Locate next to undesirable blank walls of adjoining land uses. Where possible, it is helpful to have a large, sturdy, continuous, accessible wall to attach the garden.
Ensure that the soil should not just hold water but also have good drainage. Generally a sandy clay loam soil mixed with compost is best for most plants in raised beds. Soil depth in raised beds depends on the plants that will be grown. For shallow rooted plants such as lettuces and herbs, an 8-12-inch depth is considered a minimum. To be able to grow a wider range of crops, soil depth should be between 18 and 24 inches.
Provide an 18-inch minimum space between beds for walkways and maintenance, and a minimum of 36 inches to provide wheelchair accessibility and along major pathways which must be accessible.
Generally, allocate 3 feet by 6 feet as a standard planting bed dimension. This dimension is big enough to support plant growth, but small enough to reach easily from both sides.
Design the sides to be any durable building material with capacity and drainage that is untreated and non-toxic (lumber, layers of rock, cinder blocks, brick, concrete blocks, watering troughs, tubs, etc.).
