Making horn manure 500: the complete guide from cowpat to preparation

Horn manure, preparation 500, is the soil preparation of biodynamics. It is used to stimulate soil life and humus formation and to lead the roots down into the depth. Demeter farms apply it at least once a year on all their land.

It is made from two things a farm with cows has anyway: fresh cow manure and cow horns. Around Michaelmas, at the end of September, the manure goes into the horns and the horns go into the ground. Around Easter they are dug up again. The horn then holds a dark, crumbly mass that smells of woodland soil.

This guide takes you through every step: which horns are suitable, which manure, how to lay out the pit, how to recognise good horn manure and how to store it. It draws on the workbooks by Christian von Wistinghausen, the handbook by Walter Stappung, Pierre Masson and the introduction to the preparations by Demeter Switzerland.

At a glance

The horn manure year

Horn manure needs half a year in the ground and a few weeks of preparation. If you want to start in autumn, get the horns in late summer and change the cows' feeding.

• August to September: get the horns, remove the bone cores, clean the horns. Choose the site for the pit. The cows get hay in addition so that the manure becomes firmer.
• Around Michaelmas: collect the manure, fill the horns, bury them the same day.
• October to March: the horns lie in the ground. Frost and snow are part of it.
• Around Easter: dig a test hole, then lift the horns as soon as the soil has dried off.
• April to summer: store the horn manure and check it often in the first months. It takes three to six months until it has fully settled.
• Spring and autumn: stir it and spray it onto the soil.

What you need

For the horn manure itself:

• cow horns, four per hectare and spraying
• fresh cow manure, one litre for five horns
• a site with deep, humus-rich soil

Tools and equipment:

• a bucket with a lid and a bricklayer's trowel or dustpan for collecting
• a spoon, a spatula or narrow wooden slats for pressing the manure in, a hardwood board for tapping
• for larger quantities, a sausage filler
• a spade, a shovel and a large spoon for the fine work when lifting
• a wire loop or bent wire for emptying the horn tips
• a bottle brush and water for the empty horns
• a container of stoneware, clay, wood or glass, and peat or coir for storage
• a notebook for the sketch of the pit and the dates

How much you need

Wistinghausen gives a simple calculation for this:

hectares × sprayings × 4 = number of horns horns ÷ 5 = litres of fresh manure

A farm of 20 hectares with two sprayings a year therefore needs 160 horns and about 30 litres of manure. Demeter Switzerland reckons with one to four horn contents per hectare. Farms in conversion, small farms and those with scattered fields use two to four; large Demeter farms that have been biodynamic for a long time also use less than one. One horn's content of horn manure can be roughly enclosed in one hand.

In garden, vegetable and fruit growing, Wistinghausen reckons with double to four times the amount of preparations. For a home garden the content of a few horns is enough. Even so, it pays not to fill too few: Alan Johnstone buries at least eight horns together.

A horn can be used three to five times. Once you have bought a set, in the following years you only need replacements for horns that flake or crack.

Step 1: Getting and preparing the horns

How to recognise a cow horn

In the Agriculture Course Rudolf Steiner expressly asked for cow horns. In his words, horns from oxen would most probably not work, and bull horns relatively weakly: "That is why I always say cow horns; cows are as a rule female!"

You recognise a cow horn by its calving rings. With each birth and the start of lactation the horn grows less in thickness for a while, and a constriction forms at its base. A cow horn is heavy, thick-walled, slender and more or less spirally twisted up to its full tip. Bull horns are thick and short, ox horns thick and long. Both are thinner-walled and sound hollow when you knock on them.

Steiner drew the size on the blackboard: about 30 to 40 centimetres, the horns of Allgäu cattle. In the local breeds a horn holds 100 to 250 millilitres. Very large horns, such as those of Longhorns or zebus, are too large for Central Europe. Masson has seen the manure stay green in them.

Ideally the horns come from middle-aged cows. Helga Wagner takes horns with three to eight calving rings. Wistinghausen recommends native animals, and as a stopgap cows from your own continent. Steiner spoke of the relationship between the horns and the region: a cow that has grazed on one soil for three to four years belongs to that soil.

