The Walled Kitchen Garden
Fruit and vegetable production
The reason that kitchen gardens existed was to produce fruit and vegetables all year round, and in order to achieve this a sophisticated combination of forcing, retarding and storage was employed to extend the growing season.
Forcing, which means encouraging a plant to develop far earlier in the season than it would do normally, was widely practiced. Hot walls were a method of forcing, and the protection of the walls themselves brought fruit trees into production earlier.
Wall fruit trees were draped with a variety of materials to keep off the frost: canvas mats, straw screens or even branches were all used. Sometimes projecting brackets were fixed onto the walls to provide a structure from which to hang curtains of various fabrics that could be drawn across the trees. This method was improved in the late 19th century when removable glass panels were introduced.
Vegetables such as seakale and rhubarb could be forced by the simple practice of placing forcing pots over the plants. This method also had the effect of blanching them, which made them sweeter, and to this end was used on other crops such as chicory and endives. Cloches (translucent covers) of various kinds were also commonly used.
Hot-beds were another method of obtaining early crops, and were first mentioned by Thomas Hill in The Gardener's Labyrinth in 1577 (Campbell, 2005, p.127). A pile of fresh horse manure was formed into a bed about three foot high and four foot wide, and as long as was desired. Once the heap had fermented sufficiently to produce the required heat, cloches or wooden frames with glass lights were placed over it in order to preserve the heat, and soil, to a depth of about six inches, was placed on top.
A range of crops could be sown into this. In the 18th century it was a popular method for growing melons, but almost anything could be grown out of season in this manner: for instance, salad crops, carrots and early cabbages.
By far the greatest amount of forcing was done in the glasshouses and this will be dealt with later.
Retarding or delaying, while not so extensively practiced as forcing, was still a useful method by which to extend the growing season. Fruit such as cherries and plums, grown against a north wall, would ripen later than elsewhere in the garden. This lateness could be further delayed by placing mats over the fruit to keep off the sun. Soft fruit such as gooseberries and redcurrants were also given this treatment.
Storage was another method of keeping fruit and vegetables beyond their normal season. Potatoes and root vegetables could be stored outside in a clamp, which was made by covering a heap of vegetables with straw and finishing it off with a good layer of earth. However most of the larger gardens would have had some kind of root store - a cellar or brick-lined tunnel that was cool, dry and dark. Here root vegetables could be stacked in layers, each layer covered with dry sand.
Most establishments would have a fruit room for keeping their best apples and pears. These rooms varied in size and grandeur, from a lean-to shed to a free-standing custom-built fruit room, sometimes with a thatched roof. The walls were lined with slatted shelves on which the fruits were carefully placed so as not to touch each other. In some cases individual fruits were wrapped in greaseproof paper. Shutters or blinds at the windows kept the room both cool and dark. There are some good examples of fruit rooms at Knowsley Hall, Liverpool and West Dean in Sussex.
Grapes had their own particular method of storage. Bunches of grapes were cut from the vine with a long stem. Each bunch was then put into a narrow-necked bottle (such as a wine bottle) filled with water, which was placed at an angle on a custom-made rack. If kept in a cool, dark room the grapes could be stored in this way for months. Later in the 19th century specially designed ‘grape bottles' were used, with flat sides for easier storage and a hole in the top side for topping up with water.