8 bed fits 14 plants of Lupine. See plant counts, spacing grids, and companion pairings for every bed size →

Frequently Asked Questions

When should I plant Lupine in Cable, Wisconsin? +

In Cable (Zone 4a), direct sow Lupine outdoors around Friday, April 17, 2026.

What is the last frost date for Cable, Wisconsin? +

The average last spring frost date for Cable, Wisconsin (ZIP 54821) is around Friday, May 15, 2026. This is based on NOAA climate normals for USDA Zone 4a.

How long does Lupine take to grow? +

Lupine typically matures in about 365 days from direct sowing. In Cable, that means you can expect harvest around Friday, April 17, 2026 plus 365 days.

Should I start Lupine indoors or direct sow in Wisconsin? +

Lupine does best when direct sown outdoors. In Cable, sow directly around Friday, April 17, 2026.

Other Plants for Cable

Growing Lupine in Zone 4a

Lupine (Lupinus polyphyllus) is a popular garden vegetable. In Cable, Wisconsin, which is in USDA Hardiness Zone 4a, you should direct sow seeds around Friday, April 17, 2026.

Your average last frost date is Friday, May 15, 2026. Lupine grows well when direct sown, as it doesn't transplant well or germinates quickly outdoors.