"Valerian surrounds the plant life with a warm mantle.” – Manfred Klett
Fermented Valerian blossoms (Valeriana officinalis), BD# 507 has been shown to protect blossoming fruiting trees and plants from late frost in the spring as well as from early frost in the fall.
In his landmark work, Principles of Biodynamic Spray and Compost Preparations, Manfred Klett explains that the diluted juice of valerian has the faculty to create a sheath of warmth wherever it is sprayed.
Directions: Spray in the evening of predicted frost and again early in the morning for heavy frost. One unit (21 drops) stirred in 3 gallons of warm water for 15 minutes will treat up to an an acre. A partial unit may be used for smaller area.
BD #507, which is also included in the Biodynamic Compost Set, will help to stimulate compost so that phosphorus components will be properly used by the soil.
Directions: Use in conjunction with the other preparations in the compost set.
To learn more about making and using BD #507, you will want to check out these complimentary articles from JPI's periodical, Applied Biodynamics:
BD #507 Prepared Valerian: The Secret of Finished Compost AB 2001 (BD #507 as a compost prep)
BD #507 Using Valerian The Way Steiner Indicated AB 2003-04 (BD #507 for frost protection)
BD #507 Response to The Valerian Prep Revisited AB 2014 (BD #507 as a compost prep)