Those of us who work with the raku pottery technique participate in one of the most exciting and creative processes. Raku's colors and patterns result from rapid cooling as the pieces are removed from the kiln while still glowing hot; it is this that attracts modern potters to the raku tradition. Due to porosity of the clay body, crackle glaze and extreme heat shock, the raku ware is rendered fragile and is, therefore, not intended to be waterproof. I suggest that you treat the raku work as decorative and that you put a waterproof liner in the pot if you want to use it for flowers or plants. Admire and enjoy!