A knot garden is a garden style that was popularized in 16th century England [1]: 60–61 and is now considered an element of the formal English garden. A knot garden consists of a variety of aromatic and culinary herbs, or low hedges such as box, planted in lines to create an intertwining pattern that is set within a square frame and laid on a level substrate. The spaces between these lines are often filled with stone, gravel, sand or flowering plants. Traditional plants used in knot gardens include germander, marjoram, thyme, southernwood, lemon balm, hyssop, costmary, acanthus, mallow, chamomile, rosemary, calendula, viola and santolina.
Most knot gardens now have edges made from box (Buxus sempervirens), which is easily cut into dense miniature hedges, and stays green during winters when not all of the "filling" plants are visible or attractive. However, the original designs of knot gardens did not use low box hedges until the late 17th century[1]: 60–61
Historically, knot gardens were located close to English manor houses so that the inhabitants and guests would have a bird's eye view of the intricate designs from the upper story windows.[1]: 31 Most gardens were composed of square compartments set within frames. A small garden might consist of one compartment, while large gardens might contain six or eight compartments. The interior knot pattern could be composed of bands of plants in contrasting colours which are hedged to look like they weave over and under each other. In which case, the knot is referred to as "closed". When knots have bands of plants that do not appear to be interlacing, they are referred to as "open".[2]
The term knot garden is closely tied to the term parterre. During the 17th century, these terms were used interchangeably as they often are today.[3][4] A knot garden, however, technically refers to a garden designed with an interweaving pattern whereas "parterre" is a later French term that refers to all formal arrangement of beds.[5]