There are many onion varieties with very different characteristics. There are four major groups based on skin colour: yellow, brown, red and white. There are three main onion groups based on light exposure demand: short exposure (8-10 hrs/day – early maturation), moderate exposure (10-12 hrs/day – moderate early maturation) and long exposure (13-15 hrs/day – late maturation). This is also the three groups based on maturation period: early, moderate and late. Early maturing varieties are juicy and sweet with fewer protective layers. This variety known as the summer harvest is unsuitable for storage. Moderate early maturing onions can be stored for 3-5 months whereas the late maturing varieties keep well for 7-8 months. The latter are known as winter onions. The flesh is thinner and denser which is covered by several protective layers making it noticeably stronger in taste.

Shallots are grown extensively in France, Canada and the Netherlands. Shallots are in fact a member of the garlic family which gives them a unique aroma. In Turkey, shallots are grown from the bulb instead of the seed. The harvest time of this variety depends on climatic conditions however it is usually in the first week of June. The earliest harvest takes place in the Gaziantep Region however the extreme heat in this geography shortens the storage life of the early harvest down to three months. Three shapes are cultivated in the Gaziantep Region: round, elongated and semi-elongated. The late harvest is cultivated in the Çorum area where only round shallots are grown. The harvest in Çorum is usually in early September, which offers the advantage of longer shelf life.