The kitchen garden of Jehay, the current placement of which dates back to the 19th century, has a surface area of one hectare. It was restored during the course of 2011 by Province de Liège.
The arrangement of the crops meets a number of needs: historical, educational, aesthetic and ecological. Saplings and seedlings are supplied by the Provincial Institute of Agronomic Education of La Reid on the basis of these four fundamental requirements.
Two large kitchen-garden squares are subdivided into eighteen plots, each devoted to one type of crop (onions, cabbages, beans etc.).
Thirty-four varieties of palisaded apple trees and pear trees adorn a section of the north and west walls.
The high-stem orchard accommodates an insect hotel in order to aid pollination and encourage pest control.
Several rows of aromatic and condiment plants are scattered across the kitchen garden: mint, rosemary, sage, lavender, thyme and chive, to name the best-known ones, exude a Mediterranean perfume.
The building integrated with the enclosing wall is an orangery that was built in the 19th century. Orangeries were masonry-built spaces designed to protect large heat-loving plants throughout the winter period, essentially citrus fruits, bay trees and pomegranate trees.
Originally, two greenhouses were located either side of the entrance gate. Only one remains, in a highly deteriorated state, and is currently the focus of a restoration project.