A knot garden is a garden of very formal design in a square frame, consisting of a variety of aromatic plants and culinary herbs. The idea of a knot garden came about in the Tudor reign of England and progressed through the Elizabethan age with knot gardens constructed to copy the beautiful embroidery work associated with the English period. A true knot garden involves a very formal almost symmetrically perfect garden. A true knot garden has its woven effect which is the distinguishable feature of these type of gardens. Many of the knot gardens were constructed totally of herbs. A boxwood border could have been introduced as the border with the herbs weaving there way in a pattern over the boxwood into a woven pattern in the center. The problem with either approach is the time consuming almost daily clipping and trimming of this garden to keep the perfect shape. For this reason alone the knot garden has developed into a less labor intensive design for the modern gardener called parterres.
You can make an evergreen outline of your knot garden using various plants and creating squares, rectangles, or octagons and placing mass plantings of annuals, perennials, herbs and vegetables in the center of your parterre providing a good blend. The knot garden and or parterre in modern times has become almost interchangeable in meaning.