Species

Allium cepaOnion

5 other cultivars

bulb corm tuber

Tropea Long Onion

Allium cepa 'Tropeana Lunga'

The Story

Plant Bio

Allium cepa, the common onion, is a biennial plant grown for its edible bulb. It produces hollow, bluish-green leaves and, if left to flower in its second year, a globe-shaped umbel of small, whitish flowers on a tall scape.

This cultivar produces long, cylindrical bulbs that are prized for both cooking and raw use.

Uses & Benefits:

Tall, elegant flower stalks add vertical interest and fragrance to gardens.

Edible bulbs with mild onion flavor enhance culinary dishes.

Provides nectar for pollinators like bees and butterflies.

SpeciesAllium cepaOnion

Essentials

At a Glance

Plant Type

Bulb Corm Tuber

Height

24 inches

Width

8 inches

Light

Full Sun

Zones

4, 5, 6, 7, 8, 9

Water

Moderate

Humidity

Average

Lifespan

Biennial (grown as an annual)

Native To

Central Asia (species); Italy (cultivar)

Toxicity

Toxic to dogs and cats

Bloom period

Early summer

In flower about 1 month of the year

Planting

How to Grow

Tuck bulbs 4-6 inches deep in well-drained soil in fall.
Water thoroughly after planting to settle soil.
Mist bulbs lightly during dormancy in winter if dry conditions occur.
Transplant in early spring if necessary, ensuring proper spacing.
Fertilize with balanced fertilizer in early spring for healthy growth.
Thin out crowded bulbs after foliage dies back.

Pro Tip

Plant in full sun with well-drained soil for best flowering results.

Keep It Thriving

Care Guide

Do

Water during dry spells 🌱
Apply balanced fertilizer in early spring
Mulch to retain moisture and suppress weeds

Don't

Avoid overwatering to prevent bulb rot ❌
Do not plant in poorly drained soil
Refrain from disturbing bulbs during dormancy

Seasonal Care Calendar

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

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Edging with fragrant, purple‑flowered borderScented herb garden with tall, architectural blooms

Companion Plants

Carrots Lettuce Tomatoes Rosemary Chives

Multiply

Propagation Methods

Good to Know

Common Questions

Tropea Long Onion questions

What zones can Tropea Long Onion grow in?

Tropea Long Onion is hardy in USDA Zones 4–9. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

Is Tropea Long Onion deer resistant?

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

When does Tropea Long Onion bloom?

Tropea Long Onion 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 Tropea Long Onion need full sun?

Tropea Long Onion does best in full sun (6+ hours).