Oak bark (505) — a portrait of the calcium preparation

Oak bark (from Quercus robur, the pedunculate oak) is the fourth compost preparation and bears the number 505. In the biodynamic canon it is credited with an ordering role that wards off disease — through its connection with calcium. This portrait sets out the substance, how it works and its special sheath.

Substance and how it works

The chopped bark of the oak is used. Oak bark is rich in calcium-forming forces; in the biodynamic view, the preparation damps down excessive, disordered growth and strengthens resistance to plant diseases. Among the compost preparations, oak bark thus stands for order and defence, while yarrow and dandelion rather mediate the release of substances.

The sheath: a domestic animal's skull

The sheath of the oak bark preparation is a domestic animal's skull. According to Eckard von Wistinghausen, the skulls of cattle, sheep, goats, pigs or horses are suitable. The chopped bark is filled through the foramen magnum into the cranial cavity; protected by the bony skull cap, it undergoes a process of putrefaction. The filled skull matures in a moist environment with water flowing through it — in mud or running water — and is recovered in spring, around the end of April to the beginning of May.

The skulls should be of food quality or approved as fertiliser; sheaths from your own farm or from organic husbandry are recommended. The yearly cycle is shown in the article Making the preparations yourself in autumn.

Use in compost

The oak bark preparation is added in small quantities to the maturing compost — alongside yarrow, chamomile, stinging nettle and dandelion. It brings order to the maturing process and is part of the combined barrel compost.

Frequently asked questions

Which sheath belongs to the oak bark preparation?

A domestic animal's skull — according to Wistinghausen, the skull of cattle, sheep, goats, pigs or horses. The skull cap protects the bark during the process of putrefaction.

What does oak bark stand for in the compost?

For the connection with calcium and for warding off plant diseases; it damps down excessive growth and brings order to the maturing process.