Biodynamic preparations 500-508 | The nine Biodynamic preparations 500-508 are fundamental to the Biodynamic way of gardening, farming and wine-growing (see Biodynamics). The names of these nine preparations (‘preps’) are Horn manure 500Horn silica 501, Yarrow 502, Chamomile 503, Stinging nettle 504, Oak bark 505, Dandelion 506, Valerian 507, and Equisetum arvense 508 (Common horsetail). Their regular use in compost or as field sprays is a pre-requisite for any vineyard or other agricultural enterprise to be considered Biodynamic by Demeter, the organization which has regulated Biodynamic farming since it was first described in 1924 (see also Biodynamic certification).

The nine ‘preps’ are made from one or seven wild plants, fresh cow manure, and the mineral quartz (silica). The preps help regulate the farm and the crops, be they perennial wine grape vines, annual vegetables, or farm animals. The idea is that all function healthily, and in a way that also allow them to tune in to both the Earth’s seasonal cycles (autumn, winter, spring, summer) and celestial cycles as a whole, so that the formative forces which Biodynamic farmers see as being able to shape matter (vines, shoots, leaves, buds, vine flowers, grapes, pips, tannins) can do so in the best way.

Three Biodynamic field spray preparations 500, 501 & 508 are sprayed directly on the vineyard or farm individually and at different times during the season. They are Horn manure 500, Horn silica 501, and Equisetum arvense 508 (Common horsetail). Each one is used in isolation and first stirred or ‘dynamized‘ in water. This stirring allows the ‘formative forces’ in each preparation to be transferred to the water and then onto the cropland. The use of water also makes practical sense as it would be impossible to spread Horn manure, Horn silica, or Equisetum arvense across large areas of cropland when only handful or so of each prep is required per hectare per treatment. 

Six Biodynamic compost preparations 502-507 are carefully stored before being added to the compost pile. They are Yarrow 502, Chamomile 503, Stinging nettle 504, Oak bark 505, Dandelion 506, and Valerian 507. The Biodynamic idea of composting waste generated by the farm/vineyard and returning it to the land aims to maintain each farm as self-sustaining living organism. The ‘farm organism’ idea later became the origin of the term ‘organics’ which followed on from Biodynamics and dates from the mid-1940s. Vineyards able to create and then maintain their own fertility might justifiably be said to be practising not just terroir-driven but ‘terroir-enhancing’ wine-growing. See Biodynamics, compost and soil microbiology.

Those unable to apply the six Biodynamic compost preparations to the land via composting may instead do so via sprays such as Barrel Compost created by Maria Thun, Cow Pat Pit developed by Peter Proctor, or 500P developed by Alex Podolinsky. In addition, plant-based sprays (decoctions, teas, liquid manures) are also used in Biodynamics (and of course organics) on the ‘use a plant to cure a plant’ principle.

Summary | For a long, healthy life a vine’s requirements are similar to those of a house: deep foundations, a roof that withstands the elements, and strong supporting walls in between. The three biodynamic field sprays – horn manure 500, horn silica 501 and common horsetail 508 – assist in providing those metaphorical needs. The horn manure 500 soil spray allows strong foundations to form via a strong, complex root system. The horn silica 501 atmosphere spray encourages strong and vertically erect fruiting wood. Equisetum arvense 508 (Common horsetail) mediates between the two, being like a damp-proof course when sprayed either around the base of the house (as a liquid manure soil spray) or like an air-brick to keep the paintwork from going mouldy (as a fresh tea sprayed directly on the vines).

Measuring the effects | Diagnostic tools to gauge whether the often fairly left-field (‘unscientific’) practices used in Biodynamics actually work include–most obviously in wine’s case–comparative blind tastings between conventional, organic, and Biodynamic wines. Diagnostic techniques peculiar to Biodynamics include sensitive crystallization and chromatography, neither of which conventional scientists would endorse. 

See | Setting up a comparative trial between Biodynamics and organics, and the work of Claude and Lydia Bourguignon.


Monty Waldin, Biodynamic Gardening (Dorling Kindersley, 2015).

Monty Waldin, Biodynamic Wine (Infinite Ideas, 2016).