|Oak bark of Valley oak|
Biodynamic Compost Preparation 505: Oak Bark
This is one of the plants our ranch grows in abundance. Rudolf Steiner specified the bark of Quercus robur, the common oak in Europe, whose substance of bark is about 77% calcium. In United States, the White oak is often used. Our native White oak in the Napa Valley is Quercus lobata, Valley oak. Steiner felt the calcium structure of oak bark provided the ideal form of calcium which gives plants structure and helps them resist disease (Agriculture, 100).
|Oak savannah by garden|
I have always felt a particular affinity to oaks. In the Midwest where I grew up we had large, 500 year old White oaks growing along Mosquito Creek. On our ranch some of the Valley oaks are at least 300 years old. Donald says they are so large we almost stop seeing them.