Where the horns come from

The horns of your own cows suit the farm best. Most farms, however, need more than they produce, and many have no horned cows. Since disbudding became widespread, cow horns have been scarce. Sources are collection points of the biodynamic associations and working groups, abattoirs, and farms that pass on prepared horns.

Horns straight from the abattoir have often been boiled and dried at high heat. They become brittle, splinter and last fewer years. According to Wistinghausen, boiled, deformed or damaged horns are unsuitable.

Removing the bone core

If the horns still have the bone core, put them in a plastic sack in the sun, cover them lightly with straw or bury them in the compost. After five to fourteen days the horn can be pulled off the core or knocked out. It is important that the horns stay moist during this. If the skin between horn and core dries out, the core stays stuck.

Stappung strikes the horns hard with their inner curve over a hard edge, an old railway rail or a thick hardwood board, until the core flies out. A clear space is advisable; the core flies fast. Most avoid boiling. A short scalding at 60 to 80 degrees, for no more than 20 minutes, also loosens the connection and does not make the horn brittle.

Preparing the horns

Horns that have already held horn silica are not used for horn manure. Wistinghausen uses silica horns only once. Before filling, rinse the horns with clean water. Slightly moist inside, the manure slides in more easily.

Step 2: Getting the right manure

The quality of the preparation depends on the manure, and the manure depends on the cows and their feed. Stappung calls cow manure a mirror of how the farm is run.

The cows and their feed

Wistinghausen takes fresh, straw-free, firm and well-formed manure from pregnant cows. The best manure comes from grazing or from grass-clover with added hay or straw. Silage and beet leaves in the feed make the manure unsuitable for horn manure. Ehrenfried Pfeiffer excluded manure from sick animals and from intensive concentrate feeding.

If you adjust the feeding specifically for the preparations, there are a few proven tricks:

• Offer hay. Stappung starts feeding hay ad lib a month before collecting and changes slowly from grass to hay. This gives the manure structure.
• Take away the salt. Uli Hack removes the salt lick five to seven days before collecting; Masson also feeds no salt then. Without salt the cows drink less and the manure gets thicker.
• Treat the feed with horn silica. Masson sprays horn silica on the regrowing grass at the end of August or early September. Especially after a damp summer with little sun, manure from untreated feed otherwise easily stays green.
• Bring single cows indoors. If you do not want to change the whole herd, bring two or three dry cows indoors for a few days and feed them hay. Christoph Willer in Brodowin needed two to three days until the cowpats were firm enough.

The test is simple. Stappung fills a horn and turns it upside down. If the manure slides out at the slightest movement, it is too wet.

Collecting

In Central Europe collecting takes place around Michaelmas, at the end of September, fresh on the pasture or in the barn before bedding is put down. On the pasture you slide the trowel under the cowpat, lift it and lay it upside down in the bucket. That way you can pick off stalks, grass and clods of soil before the next pat goes on top. In the barn cows like to dung in the morning when they get up. If you come early, you catch the pats with the shovel.

Pure manure without soil, grass and bedding is best. Ideally it is filled the same day. Peter Blaser observes that manure filled while still warm from the cow transforms best. According to Wistinghausen it stays in the bucket no longer than two days, and never in frost.

Step 3: Filling the horns

The manure is pressed into the opening by hand, with a spoon or with a wooden spatula. Then tap the horn a few times on its tip on a hardwood board so that the manure settles right into the tip. Stone is too hard for the horn. It goes more easily if you first put in a little manure, tap, and then fill further. The horn should be completely full, without air pockets. There is no need to hammer too hard.

If the manure is very soft, first push a drinking straw right into the tip. While filling, the air escapes through the straw; afterwards you pull it out.

After filling, wipe the outside of the horn clean. Peter Proctor cleans off clinging manure because it attracts worms. The horn needs no seal of clay, bladder or pitch. Stappung considers it unnecessary; with pig bladders the manure transformed less well for him.

