Species

Lupinus polyphyllusBigleaf Lupine

25 other cultivars

perennialN. America Native

My Castle lupine

Lupinus polyphyllus 'My Castle'

The Story

Plant Bio

Lupinus 'My Castle' is a clump-forming perennial with palmate, mid-green leaves and tall, dense spires of pea-like, brick-red flowers in late spring and early summer.

This cultivar features especially robust foliage and denser flower spikes compared to other Lupinus polyphyllus cultivars.

Uses & Benefits:

Lupinus polyphyllus 'My Castle' adds vibrant blue color to gardens, attracting pollinators and creating a stunning visual impact.

Provides nitrogen fixation, enriching soil health naturally.

Supports bees, butterflies, and hummingbirds, promoting biodiversity.

SpeciesLupinus polyphyllusBigleaf Lupine

Essentials

At a Glance

Plant Type

Perennial

Height

36 inches

Width

15 inches

Light

Full Sun, Partial Sun

Zones

4, 5, 6, 7, 8

Water

Moderate

Humidity

Average

Lifespan

Short-lived Perennial

Native To

North America

Toxicity

Toxic to humans and pets if ingested

Bloom period

Late spring – Early summer

In flower about 2 months of the year

Planting

How to Grow

Tuck seeds into well-draining soil in early spring.
Mist cuttings lightly to maintain moisture during root development.
Transplant seedlings when they are 4 inches tall and roots are established.
Space plants 12–18 inches apart for optimal growth.
Mulch around plants to retain moisture and suppress weeds.
Fertilize with a balanced, low-nitrogen fertilizer in spring.

Pro Tip

Soak seeds in warm water for 24 hours before sowing to improve germination.

Keep It Thriving

Care Guide

Do

Water regularly, especially during dry spells 💧
Prune dead or damaged stems to encourage healthy growth ✂️
Apply a balanced fertilizer in early spring
Mulch around base to conserve moisture
Monitor for pests and treat promptly

Don't

Avoid overwatering to prevent root rot ❌
Do not fertilize with high nitrogen fertilizers which can promote excessive foliage
Never disturb roots during flowering

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Deadhead
Pest Check
Stake

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Colorful perennial borderWildflower meadow accentPollinator-friendly garden

Companion Plants

Echinacea Rudbeckia Salvia Coreopsis Gaillardia

Multiply

Propagation Methods

Good to Know

Common Questions

My Castle lupine questions

What zones can My Castle lupine grow in?

My Castle lupine is hardy in USDA Zones 4–8. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

Is My Castle lupine deer resistant?

Yes — My Castle lupine is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.

When does My Castle lupine bloom?

My Castle lupine typically blooms in late spring through early summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does My Castle lupine need full sun?

My Castle lupine does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.