Biodynamic gardening and agriculture was developed in the early 20th century in response to the detrimental effects of the increased use of chemical fertilizers. According to The National Sustainable Agriculture Information Service, "Biodynamic agriculture is an advanced organic farming system that is gaining increased attention for its emphasis on food quality and soil health." Biodynamic theory covers all aspects of farming.
Biodynamic systems view the farm or garden as a self-contained organism with its own individuality. Emphasis is put on the integration of crops and livestock, nutrient recycling, soil health and holistic management practices. Planting is done according to astrological rhythms. Each part of the farm ecosystem is understood in relationship to the effect it has on all parts. Biodynamic agricultural schools were the first to establish an organic labeling system for their foods.
Soil health is important to biodynamic agriculture systems. Its founder, Rudolf Steiner, identified plant extracts and preparations that enhance soil quality and stimulate plant life. Yarrow, stinging nettle stalks, flowers and leaves, chamomile, oak bark, dandelion and valerian flowers are used in homeopathic amounts to stimulate growth. They are made into spray or tea.
Garlic oil, crushed garlic and garlic extract as pest sprays are not permitted in biodynamic disease and insect control systems. Biodynamics is an organic gardening system but does not use many of the well-known organic methods for pest control. Companion planting with garlic is permitted. Garlic is known to be an effective natural deterrent to aphids, apple scab, borers, Japanese beetles, peach leaf curl disease and spider mites.
There are many methods of organic gardening that use and recommend garlic spray as one component of an integrated pest management system. Garlic spray is effective on roses as a deterrent to aphids and mites. Garlic spray can be made by putting a garlic bulb into a blender with two cups of water, letting it sit for a day and using it in a hand or hose sprayer.
Foliar sprays used in biodynamic gardening are fermented plant extracts similar to compost tea. Biodynamic gardeners use them as a source of soluble nutrients, to stimulate plant growth, to suppress disease and as carriers of cosmic and earthly force. The biodynamic system includes planetary and astrological influences. Foliar sprays are also referred to as immune-building plant extracts, plant tonics, biotic substances and biostimulants.