With a sausage filler

For larger quantities, according to Wistinghausen, a hand-operated sausage filler has proved its worth. Stappung works with the widest nozzle; for native horns a length of twelve centimetres is enough. He pushes the horn as far as possible over the nozzle and holds it only lightly, with two fingers. When he feels resistance, the tip is full, and he pulls the horn back slowly, with a spiral movement for wide horns. When changing horns he turns the crank back a little so that nothing runs on.

Fill the cylinder without trapping air. If the manure jams in the nozzle, pull the piston back at once and clear the blockage. Pure, pulpy manure does not block; straw and dried crusts do. Two people are quickest: one turns the crank, one holds the horns. Wistinghausen also describes a barrel funnel with a matching tamper.

Step 4: Laying out the pit

The right site

Steiner asked for a soil that is "not too clayey and not too sandy", and when asked, "the deepest cultivated layer". Below the cultivated layer, said Steiner, no useful effect is achieved. Wistinghausen digs into deep, humus-rich arable or meadow soil. To be avoided:

• waterlogging
• the crown and root zone of trees and shrubs
• the vicinity of walls, roads and ditches
• electric fences and other electrical installations
• soil that has been treated with synthetic chemicals

Masson first cultivates a new preparation site for two years and treats it with the preparations before burying there. Where the soil is naturally good and has been farmed organically for years, according to Stappung it can be done sooner.

A pit in a corner of a field, its centre ten metres from the field edges, has proved itself. Others place it close to the house, where they can keep an eye on it and step in during great drought or wet. Mark the spot and record it in the farm notebook with a sketch and measurements from the field edge. Wistinghausen keeps a distance of 50 metres from the pits of the other preparations where possible.

Dimensions and layout

The horns go 30 to 50 centimetres into the ground, so that 30 to 40 centimetres of soil lie above them. If the soil is shallow, dig the pit 50 to 60 centimetres deep and put in ten centimetres of humus-rich topsoil.

The horns are laid close together, the opening slightly lower than the tip. That way no seepage water collects in them. Fill the gaps with crumbly soil, crumbled between your hands if necessary. Each horn should be completely surrounded by soil. If hollows remain, fungi grow there. Two to three layers on top of each other are possible, with soil again between the layers.

A long, narrow pit has proved itself. You fill it from one short end, layer by layer, and cover each section straight away with the soil dug from the next. In spring you empty it the same way. Finally all the excavated soil goes back, preferably mixed with good soil. Sow something on top, such as mustard or legumes, so that the spot is green.

Difficult soils

• Clay, waterlogging, a lot of rain: drain the pit or keep it shallower and heap the soil over the horns as a mound. The garden at the Goetheanum does it this way too. Hilde Pfeiffer "mounded" on shallow soils and covered the mound with the cut-out turf.
• Sand: mix mature compost and a little clay into the pit. Burying somewhat deeper helps against drying out.
• Shallow or rocky: Peter Proctor mixes humus-rich soil or mature compost one to one into the pit.
• Calcareous and very active: lift early, before earthworms and soil life consume the preparation.

In the home garden

In the garden the pit is easiest to lay out on a cleared bed that stays empty over winter. There is enough loose soil there for a small mound. The spot is close to the house, and you are sure to find it again in spring.

Step 5: Over the winter

Steiner describes winter as the time when the Earth is most inwardly alive:

"And the manure content of the cow horn, with these forces, which now draw in everything from the surrounding earth that is enlivening and astral, the whole content of the cow horn is inwardly enlivened throughout the whole winter, when the earth is thus most alive."

Rudolf Steiner, Agriculture Course, lecture 4 (GA 327)

Frost is part of it. Asked whether it harms the preparations, Steiner replied that it is precisely in frost that the Earth is most exposed to cosmic influences. So the pit needs no protection from frost. Masson covers it with corrugated iron when a lot of snow is forecast, because snow soaks the soil too much, and he also puts the sheet on a month before lifting so that the soil dries off.

For a long time the manure shows no change. According to Stappung, horn manure only becomes darker in the last two weeks before lifting.

Step 6: Lifting

When

The horns stay in the ground over winter until spring cultivation, in Central Europe usually around Easter. Demeter Switzerland gives end of March to end of April; sometimes the horn manure is only ready in early May. Masson lifts in the week after Easter.

