if these would eventually outgrow their role

==>>> you didnt really explain the role ... other than its use as a border ...

size?? .. shape.. etc??? ... what are the space limitations of your application????

i have prunus serrotina.... likely the one you ruled out ... huge trees ....

its a seed sprouting nightmare ... having to kill millions of seedlings with round up every year ... otherwise they are nice trees ...

information for you.. simply suggesting.. the wildlife cant process all the food ... if in fact.. processed ones are also still viable ... if you get my drift ... [if you dont... i have seedlings popping up very far from the actual trees ... which i take to mean.. they move thru the birds digestive track .... in an efficient manner.. dont make me say it... lol]

describe your intended size constraints ....

ken

I have all three species (pennsylvanica, virginiana, and serotina) growing naturally on our farm, and wouldn't want to have any of them in a suburban yard: messy (stains concrete, yard furniture,etc.), too many seedlings, and too large to maintain easily as a hedge. I don't think your neighbors would appreciate your planting any of them.

You might want to look into beach plum, Prunus maritima, which naturally is about 6' tall, though it does sucker, and is popular with critters for food. NHDOT has planted some in in the median of one of the highways near me, so it will grow away from the beach and is salt tolerant. It is adaptable as far as soil, but likes reasonable drainage. I don't know where you live, and I don't know how well this plant adapts to parts of the country beyond New England.

IME, all Prunus are relatively short-lived and disease prone, with black knot and webworms being the two most noticeable issues around here. I don't see a lot of foliage diseases, however. You might want to look at a mixed species hedge so that if disease is an issue, there are other plants to help fill in.