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Allium cepa · Amaryllidaceae

Onion

✅ Pet-friendlyBiennial, but cultivated annually for bulb harvest.30 to 60 cm
Full sunModerate watering; avoid waterlogging.EasyTolerates temperatures slightly below zero degrees Celsius.

Description & origin

The onion is a biennial herbaceous plant primarily grown for its edible bulbs. It is one of the oldest and most popular plants in global cuisine. In Portugal, it is widely used in soups, stews, and salads.

Size

Can reach up to 60 cm in height.

Foliage

Deciduous foliage that dries after bulb harvest.

Flowering

This species does not produce flowers in domestic cultivation.

Detailed care

Light

Prefers full sun for healthy growth.

Soil

Well-drained soil rich in organic matter.

Watering

Moderate watering, avoiding waterlogging.

Temperature

Grows best in temperate climates.

Fertilising

Fertilize with organic compost before planting.

Repotting

Transplant when seedlings are about 10 cm tall.

Pruning

Does not require pruning.

Propagation

Propagated by seeds or bulb division.

Common problems

Bulb rot

Caused by excess moisture in the soil.

Downy mildew

Fungal disease affecting leaves in humid conditions.

Onion fly

Insect that lays eggs on bulbs, causing damage.

Uses & curiosities

In the garden

  • Home vegetable garden
  • Herb beds
  • Mediterranean gardens

Other uses

Widely used in cooking as a seasoning and main ingredient.

Did you know…

Onions are known to cause tears when cut due to the release of sulfur compounds.