Intensive gardening is a centuries-old method designed to maximize yields of vegetables from a garden bed. First practiced by French market gardeners in the 19th century, it is especially beneficial for gardeners with small urban garden plots who wish to grow, rather than purchase, a substantial proportion of their fresh produce.
Construct raised beds for growing vegetables intensively. The soil warms up sooner in spring and the sides define the garden bed while containing the soil. Many gardeners build small beds that can be worked from the edges, without walking on the growing areas. Use 4 by 4 lumber cut to the size of bed you desire. Lay it on the ground, secure the corners with corner brackets and fill in the bed with a mixture of four parts topsoil to one part peat moss and one part compost.
Grow vegetables in wide rows, rather than in traditional rows, with a lot of space between the rows. Traditional garden rows consist of a row one plant wide, with enough space between the rows to cultivate with a rototiller or hoe. Wide rows contain 3 or more "rows" of plants spaced several inches apart within the wide row. Between the wide rows is enough space to cultivate with a rototiller or hoe. Planting this way uses the greatest amount of space within the garden bed, which can be planted directly with crops, rather than used as pathways.
Plant vegetables no farther apart than the minimum spacing recommended on the seed package. This will produce the most vegetables per square foot of growing space. Vegetables planted in this manner grow so closely together that they almost touch, which shades the soil, thus becoming a living mulch. Because the soil is shaded from direct sunlight by the close-together plants, moisture doesn't evaporate as fast, reducing the plants' need for supplemental irrigation. The lack of direct sunlight on the soil also keeps many weed seeds from germinating. Any weeds that do manage to germinate grow thin and spindly.
Practice succession cropping. This method involves planting another crop in the same space where a crop has just been harvested. One example is to plant lettuce or salad greens in early spring. After they are harvested in mid-spring to early summer, immediately plant the space with a hot-weather vegetable, such as green beans. Radishes planted in early spring and harvested a month later can be followed by carrots, peppers or tomatoes.
Apply soil amendments only in the growing beds, not in the pathways. This will concentrate your efforts and improve the soil only where crops actually grow, and will not waste precious compost or peat moss on the pathways where no crops grow.
Grow vining vegetables such as cucumbers, tomatoes, melons and squash vertically. They will take up a fraction of the garden real estate when grown vertically, rather than sprawling on the ground. Construct a trellis using 2-by-2 end poles with nylon or metal garden mesh attached. These crops will grow on the trellis with just a little initial help and encouragement.