📍 Eagle River, WI · Zone 4b · Last frost Tuesday, May 5, 2026
✏️ ChangeWhen to Plant Lupine in Eagle River, Wisconsin (54521)
Location
Eagle River, Wisconsin
ZIP Code
54521
USDA Zone
4b
Last Frost
Tuesday, May 5, 2026
📅 Your 2026 Planting Dates
Direct Sow Outdoors
Tuesday, April 7, 2026
Based on last frost Tuesday, May 5, 2026 · Zone 4b
Pro tip: Sow Lupine directly outdoors 4 weeks before your last frost date.
🌿 Plant Details
☀️ 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 Eagle River?
Get your seeds now so they're ready by Tuesday, April 7, 2026.
* Affiliate links — we may earn a small commission at no extra cost to you.
🤝 Good Companions
⚠️ Avoid Planting Near
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
* Affiliate links — we may earn a small commission at no extra cost to you.
🌾 Seed Saving Guide
🟢 EasyWhen 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 Eagle River, Wisconsin? +
In Eagle River (Zone 4b), direct sow Lupine outdoors around Tuesday, April 7, 2026.
What is the last frost date for Eagle River, Wisconsin? +
The average last spring frost date for Eagle River, Wisconsin (ZIP 54521) is around Tuesday, May 5, 2026. This is based on NOAA climate normals for USDA Zone 4b.
How long does Lupine take to grow? +
Lupine typically matures in about 365 days from direct sowing. In Eagle River, that means you can expect harvest around Tuesday, April 7, 2026 plus 365 days.
Should I start Lupine indoors or direct sow in Wisconsin? +
Lupine does best when direct sown outdoors. In Eagle River, sow directly around Tuesday, April 7, 2026.
Other Plants for Eagle River
Growing Lupine in Zone 4b
Lupine (Lupinus polyphyllus) is a popular garden vegetable. In Eagle River, Wisconsin, which is in USDA Hardiness Zone 4b, you should direct sow seeds around Tuesday, April 7, 2026.
Your average last frost date is Tuesday, May 5, 2026. Lupine grows well when direct sown, as it doesn't transplant well or germinates quickly outdoors.