Seed germination studies of Vitex agnus-castus^©

INTRODUCTION
Vitex agnus-castus, also known as the chaste tree, is a plant that is grown for its ornamental qualities such as its delicate-textured, aromatic foliage and spikes of lavender flowers that bloom mid- to late-season and attract butterflies. It is also a plant that deer will not eat. Vitex is a shrub that grows 5 to15 ft tall with a spread of 15-20 ft and is winter-hardy to USDA Zone 7. The leaf of this deciduous plant is palmately compound, lanceolate shaped with pinnate venation and is bluish-green to green in color (Gilman and Watson, 1994). The Vitex plant was recently applauded by the nursery industry as a useful landscape plant, however, there are breeding opportunities to improve the ornamental value of this plant (Dirr, 2015). Vitex would benefit from additional breeding in order to develop new characteristics such as a more compact growth habit and additional flower colors.
The long-term goal of this research is to breed and improve Vitex agnus-castus. However, the first part is to understand the seed physiology of this plant. The objective of this research was to determine if there are dormancy requirements for the successful germination of seeds from Vitex agnus-castus (Bewley and Black, 1982).