Not that I am aware-probably taste horrible anyway-but like all garden plants-education is the key-children need to learn that you don't/cant eat everything
If you start penstemon seeds off now or next week, they will flower this year. I did loads last year and they were still flowering in the winter. The green is still there now.
In the US, where penstemons originate, deer forage on them and, as far as I have been able to discover, they are not listed as poisonous in the various indexes of poisonous plants. As an ex-teacher myself, I fully understand Vonmarr's caution. Life could be very unpleasant for any school personnel who could be held to have caused the poisoning of a child, however, many warnings were given to that child.