HO-200
Container and
Raised Bed Gardening
HOME YARD & GARDEN • DEPARTMENT OF HORTICULTURE
PURDUE UNIVERSITY COOPERATIVE EXTENSION SERVICE • WEST LAFAYETTE, IN
B. Rosie Lerner

Gardening in containers or raised beds can be just the answer for would-be gardeners who would love to grow their own vegetables and flowers, but lack the space or physical ability for a traditional garden. Growing plants in containers provides an opportunity to garden on patios, porches, balconies, and even windowsills. Raised beds can be used to overcome poor-soil conditions and bring the garden to a height that is more easily reached. While container gardens can be very productive, they do require some special attention.

Containers
Containers that can be used for gardening are limited only by your imagination. Clay, wood, plastic, cement, and metal are all suitable materials for growing plants. Many items around the house can be modified for use as plant containers such as pots, tubs, crates, buckets, bushel baskets, whiskey barrels, tires, wheel barrows, and hanging baskets. Whatever the material, a container must provide drainage of excess water and sufficient space for roots to grow.
When excess water can not escape the container, soil pores that should hold air will be filled with water and roots will die from lack of oxygen. To provide drainage, three or four small (1/4 inch) holes can be drilled in the bottom of the container. Holes larger than 1/4 inch in diameter will allow too much soil to escape. A layer of gravel or pieces of broken pottery can help stop the flow of soil through larger holes.
Wooden containers should be made of a naturally water resistant wood such as redwood or cedar. If chemically preserved wood must be used, choose wood which has been pressure-treated with copper such as chromated copper arsenate (CCA) salts (often sold as Wolmanized lumber). Copper and zinc preservatives which are painted onto the wood are less effective in preventing decay. Do not treat wood with creosote or pentachlorophenol (Penta) because of potential toxicity to plants, particularly when grown in a small, enclosed area.
Most vegetables and flowers have a rooting depth of 2 to 3 feet in good quality soil, but can be grown in shallower soils. Plants whose roots are restricted will be smaller, less productive and may produce smaller-sized fruits. Small containers dry out more quickly, requiring frequent watering. A minimum
depth of 10 to 12 inches is recommended for most plants exposed to drying wind and sun.

Growing Media
A lightweight, well-drained and well-aerated media is best for growing plants in containers. Garden soil alone will soon become compacted in a container garden, leading to poor aeration and water drainage. Premixed potting soil or soilless mixes are offered by many garden supply stores and are ideal for small containers. For larger scale container gardening, mixing your own media may be more economical (see Figure 1 below).

■To make 1 bushel of soil mix:
1/3 bushel soil
1/3 bushel organic matter (compost, peat moss, well-rotted manure)
1/3 bushel vermiculite or perlite
1/2 cup 5-10-5, 6-10-4, or similar fertilizer

■ Or, to make 1 bushel of soilless mix:
1/2 bushel peat moss
1/2 bushel vermiculite
1/2 cup ground limestone
1/2 cup superphosphate
1 cup 5-10-5, 6-10-4, or similar fertilizer

Figure 1. Recipes for Growing Media

Planting
Planting your container garden is much like planting a traditional garden bed. Seeds can be planted in rows or in clusters, depending on the size and shape of the container. By planting transplants rather than seeds, plants will have a head start on the growing season.
Plants that are naturally smaller in size are better adapted to the confines of a container garden. But even large plants such as tomatoes, melons, and squash can be productive if given a large enough container. Many garden catalogs now feature compact cultivars of flowers and vegetables which are more suitable for growing in containers or other