Zygotic embryo culture has proven itself an invaluable method in plant science for both pure and applied research. The composition of medium used to sustain embryos is a key to successful culture. Optimal composition of the medium changes during embryonic development; generally, the younger the embryo, the more complex is its nutritional requirements. Feeder cell and "double medium" culture methods have been developed to improve the survival of zygotes and proembryos in vitro. In this chapter, we discuss the nutritional requirements of cultured embryos and the importance of the osmotic environment for nurturing young embryos. Specific methodological adaptations used in the culture of Capsella are outlined to demonstrate how standard protocols can be manipulated to suit one's needs.