Goumi berry bush

Eleagnus multiflora. Finally, a berry bush that is a nitrogen fixer, produces tasty fruit, and is not known for any invasive behaviour. Very productive, goumi bushes produce a profusion of elongated red berries with a slight silvery surface. Hardy to zone 4b, these bushes are an ideal companion in a food forest, providing fertilizer to other fruit trees. The bushes are only 6' tall, and do not spread - making them a great understory plant in a food forest, or a part of a food-producing hedge.

The bushes are said to be either fully or partially self-fertile. They will set lots of fruit without needing a second variety. That said, you might get heavier fruit loads with 2 different varieties. 

The berries contain a single, large seed, and have a complex flavour - sweetness, tartness, and some astringency. We like eating them as-is off the bush, they're great in preserves where their astringency can be reduced. For best flavour, wait until the berries are soft before eating them.