What flowering plants can I plant in our garden in the South Jersey Bay area that will thrive?

Question

We experience flooding of marshy water at times so these should be pretty strong plants I guess.

Answer 1

A garden with no fragrance is like eating a fine meal with a cold. So I always begin with scented plants.

Clethra alnifolia Summersweet, a great plant liking wet soil.
http://www.ces.ncsu.edu/depts/hort/consumer/factsheets/shrubs/clethra_alnifolia.html

Swamp Azalea Viscosum 'Pink Mist'
http://www.ct-botanical-society.org/galleries/rhododendronvisc.html
http://www.ces.ncsu.edu/depts/hort/consumer/factsheets/shrubs/cultivars/rhododen_visco-glauca.html
Mail order http://www.lazyknursery.com/mail_order_catalog_nursery.html

Fringetree
http://www.daytonnursery.com/Encyclopedia/Trees_Shrubs/Chionanthus.htm
http://www.ces.ncsu.edu/depts/hort/consumer/factsheets/trees-new/chionanthus_virginicus.html

Magnolia virginiana Sweetbay Magnolia Sweet Thing'
http://www.sweetthingmagnolia.com/
http://www.magnoliavirginiana.com/

MARSHALLIA grandiflora (Appalachian Barbara’s Buttons) Small, fuzzy, rose to lavender button flowers. For moist to wet soils in sunny locations

Primulas should not be allowed to dry out in the summer. Many grow river side so you may have good luck with these in shade.
Primula denticulata
Primula florindae It will tolerate anything from a moist soil to waterlogged conditions by a pond but can't dry out.. 3 feet tall topped with yellow mop of fragrant bells.
Primula japonica also moist year round. Pink, red and almost purple.
http://www.evermaynursery.com/store/bog-plants.asp
Colored carex would be possible
Carex elata 'Aurea'
http://www.walliscreekwatergarden.com.au/bogplantshade.html
Hosta 'Summer Fragrance' Yes there are fragrant hosta. They should be planted more. Again moist not sodden.
http://www.plantdelights.com/Tony/fraghosta.html

Food Scent Plants-These two like it moist:
Melianthus major smells like peanut butter!! A dramatic shrub with large, bluish, serrated leaves. Kruidjie-roer-my-nie (herb-touch-me-not), Giant honey scented flower.

Answer 2

Check gardenias, azalas, rhododendrums, hostas if in shade, lillies, roses.