Frequently Asked Questions

Q: What is the difference between using the Pfeiffer Compost Starter and the BD Compost Preparations?

A: Dr. Ehrenfried Pfeiffer developed the BD Compost Starter, a highly sophisticated version of a biodynamic compound preparation. The BD Compost Starter seems to best serve the needs of people who have a small amount of organic matter to compost and it is appropriate for the beginner in biodynamics who knows little about the method and wants to get started without worrying about “Am I doing it right”. For more details, please check out the complimentary instructions provided on this website page – BD Preparations: Instructions and Articles. Also, Applied Biodynamics, Issue #6, Winter 1993, offers a lengthy and timeless article on “Pfeiffer’s BD Compost Starter and BD Field Spray.”

Q: Can the preparations be mixed together?

A: It is best to use the preparations separately, especially for the first time they are applied. After the preparations have been applied individually at least once or twice, if time is a limiting factor, earth preparations may be combined. For instance BC may be added to BD#500 during the last twenty minutes of stirring and sprayed out together in the evening. The two silica preparations may be combined the same way and sprayed out at sunrise. One would generally not combine the earth preps with horn silica as they are sprayed out at different times of the day.

Q: In what order should I use the preparations? And what time of day should I apply them?

A: JPI recommends that you get a foundation of all the compost preparations on the soil first in the form of biodynamically treated compost or one of the preparations that contain all of the compost preps.  If you are just starting out and do not have treated compost to apply right away or enough compost, you can use the BC (barrel compost) stirred for twenty minutes, or the Prepared #500 stirred for one hour. Both contain all of the compost preparations within their formulation. You may also use the Pfeiffer BD Field and Garden Spray, which contains all of the compost preparations plus BD#500(horn manure). It must be activated by moistening 8-24 hours ahead of time, but does not require any stirring. This first step increases the effectiveness of all the other preparations.

BD#500(horn manure) is applied next. It is sprayed directly onto the earth at planting time to stimulate seed germination, proliferative growth of roots and microorganisms that result in good humus formation in the soil. It can be used as a seed soak or root soak when transplanting. It is also sprayed to assist the breakdown of green manure crops when they are turned in, and in the fall when garden stubble is turned in. All of the earth or brown preparations that are sprayed on the soil are applied in the late afternoon or early evening when the dew is falling and the earth in breathing in. They are more effective if the soil is moist and has begun to warm a bit, as in spring.

The BD#501(horn silica) is used only after BD#500 has been used.  It is sprayed on annuals after the second or third set of true leaves has emerged, when the plant is 3-6” tall and the roots are well established, and several days to a week or more after transplanting.  Horn silica is sprayed in a fine mist upward into the atmosphere, falling on the foliage to stimulate growth and assimilation processes and photosynthesis. It is stirred and sprayed at sunrise as the earth is breathing out and dew is still present on the leaves before the plants are exposed to strong sunlight, which may cause burning on the foliage. It may also be applied again after blossom set to improve the sweetness and flavor of fruit. Repeated applications may be made through the season if the weather is particularly wet, cold and overcast to bring more sun forces to the plants. Only use when all danger of frost has passed.

Plant silica or BD#508 (Equisetum arvense) tea may be applied to the soil and to plants at the beginning and throughout the season to help prevent detrimental watery influences that could result in fungal plant diseases. It is used more frequently in wet, humid conditions to increase its preventative benefits. It can be applied in the evening to the soil and plants or in the morning on plants. Both the plant and horn silica strengthen the silica processes in the plants helping them become more resistant to insect and fungal attacks.

These are only general recommendations. All of the preparations may be applied more frequently and specific applications have developed over the years. For more detailed directions on the use of the preparations, see “Brief Directions for the Use of Biodynamic Sprays 500, 501 and 508”, in the Fall 2005 Applied Biodynamics, issue no. 50. Some recommendations have changed over the years, For instance, the one-unit portions of BC, 500 or “Prepared” 500 which treat up to an acre should not be divided even if they are being applied to less than one acre. The full one-unit portion should be used no matter how small the area to be treated, to generate enough of a force field to be effective. However, the Pfeiffer Field and Garden Spray may be subdivided in proportion to the amount of land being treated.

Q: What kind of container is recommended for stirring?

A: The most important thing here is applying the biodynamic preparations. If all you have is a plastic bucket, then by all means use it. The ideal container, however, is probably a clay crock, such as you would see we are using here at JPI. Alternative stirring containers would be large glass jars, stainless steel buckets, wooden barrels, food-grade plastic containers (i.e. joint compound buckets). No container that has held harsh or toxic chemicals or substances should be used.

Q: How often should I spray the preps?        

A: Traditionally the preparations have been applied twice a year; for BD#500, once in the spring and again in the fall. BD#501 is applied in late spring and again in early or mid summer. The equisetum prep is applied spring and fall and when excessive wet conditions prevail. With the increase of pollution in the water, air and rain, climate change with more dramatic and unpredictable weather, and the increase of chaos and transition in the world, we are recommending much more frequent application of all of the preparations. More remediation is necessary to counteract the life-destructive forces and to reinforce the vitality of the soil and plants and the whole Earth’s energy field.

