We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
The locals know all of the best wild Beach Plum spots, and clean them out before anybody else. I do not think they can be cultivated, but the plants can be bought. Very slow growers. However the rose hips from the beach roses (Rosa rugosa, a native of Asia) also make a delicate jelly.
We have a bunch simmering right now. Lots of recipes online.
A contractor, I found my deceased Mother's book, [i]Beach Botany[i], an illustrated book with a cursive type face and pages on beach plums. I gave it too a woman client raised in Wellfleet and raised on Botany. Then her husband got mad at me. Of course he is a guy who finds merit (utility) in rap (no cap) music. Be careful with those beach plums, they can bring out powerful emotions.