Following on from my series on compost preparations, this post looks at a ferment preparation that is preventative and curative, BD508 Horsetail Preparation.

What is BD508?

BD508 is a biodynamic preparation also known as Horsetail (Equisetum Arvense) Preparation. It is a ferment or ‘tea’ style preparation that can be applied direct to the soil, plant or atmosphere. Its purpose is to regulate the watery element brought on by too strong or too weak moon forces. By using BD508 one is able to curb the strong moon forces and encourage those forces when they are too weak. It is connected to light, in particular with relation to the role silica plays. It is similar to BD501 Horn Silica in this respect although BD508 Preparation brings more silica than light – in sunny countries such as South Africa there is less need for so much light; indeed this can result in sunburn on vegetation. This is where BD508 is so wonderful and really stimulates the silica role.

Why use BD508?

BD508 Preparation is used to control or limit fungal growth, especially powdery and downy mildew. It is both a preventative and curative preparation in low pressure scenarios.

How is BD508 made?

Traditionally in Europe BD508 Preparation is made with horsetail, which naturally grows where soil is disrupted. It is a herb with long needle-like leaves – an indication of silica which it needs to hold its very angular shape.

In Steiner’s lectures he mentioned that the plants he recommends using are wonderful for their conditions but there would also be other plants in other regions which would be well suited. In Australia they tend to use Sheoak needles to make the BD508. In South Africa we’ve had good results from using Restios (Restionaceae), a perennial, evergreen grassy plant that also has a high silica content. You can clearly see the silica gesture in the form of the leaves.

To make BD508 Preparation the new growth is harvested at the base late spring to mid-summer, on a sunny dry day and dried on racks in the shade. Once dried it is then stored in hessian or paper bags until needed, to make sure there is no chance of mould.

There are two methods for making the preparation:

  1. Tea – add the horsetail to rainwater or stream water and boil covered in a saucepan or pot– use approximately 200-300g dried material in 10l water (If not dried you can use 1 to 1.5Kg in 10l water). Simmer for 20 minutes to an hour then leave for 24 hours to extract the silica.
  2. Fermenting – Bring to the boil and simmer for up to 1 hour, transfer once cool into a barrel or earthenware vessel for around 2 weeks out of sunlight. The preparation should develop a slight sulphur smell once fermented. You can store this ferment in an airtight vessel in the dark for up to 6 months before using.

I prefer the fermentation process as better extraction of silica is obtained from the Restios.

When is BD508 used?

The best time to spray is from sunrise to mid morning because of the preparation’s link to light as with BD 501.

BD508 Preparation is used on specific days within the Luna Calendar, 2 to 3 days before a full moon and following bad weather when the water forces are at their strongest, which is when there is the highest risk of fungal disease.

If there is infestation in the vineyard it is applied to the  foliage for 3 consecutive days to bring water conditions under pressure and bring the Silica influence to the vineyard.  This will be followed by an additional application 7 to 10 days later.

Additionally if you’ve had mildew infestations in the summer then you can apply the preparation directly to the soil in autumn to work on the process in the soil where it overwinters and it will help with the pressure in the following season.

Unlike many biodynamic preparations BD508 Preparation is applied generously; you dilute 1:10 ratio and apply anything from 100 to 300L/Ha depending on the density of the crop.

So this draws the last of the original biodynamic preparation posts to an end. The core of the applications is to get the natural synergies and energies working in the environment; each preparation has a distinct role to play and they should all be used in conjunction with each other to get the full benefit.