Q: Are there times when the preparations should not be applied?

A: Yes, there are times when application of the preparations and working with the soil should be avoided if possible. We recommend that you use the biodynamic planting calendars as a guide to avoid times or days with detrimental cosmic influence on plant growth and germination. Unfavorable times or black out periods are clearly marked in the calendars. The calendars will also guide you as to the best times to augment the forces and effectiveness of the preparations.

Avoid applying preparations right before or during rain or in very windy conditions, as much of the effectiveness may be lost. They should also not be applied in hot, intense sunlight, and preferably not on bone-dry soil. Horn silica (BD#501) should never be used before horn manure (BD#500) has be applied and never before transplanting. It should not be used on young trees, bushes, fruit trees and vines and not until they are of fruit bearing age and only after #500 has been applied several times and the roots are well established as reflected in the growth of the crown. Horn silica should not be used in hot, droughty conditions or when plants are stressed from lack of water.

 Q. What is the better day to use the preps…root, leaf, flower, or fruit?

A. The best days to use the preparations are when you will actually do it, when you have the time, and when the weather is favorable. Specific days may be chosen to enhance the particular crop you are treating. For instance, if you were growing leafy crops, sprays would be applied for greatest benefit when the moon is in front of a water constellation, on leaf days. In a backyard garden with a diversity of close plantings, it is often difficult to spray for specific type of plants. In the beginning of the season, the application of BD#500 on a root/earth day would be beneficial to stimulate strong healthy roots of all the plants needed as a foundation for all future growth. Next for a broad application on a variety of crops, BD#501 may be applied on a leaf/water day to stimulate the silica forces and utilization of forces streaming in from the cosmos and to increase photosynthesis. This will help the plants be more resistant to insect and fungal damage. After blossoming, the application of BD#501 on fruit/fire days will increase the flavor and sweetness of the fruit of plants like tomatoes, beans, squash and all the other fruiting plants.

Both of Maria Thun’s books, Gardening for Life and The Biodynamic Year as well as the Maria Thun Biodynamic Calendar and the Stella Natura Biodynamic Planting Calendar are excellent resources for working with the constellations and choosing specific days for planting, harvesting or applying the preparations to enhance intended results. The article and interview with Sherry Wildfeuer, “Earth, Water, Air, and Fire: Working with the Elements and the Cosmos” in Spring 2013 Applied Biodynamics, issue no. 80, relates Sherry’s experience of working intensely with the application of preparations on specific days to enhance qualities appropriate for the part of the plant being used. Sherry is the creator of the Stella Natura Biodynamic Planting Calendar. All of the above publications are available through JPI.

Through keen observation and paying attention to the rhythms of the day, month, season and year, and the needs and condition of the soil and the plants, you will develop your own sense of when to use the preparations.

Q: I only have a small backyard garden. Should I use a whole unit which treats an entire acre?

A: Biodynamics is predicated on the freedom of the individual user and you are welcome to divide a unit into whatever small portions you wish. However, the preparations should be seen as forces, or carriers of forces, and while no research has been done on the question precisely, we view the unit size as the minimum amount needed to create a proper force field. We therefore suggest that for initial application in particular, that the entire unit be used to treat your garden area no matter how small. Of course, application of excess preparations to lawn areas, shrubbery and trees will be of benefit as well.

Q: How soon may I use my compost after putting the preparations in it?

A: This question has to be answered in accordance with the crop to which you are applying the compost. Tomatoes are a very heavy feeders, and like relatively young, freshly made compost; whereas carrots want compost that is very well aged, up to a year old. Three-week old compost has been applied to tomatoes with good success. Cabbages and other crops want something in between, such as 6 week to 6-month old compost. General biodynamic practices regard compost as being ‘ready’ in 6-8 months. The biodynamic compost made in the fall is applied to the garden areas in the spring, whereas compost made in the spring is applied in the fall.

Q: Is it really necessary to spray BD #501? It seems that the time to do this is just when things are busiest in the garden.

A: YES, it is really necessary to spray BD #501 (Horn Silica). One does not really get the full effect of the biodynamic preparations unless BD #501 is used. The cosmic effects which lead to truly healthy and healthful plants are most stimulated by BD #501.

Q: Regarding storage, how long do I have when I receive the preparations before I must use them?

A: Once you receive the preparations they need to be used within a three-week period or so. If you are unable to use them within this time frame then they need to be stored according to storage guidelines. See JPI handout on “storage of preparations.”

Q: Can I use chlorinated tap water?

A: If you have to use tap water, let the water sit for 24 hours to allow the chlorine in the water to come out.

Q: Can I stir Biodynamic Compound and BD #500 preparations together?

A: It is generally preferred that these be stirred separately. This is especially true the first time that the soil is being treated with the preparations. Thereafter, because the energies or forces are already working, one may choose to stir them together if time is not available to stir them separately.

Sign up for our Emails