A parterre garden is a formal garden constructed on a level surface in a symmetrical pattern. Generally, they consist of planting beds edged with low uniform hedging surrounded by gravel paths arranged to form an organized and pleasant symmetry. The formal element of a parterre garden often does not contain flowers, and, when the garden was planted during the restoration, herbs were used as a reflection of a traditional parterre. The castle parterre garden is a simple symmetrical design created with box hedge (four squares, divided into four triangular beds, each of which contains a bay tree and various herbs). In medieval times a garden was not just for ornament, it also provided herbs to use in cooking and plants that were used for medicinal purposes. Herbs and plants grown in
manor and castle gardens basically fell into one of three categories: culinary, medicinal, or household use. Many of the plants in the castle garden can fit into one or more of these categories and some have very interesting historical uses. Beautiful blooms can be seem around the walls of the garden in summertime.
The Allee at Drimnagh Castle was created using European Hornbeam - Carpinus betulus. An Allee is a common feature in manor house and castle gardens. They were associated with leisure - a place where women and couples would promenade in the shade. The Allee at the castle is beautiful any time of the years and it changes throughout the seasons from a lush green canopy in summer, to a bright yellow canopy in Autumn and leafless in winter. A favourite to visitors year-round. In the springtime the Allee features a wide variety of spring flowers - tulip, daffodil, wild garlic, crocus, lenten roses, bluebells and snowdrops.