We give kale always raw/fresh to our canaries. The love the leaves but also the stems.
Kale can be kept in pots and it is winterheart. So it survives winter temperatures, even snow and like this we always have kale for our canaries throughout the year. Kale is an easy plant and you do not have to worry about pesticides.
Kale contains nutrients that your canary needs.
Yannis and Stella @Apollon, Naxos 