Permapotes
Onions

Yellow onion

Yellow onion: Sowing, planting and harvest calendar

Yellow onion is a bulb vegetable valued for its aroma and versatility in cooking. It belongs to the species Allium cepa and the Amaryllidaceae family, alongside other cultivated onions. Its name comes from its yellow to golden-brown outer skins. The flesh is generally pale even when the skin looks quite dark. It is not a separate species from red or white onion, but a group of forms with a familiar skin colour.

The bulb consists of thickened, overlapping leaf bases around a very short stem at its bottom. The inner layers are fleshy and store reserves for the plant, while the outer skins become dry and protective. Roots grow from the bulb’s base. This structure is different from a swollen root and explains the rings visible when an onion is cut across. The layers are part of the plant’s storage organ.

The foliage consists of long, hollow leaves, upright and sometimes arching, ranging from green to bluish green. They contribute to the reserves stored in the bulb. Onion generally has a biennial life cycle but is grown as an annual vegetable. When it enters reproduction, a flowering stalk develops with a rounded umbel of many small, pale flowers. This is a different stage from the leafy plant used to produce a bulb.

Yellow varieties differ in shape, size, earliness and keeping quality. Bulbs may be round, flattened or elongated. Bulb formation depends partly on day length, with different responses between varieties. Types intended for different regions or seasons are therefore not interchangeable. Yellow skin alone does not indicate their suitability or how long their bulbs can keep.

Flavour varies too: some onions are more pungent, while others are milder. Raw onion provides a pronounced aroma and a firm texture. Cooking softens it and can bring out a sweeter flavour, particularly in slowly cooked or browned preparations. This change explains its role both as a seasoning and as a main ingredient. A large bulb is not automatically milder than a small one.

In the kitchen, yellow onion accompanies soups, sauces, gratins, savoury tarts and flammekueche. It also flavours vegetable dishes and preparations based on grains or legumes. In a garden, it has slender foliage above the soil and a distinct storage organ. Seeds, young plants and sets are different starting forms of the same crop; sets are small bulbs rather than seeds.

Yellow onion
Yellow onion
Characteristics
  • Lifecycle : Annual
  • Exposure : Full Sun
  • Frost Hardiness : Frost Resistant
  • Cultivation Difficulty : Easy
  • Mature height : 30 cm
Sowing & Planting
  • Greenhouse Growing : Not Required
  • Sowing Depth : 2 cm
  • Plant Spacing : 10 cm
  • Row Spacing : 20 cm
Maintenance
  • Maintenance : Low
  • Water Requirements : Moderate
Other characteristics
  • Soil Type : Humus-rich
  • Soil pH Preference : Neutral
  • Pest Sensitivity : Moderate
  • Disease Sensitivity : Moderate
  • Weed Sensitivity : Moderate
  • Pollination : Insect-pollinated
  • Propagation : Sowing