Nice looking Elkhorn, Lin.
I have ants all the time in my large staghorns. They don't seem to both the plants and they are not the stinging/biting kind. My staghorns are all outside from April through October. The ants seem to love the staghorn ferns. I have never tried cinnamon but it is certainly worth a try. I just either sprinkle a little Orthene behind those basal fronds or mix that powder with water (2 tbs. in a quart) and spray that so that it will get behind the basal fronds where the ants take up residence. In 24 hours (or less) there is not an ant to be found. Ants will either leave very quickly or the Orthene kills them.
Staghorns will take a light freeze as long as it is brief, only a few hours at most. The 'Netherlands' variety will take cold weather even better. That's all I grow now.
