The traditional kitchen garden, vegetable garden, also known as a potager (from the French jardin potager) or in Scotland a kailyaird, is a space separate from the rest of the residential garden – the ornamental plants and lawn areas. It is used for growing edible plants and often some medicinal plants, especially historically. The plants are grown for domestic use; though some seasonal surpluses are given away or sold, a commercial operation growing a variety of vegetables is more commonly termed a market garden (or a farm). The kitchen garden is different not only in its history, but also its functional design. It differs from an allotment in that a kitchen garden is on private land attached or very close to the dwelling. It is regarded as essential that the kitchen garden could be quickly accessed by the cook.

Historically, most small country gardens were probably mainly or entirely used as kitchen gardens, but in large country houses the kitchen garden was a segregated area, normally rectangular and enclosed by a wall or hedge, walls being useful for training fruit trees as well as offering shelter from wind. Such large examples very often included greenhouses and furnace-heated hothouses for more tender delicacies, and also flowers for display in the house; an orangery was the ultimate type. In large houses, the kitchen garden was typically placed diagonally to the rear and side of the house, not impeding the views from the front and rear facades, but still quick to access. In some cases, hardy flowers for cutting were grown outside there, rather than in the flower garden. A large country house hardly expected to buy any vegetables, herbs or fruit, and the surplus was often distributed as presents; the walled example at Croome Court in England covers seven acres, and the gardens have a large "Temple Greenhouse", an orangery in the form of a Roman Temple.

A symbol of American self-sufficiency and the colonial homestead, practical kitchen gardens were the center of home life in early America. In Europe, especially Britain, the difficulties in food supply during World War II resulted in a huge, if temporary, upsurge in growing vegetables in small gardens, with much encouragement from the government Ministry of Food. In modern gardening, there has been interest in integrating the growing of food plants within a mainly ornamental garden; fruit trees and cooking herbs are the simplest and most popular expression of this.

In large country house gardens, the walls also served to hide the kitchen garden, as "a place of base labour ... from the more polite areas", which included the often very extensive fruit gardens and orchards. The gardeners were often, depending on the season, the number of guests, and the whim of the owner, expected to keep out of the main "best garden" during the fairly predictable parts of the day when the family and guests were likely to be walking in the garden, and the kitchen garden provided somewhere for them to occupy themselves at these times. Mostly, visitors were probably not expected to venture inside without leave. But some owners, from Louis XIV downwards, liked to show guests the kitchen garden, especially if they knew they had an interest. In the gardens of Versailles, the enormous potager area, not contiguous with the main gardens, had a wall that was thick enough for visitors to accompany the king in walking along the top for a better view, as on castle battlements.

The French doctor and printer, Charles Estienne, wrote in detail about the 16th century kitchen garden in Maison Rustique; his book was largely compiled from classical authors. This practical garden was to be separated from the pleasure gardens, enclosed by a thick hedge or wall. Estienne viewed hedges as more resilient, cost effective and were easier to repair and maintain, but at least in later periods, walls seem to have been more usual; some were hot walls, with a central cavity gently heated by furnaces. Certainly walls leave more traces behind for the garden archaeologist. The hedge, Estienne says, can be planted with red and white gooseberry bushes, medlar and olive trees, woodbine, whitethorn, wild apples, brambles, and eglantiness. Lattices were woven from willow branches and every year renewed, unless made with juniper poles that had been reinforced with charred oak.

In the Middle Ages, the kitchen garden was often a separate enclosure some way away from the main house. The Covent Garden area of London got its name as the kitchen garden for Westminster Abbey, though some distance from the abbey itself. In Renaissance times, the kitchen garden was rather close to the house, but by the mid-17th-century many were being moved further away, with a service road leading to the main house. At Versailles a public road needs to be crossed to reach it.

In the UK, by the 19th century, as the breeding of vegetable cultivars greatly increased, a plethora of magazines, societies and competitions in local or county fairs, supported what had become (and remains) a popular form of specialist gardening. Some gardeners concentrated on mere size, leading to monstrous (and largely tasteless) strains of vegetables such as leeks. The new allotments, small pieces of a plot of land made available by local councils or charities, often specified that only edible plants were to be grown.

In the early 20th century, the city government of Poznań purchased several small plots of land that it then distributed to families with children. The families cultivated the land with seeds and fertilizer. Crops included carrots, spinach, and beans. The city government found that the plots complemented the diets of the families and looked to expand the program. Some families also grew enough to sell.