Not just in soil. To illuminate: During Miami Beach’s Art Deco heyday, hotel centerpieces and other lavish floral designs frequently, and commonly contained cut crotons in lieu of flowers. Their interesting leaf shapes and unusual color combinations were irresistible to one retired florist we know. In order to keep them looking as fresh and perky as their companions in the vase, she recounted having to first immerse the selections in a bathtub full of water for 24 hours to accomplish it.
Plants love high-quality palm fertilizers which contain micro nutrients—in short, of the chemically rendered (as contrasted with bio-derived) fertilizers, palm fertilizer is the Rolls Royce of garden fertilizers for all ornamental plants. Compare it to you and me taking high-quality, health food brand nutritional supplements versus a cheaply-made daily vitamin of poor or dubious quality.
The last 4 letters of these brands usually end in C-O-T-E. Unless so-formulated, regular in-ground products tend to be absorbed too quickly and burn the roots of potted plants.
Especially cotton and other absorbent textiles. Unless it's sap-drenched shiny polyester and other petroleum-based clothing often escapes untainted. Once marked however, nothing on earth will remove the brown stains. When actively gardening/ working with Crotons, we recommend putting away your Hermès ties and scarves, and dressing down in old, torn, ill-fitting schmattahs ready for the dumpster. If need be, and crotons are handled gingerly, with nothing more than a weakly attached leaf breaking off on your clothing, your garment will likely survive the scourge!
Croton seed has pungent and exceedingly toxic properties, and is associated with the Lung, Stomach and Large Intestine meridians, based on the principles of traditional Chinese medicine. Its main functions--we are told--are to move cold downward, to transform water, and to resolve phlegm.
Well, it depends who you talk to. When I was a small child growing up on the island of Jamaica, I ate (chewed and swallowed) some poinsettia stems and leaves (a Euphorbia related first cousin to Codiaeum var.) which had no effect whatsoever on me. Nevertheless, after observing how the sap can irritate and burn topically on skin, perhaps I was just lucky. Children too young to know better should definitely be kept away from doing what I did so long ago, and the same is true of dogs and bunny rabbits. After a munch or two most animals will turn away because they don't like the taste of the shrub's sap. My understanding is that mouth burns, and upchucking are normally the extent of harm that comes to most canines. That said, to be on the safe side you are advised to seek medical attention right away if you suspect a child or a pet may have sampled any part of a Croton plant, or for that matter, ANY PART OF ANY PLANT in your garden other than plant parts known with certainty to be safely edible.