Container Vegetable Gardening
Indoor gardening has become an increasingly popular pastime during recent years, as many people who enjoy plants but have no outdoor garden area have realized the pleasure and simplicity of growing a wide range of ornamental houseplants. Plants producing edible fruits and vegetables have been rather neglected as candidates for container growing indoors, although a number are as attractive as they are useful. Although few outdoor gardeners have not at one time or another considered making over part of the garden to edible crops, it has been widely assumed that indoor conditions will not meet the requirements of most food plants.
This is not so, and from experience I can introduce you to simple cultivation methods for a wide range of vegetables and herbs that you can enjoy freshly harvested without the benefit of any outside growing area. If you have a patio or balcony where these plants can be sited, so much the better; it will save you space indoors. But if you do not have these facilities, it will make no difference to your gardening success.
Where to start
Leaving aside for a moment the question of which vegetables you can or cannot grow in containers indoors, an important aspect of your choice of crops will be the amount of space in your home which you can allow for an indoor kitchen garden. Fortunately, the principle of this type of gardening does not disqualify one-room dwellers any more than the owners of large houses; restrictions on the area for the food crops mean only that you may wish to be more selective about what you grow in order to produce the most generous cropping within the available space. Indoor gardening dispenses with the outdoor gardener’s problems of local climate, changes in the weather, and thetype in a given location. These conditions are within the control of the vegetable grower who works indoors. The single most important element in siting your plants must be to ensure that they obtain enough light not merely to grow but to thrive.
Sunlight is not just good for plants — it is actually life-giving. Plants manufacture their own food supplies by a process called photosynthesis, whereby the chlorophyll, or green colouring matter in the plant body, is converted into starches by the action of sunlight, which causes chemical changes. Many plants can continue to exist in light levels lower than those which they are naturally adapted to and prefer. But they cannot carry out all their functions if deprived of light, and this is especially important in food crops which are required to be productive as compared, say, to foliage houseplants which are expected to look decorative but do no more than that.
It follows, then, that your vegetable plants should be sited at or very close to a window to obtain the maximum amount of daylight. Light levels drop quite dramatically through the room as the distance from the window increases; it is not easy for us to appreciate these changes, as the light levels required for human sight are not comparable to those needed for healthy plant growth.
The ideal position for many of the plants is within a short distance of a window which receives full sun all day. Most will do very well in this situation but fortunately there are some which flourish easily in less direct sunlight. This means that you can make use of windows which receive sun only in the morning or evening, and even those on the side of the house facing away from the sun; simply choose the vegetables which can grow in that situation.
There is, of course, a notable exception to this rule in the case of mushrooms, a crop which obligingly utilizes dark corners in which to grow. Sprouting beans and seeds, a food source of great nutritional value, can also be sited in some convenient shady place. Germinating seeds do not need light, and filled seed trays can be placed out of sight under a bed, on shelves or on top of a high piece of furniture; they are then moved into the light when growth has appeared above the soil surface.
Even if you have only one well-lit windowsill where you can cultivate plants, you can obtain a useful crop of salad plants such asand tomatoes, a wonderful range of herbs or some of the smaller- such as and sweet peppers. Using the process of small succession sowings, you can start seeds in containers placed away from the window while a crop of plants further on in growth occupy the lightest position, eventually replacing the plants which have cropped with the next batch reaching maturity. This enables you to make economical use of space while arranging for a continuous supply of fresh produce.
Growing under artificial light
If you have a very limited space indoors with good enough light to grow food crops, you can give some of your plants a boost by providing an artificial light source. Daylight fluorescent tubes make extremely good growing lights and these can be fitted to shelving to provide a small extra growing area. Forty watt tubes fitted along the underside of a shelf shed a high light level on the shelf below which is beneficial to plant growth. The tubes do not generate as much heat as ordinary light bulbs, but you should make sure they are not immediately within range of the plant growth; a distance of 6in (15cm) or so from the top of the plants is adequate.
Herbs and small tomato plants are among the crops which do well under artificial light. However, to grow food plants permanently in an artificial light source requires an extended ‘day length’ and not all will thrive under such conditions; so fluorescent light is best considered as a useful supplement to sunlight rather than a substitute.