Pearl onion

Pearl onions and peas topping a crockpot dish

The "true" pearl onion (A. ampeloprasum var. sectivum or A. ampeloprasum 'Pearl-Onion Group') is a close relative of leek (A. ampeloprasum var. porrum), and may be distinguished from bulb onions by having only a single storage leaf, similar to cloves of garlic. They are cultivated mostly in Germany, the Netherlands, and Italy; usually in home gardens, although formerly on a commercial scale. They are mostly used for pickling.

However, the majority of onions grown for pickling are common onions (A. cepa). They are grown to a small size suitable for pickling by planting at a high density.

Because of its uniquely diminutive appearance and a taste sweeter than that of a bulb onion, it has also been used in dishes ranging from middle 20th century American casserole dishes such as succotash to sweetly-flavored onion relishes in Indian cuisine. A pearl onion will take up to two years to make onions sufficiently sweet for sale (such is the main reason it is less popular in America than other onions).^{[citation needed]} Pearl onions are, however, a staple to the cuisine of Northern Europe, especially Sweden.^{[citation needed]}