Ash thrives best in fertile, deep and well-drained soil in cool atmospheres. It is native to Europe, Asia Minor and Africa and is also found from the Arctic Circle to Turkey. It is the third most common tree in Britain. It is often found as a pioneer species and colonises urban areas readily. The immature seed can be pickled by steeping in salt and vinegar, and then used as a condiment for other foods or added to cheeses, coleslaws, pickles, kimchi or similar. Ash trees are in the olive family (Oleaceae) and produce an edible oil from the seed that is chemically similar to olive oil.