Whether your garden beds are for herbs, salads, vegetables or ornamentals, they should have periodic additions of mulch, worm casts, animal manure, compost and other organic materials to maintain soil fertility. A mature system aims for beds with well drained, thick layers of soil, rich in organic matter.
To create a garden bed, work composted manure and trace elements into soil. Gypsum can improve the structure of clay soils and the water holding capacity of sandy soils will be enhanced with the addition of clay.
Use newspaper, cardboard or old (non-synthetic) carpet to sheet-mulch the area. This will suppress weeds and save digging.
On top of the sheet-mulched area apply composted manure, straw, seaweed and a cosmetic layer of mulch like woodchips, bark or sawdust. Water this patch well to break the layers down.
When planting into the beds, punch or slit a small hole into the sheet mulch and fill with fertile soil if needed.
After the first season the soil will contain worms, soil bacteria and fungi. Organic matter is periodically added in the form of composted manure and mulch.
The diversity of plants in the garden beds act as host for a range of beneficial organisms (insects, frogs and birds), which is a major factor in natural pest control.
Garden beds can be built in a number of different shapes and functions as suggested in permaculture publications.
Herb spirals, narrow beds, broad beds, salad clipping beds and keyhole raised beds cater for low growing vegetables. Trellised beds in various shapes are for climbing or staked vegetables such as beans, hops and tomatoes.
In windy conditions, use buildings or hardy plants to create a sheltered area. Lower growing vegetables can be sheltered with trellised climbers.
Part of the fun of permaculture gardening is to experiment and work out the right combination of plants for your situation and climate.