Before you open the whole pit, dig a test hole in one place. If the soil is still wet from winter, wait until it has dried off. Do not wait too long: from May, earthworms move into the horns and growing plants push their roots into them.

How

Horn manure horns are robust. Still, lift them out carefully so that the content does not fall out too early. Clean the soil off the outside with a spoon, a brush or the back of a knife, right after lifting. The soil holds moisture and wears the horn.

Then it is best to let the horns dry off for a few days under cover, spread out or in stacked crates. Once dried off, the content slides out more easily. To empty them, knock two horns against each other, openings down, over a container. A wire loop fetches the rest from the tip. For large quantities compressed air through a long nozzle helps.

How to recognise good horn manure

Good horn manure is dark brown through and through, moist, soft and mouldable, and smells of humus-rich soil, not of manure. It can be kneaded and balled but does not stick to the fingers. Masson compares the consistency with fresh earthworm casts. Franz Dreidax described the smell while stirring as woodland soil, humus and violets. White fungal threads on the surface are a good sign according to Peter Proctor.

Not every horn succeeds. The table helps with judging:

Small red compost worms in mature horn manure, on the other hand, are welcome. Masson values them as part of soil life.

Maturing and storing

Fresh from the horn, horn manure has not yet fully settled. According to Stappung it takes three to six months until the individual plugs have become an even, crumbly mass. It then sinks together a little.

It is stored dark, cool and frost-free in a casing of peat. Wistinghausen stores it either in the horn, wrapped in dry peat, or knocked out in a container of wood, clay or stoneware, surrounded all round by at least five centimetres of peat. Demeter Switzerland gives six centimetres of peat or ten centimetres of half peat, half coir. The lid only rests on top; the preparation must breathe.

Balls have proved themselves. Knead the content of about four horns into a ball of eight centimetres and let it dry off for a few days in airy shade, just enough that no worms or seeds develop in it any more. That way the horn manure keeps into the next year.

In the first two to three months, check it often. If it is too wet, spread it out for a few hours in the shade on a wooden rack or a cotton cloth. If it is too dry, add a few drops of rainwater. If there are too many worms, pick them out and put them on the compost.

Wistinghausen makes horn manure anew every year. A small remainder from the previous year is mixed with the fresh and used up. The whole matter of storage, from the preparation box to the right place in the house, is described in the lexicon entry Storing the preparations.

Caring for the empty horns

Wash the horns straight after emptying, before manure dries on in them. Soaked, manure and soil come off more easily; inside, a bottle brush and a strong jet of water help. Then let them dry in the sun or with the opening facing down. Completely dry and free of manure, they decompose more slowly.

Steiner suggested keeping the horns in the cowshed, and many still keep them there today, airy in a sack. Some mark each horn with a notch for every year. If the shiny inner layer flakes off or the horn cracks, it is replaced. Spent horns go into the planting hole of trees and shrubs, where they feed the soil life for a long time.

How much work it is

Demeter Switzerland has recorded the time needed for a farm of 30 hectares with two horn manure sprayings a year:

The making itself is done in a few days; winter does the rest. Demeter Switzerland calls making your own preparations healing work for your own farm or garden.

Making it together

Horn manure is often made in a group. One person collects, two fill, one digs. Stappung makes his preparations with a whole group and buries them all on the same day, close together, within calling and sight distance. Many farms invite people to a preparation day, and many regions have preparation circles that make and share the preparations together. Anyone without cows of their own finds manure and horns there and learns the work alongside people who have done it for years.

From the horn to the field

Before application, horn manure is stirred for an hour in hand-warm rainwater: form a deep vortex, change direction, form the next vortex. The whole technique is in the article Stirring the preparations.

It is sprayed in the late afternoon or evening, in large drops onto the soil, in spring and autumn when the soil is warm and moist. If you work with the calendar, put horn manure in the descending Moon, ideally on root days. Quantities, timings and the rules for each crop are in the article Applying horn manure 500.

