Ask Mr. Smarty Plants

If you take your cues from Mother Nature you will see many miles of sand dunes along the beaches of the Northeast that are kept in place as a critical part of a dynamic, changing ecosystem with grasses.  Their fibrous root systems are adapted to keeping them in place and extracting the necessary water and nutrients that are present in the sand.

You can create a list of grasses native to Vermont by visiting our Native Plant Database and doing a Combination Search.  Select: Vermont, grasses and sunny conditions.  The list generated has links to detailed information pages with images.  You will find vey few that are as short as you are thinking you would like them to be but again, look at how nature does it.  There is very little that evokes the sense of the beach and summer better that tall grasses moving in the breeze with their flower heads highlighted by the sun.

Planting the plants in the fall is ideal ... the soil is warm and moist enough to promote root growth and the air is not so hot and dry as in high summer. So they will have a chance to get established before winter.  Because I am not certain of your exact conditions I am not sure what to recommend regarding mulch.  If you have a clean, bare sand dune where weeds are not a huge issue, I would say there is no need to mulch.  If it is really just a mound of sandy soil that is full of "weeds", pull them out, plant the grasses and mulch with a nice dark shredded bark mulch (nothing evokes the sense of a strip mall quite like orange mulch!).

Here are some grasses that would not only do the job for you but would be quite attractive when planted in drifts:

Ammophila breviligulata (American beach grass) (this plant can be very aggressive)

Calamagrostis canadensis (Bluejoint)

Hierochloe odorata (Sweetgrass)

Panicum virgatum (Switchgrass)

Schizachyrium scoparium (Little bluestem)

Sorghastrum nutans (Indiangrass)