Species

Allium cepaOnion

5 other cultivars

bulb corm tuber

Ornamental Onion 'Mont Blanc'

Allium cepa 'Mont Blanc'

The Story

Plant Bio

Allium 'Mont Blanc' is a bulbous perennial prized for its large, spherical flower heads packed with star-shaped, pure white florets. These impressive blooms are held aloft on tall, sturdy, leafless stems in early summer.

This cultivar is noted for its striking, long-lasting flower heads that resemble snowballs, making excellent cut flowers, fresh or dried. The foliage dies back before the flowers appear.

Uses & Benefits:

Elegant white flowers add a sophisticated touch to perennial beds and borders.

Edible bulbs are used in culinary dishes for their mild onion flavor.

Provides nectar for pollinators early in the season.

SpeciesAllium cepaOnion

Essentials

At a Glance

Plant Type

Bulb Corm Tuber

Height

40 inches

Width

12 inches

Light

Full Sun, Partial Sun

Zones

4, 5, 6, 7, 8

Water

Moderate

Humidity

Average

Lifespan

Perennial

Native To

Central Asia

Toxicity

Toxic to dogs and cats

Bloom period

Early summer

In flower about 1 month of the year

Planting

How to Grow

Tuck bulbs 2-3 inches deep in well-drained soil in fall.
Water thoroughly after planting to settle soil around bulbs.
Mist foliage during dry spells in spring for healthy growth.
Thin out overcrowded plants to improve air circulation in early summer.
Apply a balanced fertilizer in early spring for robust flowering.
Mulch around plants to retain moisture and suppress weeds.

Pro Tip

Plant in full sun with rich, well-drained soil for best blooms.

Keep It Thriving

Care Guide

Do

Water regularly during active growth 🌱
Apply fertilizer in early spring
Ensure good drainage to prevent bulb rot

Don't

Avoid overwatering in winter ❌
Don’t plant too shallow or too deep
Refrain from disturbing bulbs during flowering

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Fertilize
Harvest
Plant
Stake

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Fragrant border with vertical interestScented flower bed accentWildflower meadow element

Companion Plants

Carrots Lettuce Geraniums Rosemary Tulips

Multiply

Propagation Methods

Good to Know

Common Questions

Ornamental Onion 'Mont Blanc' questions

What zones can Ornamental Onion 'Mont Blanc' grow in?

Ornamental Onion 'Mont Blanc' 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 Ornamental Onion 'Mont Blanc' deer resistant?

Yes — Ornamental Onion 'Mont Blanc' is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.

When does Ornamental Onion 'Mont Blanc' bloom?

Ornamental Onion 'Mont Blanc' typically blooms in early summer through early summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Ornamental Onion 'Mont Blanc' need full sun?

Ornamental Onion 'Mont Blanc' does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.

Is Ornamental Onion 'Mont Blanc' drought tolerant?

Yes — once established (usually after the first full season), Ornamental Onion 'Mont Blanc' handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.