Making it yourself or buying it in

For your own horn manure you need access to cows, a handful of good horns with calving rings, a day around Michaelmas and a site with deep soil. Your first own horn manure is ready in spring. For the autumn spraying before that, and for the first years while the preparation site is still developing, many buy it ready-made.

The Präparatekiste sells its own horn manure, packed for garden and farm or loose by the gram, as well as cow horns for making your own and coir for storage.

Frequently asked questions

When is horn manure made?

Filling and burying take place in autumn around Michaelmas, from the end of September to mid-October. Lifting takes place in spring around Easter, from the end of March to early May.

Which manure is suitable for horn manure?

Fresh, firm, straw-free cow manure, ideally from pregnant cows on pasture or fed on grass-clover and hay. No manure from silage, beet-leaf or concentrate feeding and none from sick animals.

Can I also use manure from horses, sheep or goats?

Horn manure is made from cow manure. Steiner called it "undoubtedly" the best material for this work.

Why does it have to be cow horns?

Steiner expressly asked for horns from cows. Ox and bull horns are not used. You recognise cow horns by their calving rings; they are heavier, thicker-walled and more slender.

How many horns do I need?

Four per hectare and spraying. For 20 hectares and two sprayings that is 160 horns. In the garden a few horns are enough. Alan Johnstone buries at least eight together.

How much manure do I need?

One litre of fresh manure for five horns.

How deep are they buried?

30 to 50 centimetres deep, with 30 to 40 centimetres of soil above the horns, in deep, humus-rich soil without waterlogging.

Does the opening face up or down?

The opening lies slightly lower than the tip, so that no seepage water collects in the horn.

Do I have to seal the horns?

No. A seal of clay, bladder or pitch is not needed.

Does frost harm horn manure?

No. Frost is part of the winter in the ground. Only a great deal of snow can soak the soil too much.

How do I recognise good horn manure?

Dark brown, moist, soft and mouldable like fresh earthworm casts, with the smell of humus-rich soil. If it still smells of manure or is green and wet, it stays in the ground a few weeks longer.

Can I leave horn manure in the ground until I need it?

Steiner considered this possible. In practice, worms and roots attack the preparation and the horns in summer. Most people lift around Easter and store the horn manure in peat or coir.

How long does horn manure keep?

Well stored, formed into balls and dried off, into the next year. It is made anew every year.

How often can I use a horn?

Three to five times, as long as it is hardly damaged. If it flakes or cracks, it is replaced.

Can I make horn manure without cows of my own?

Yes, if you can fetch fresh manure from a farm. Many gardeners join a farm's preparation day or a preparation circle.

Sources

• Rudolf Steiner: Spiritual Foundations for the Renewal of Agriculture (Agriculture Course), GA 327, lecture 4 and answers to questions, lecture 5, questions 25 and 26; quoted after Stappung, chapter 3.
• Christian von Wistinghausen, Wolfgang Scheibe, Eckard von Wistinghausen, Uli Johannes König: Anleitung zur Herstellung der biologisch-dynamischen Feldspritz- und Düngerpräparate (Workbook no. 1), Verlag Lebendige Erde, sections on the horn manure preparation (500), preparation and storage, and quantities required.
• Walter Stappung: Die Düngerpräparate Rudolf Steiners. Herstellung und Anwendung, chapter 3 on the cow horn manure preparation and chapter 13 on maturing and storing the preparations; therein Ehrenfried Pfeiffer, Franz Dreidax, Helga Wagner, Uli Hack, Christoph Willer, Peter Blaser, Peter Proctor, Alan Johnstone, Hilde Pfeiffer.
• Pierre and Vincent Masson: Landwirtschaft, Garten- und Weinbau biodynamisch (2015), chapter on horn manure (500 and 500P).
• Verein für biologisch-dynamische Landwirtschaft (Demeter Switzerland): Präparate. Einführung in die biodynamische Präparatearbeit, chapters on the field spray preparations and on time and costs of preparation work.
• Demeter e. V.: Standards for production and processing 2026, chapter II.2.4.
• Wikipedia: Biodynamic agriculture, Rudolf Steiner, Cattle, Disbudding, Eisenia fetida.