Intensive Vegetable Gardening

The purpose of an intensively grown garden is to harvest the most produce possible from a given space. Methods used in intensive gardening include raised beds, wide or multiple rows, vertical trellising, intercropping, and succession cropping. Traditionally gardens consist of long, single rows spaced 3 feet apart. Much of the garden area consists of space between rows. An intensive garden keeps wasted space to a minimum. A good intensive garden requires planning for the best use of time and garden space.

Raised Beds
The idea of single-row planting started with the use of mules to cultivate the garden. Out of habit, many gardeners still use this system. Raised beds, arranged just wide enough to reach across, are ideal for growing vegetables and small fruit. The use of beds allows you to concentrate soil preparation in small areas, resulting in effective use of soil amendments. A higher percentage of the available growing space is used, there is less room for weeds to grow, and water can be used more efficiently. The yield per square foot from raised beds is often twice the yield from conventional single row gardening.

Soil preparation is the key to successful intensive gardening. Providing extra fertilizer and irrigation will help, but there is no substitute for deep, fertile soil high in organic matter. Humus-rich soil holds extra nutrients and moisture.

Raised beds are generally 8 to 12 inches high and as long as desired. The width should be no wider than 3 to 4 feet so you can work the bed without actually stepping in it. To create a raised bed, use topsoil from pathways and add organic matter. The raised bed does not have to be enclosed or framed. No support material is needed for shallow beds, those less than 6 inches tall. To prevent soil erosion, gently slope the sides of the bed.

If garden soil is not deep, double dig the beds. Remove the top 9 to 12 inches of soil from the bed. Insert a spade or spading fork into the next 9 to 12 inches of soil and wiggle the handle back and forth to break up compacted layers. Mix the top soil that was removed with a generous amount of compost or manure and return the mixture to the bed. It should be fluffy and slightly raised. Continue this action every 6 to 8 inches along the bed.

The sides of an enclosed raised bed are often made of treated wood. Green pressure-treated lumber, has been treated with cromated copper arsenate (CCA) or ammoniated cooper arsenate (ACA). These two preservatives are the safest for the garden because of their very low tendency to leach into soil. Research studies have shown that there is very little chance of ingesting arsenic in vegetables near treated lumber. Because of the arsenic in the wood, however, wear rubber gloves and a dust mask when sawing the lumber. Avoid using creosote-treated railroad ties. Freshly treated creosote lumber can leach into the soil for several years and continues to give off vapors over a seven to nine year period.

Vertical Gardening
The use of trellises, nets, strings, cages, or poles to support growing plants constitutes vertical gardening. This technique is especially suited to gardeners with small garden space. Vining and sprawling plants, such as cucumbers, tomatoes, melons, and pole beans are obvious candidates for this type of gardening. Some plants will twine themselves onto the support, whereas others require tying.

Vertical planting casts a shadow, so avoid shading sun-loving crops, or plant shade-tolerant crops near the vertical ones. Plants grown vertically take up much less ground space, and though the yield per plant may be less, the yield per square foot is much greater. Because vertically growing plants are more exposed, they dry out faster and require more water than if they were spread over the ground. This fast drying is advantageous to plants susceptible to fungal diseases. A higher rate of fertilization may be needed, and soil should be deep and well-drained to allow roots to extend vertically rather than compete with shallow-rooted plants. Vertical gardening is often used with raised beds.

Succession Planting
Succession planting makes the most of an intensive garden. To obtain a succession of crops, plant something new in spots vacated by spent plants. Planting a spring, summer, and fall garden is another form of succession planting. Cool-season crops (broccoli, lettuce, peas) are followed by warm-season crops (beans, tomatoes, peppers), and where possible, these may be followed by more cool season plants, or even a fall/winter crop.

Interplanting
Growing two or more types of vegetables in the same place at the same time is known as interplanting. This technique has been practiced for thousands of years, but is just now gaining widespread support in this country. Proper planning is essential to obtain high production and increased quality of the crops planted.

The following factors must be considered for each plant you think about planting: length of growth period and pattern (tall, short, below, or above ground); possible negative effects on other plants, such as, the competition by plant produced toxins (allelopathic chemicals produced by sunflowers and Jerusalem artichokes); preferred season; and light, nutrient, and moisture requirements. Interplanting can be accomplished by alternating rows within a bed (plant a row of peppers next to a row of onions), by mixing plants within a row (leeks and parsley), or by distributing various species throughout the bed. For the beginner, alternating rows may be the easiest to manage at first.

Long-season, slow maturing (like peppers) and short-season quick-maturing (like radishes) plants can be planted beside each other. The radishes are harvested before they begin to be crowded by the peppers. An example of combining growth patterns is planting smaller plants close to larger plants (radishes at the base of broccoli). Shade tolerant species like lettuce, spinach, and celery can be planted in the shadow of taller crops. Interplant heavy feeders, such as cabbage family crops, with less demanding plants.

Interplanting can help keep insect and disease problems under control. Pests are usually fairly crop-specific; they prefer vegetables from one plant family. Mixing plant families breaks up expanses of pest preferred crops and confines early pest damage within a small area, thus allowing the gardener more time to manage the pests. A disadvantage is that it’s hard to ensure that all plants are protected when spraying is necessary. Avoid overcrowding which can lead to the development of plant disease because of decreased air drainage and increased humidity.

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