Ask Mr. Smarty Plants

The bayberry, Morella pensylvanica (Northern bayberry) you are thinking of is a good sized plant for your situation and is a real icon of the Atlantic seashore. 

In its native habitat it grows in very sandy soil in places close to water where there is ground water for its roots, but it will tolerate a wide range of soil moisture conditions.  It responds well to pruning, so you should have no trouble keeping it the size you desire and shaping it like a small mutli-stemmed tree.  Keep in mind that it is a dioeceous plant, which means that if you want berries, you need to be sure to purchase a female (and there needs to be a male within the distance a pollinating insect can fly: probably not a problem on the Jersey Shore!)

You can generate lists of small trees or large shrubs that are native to your area by visiting our Native Plant Database and doing a Combination Search.  Select: New Jersey/tree or shrub/sunny/dry conditions and size 6-12 ft (and/or 12-36 ft).  The plant names on the lists are linked to more detailed information pages about each.  If you play with Narrow Your Search by changing the variables (like moisture requirements), you will see your choices expand and contract.  You may find one that is more "ornamental" than bayberry.  Depending on how far you are from the beach, salt spray may not be an issue.

In that case, you might consider:

Small trees

Amelanchier laevis (Allegheny service-berry)

Asimina triloba (Pawpaw)

Sorbus americana (American mountain ash) (be absolutely certain you do not buy the European plant by accident)

Large shrubs

Amorpha fruticosa (Indigo bush)

Clethra alnifolia (Coastal sweet pepperbush)

Viburnum dentatum (Southern arrowwood)

Here are some photos from our image gallery:

Morella pensylvanica

Morella pensylvanica

Amelanchier laevis

Asimina triloba

Sorbus americana

Amorpha fruticosa

Clethra alnifolia

Viburnum dentatum