I know pyrocanthus has thorns and it grows in sandy beach environments.
What about century plants and their relatives?
Good luck!
Barb

Dear dor476 -
Maybe erect a "silent" fence for the dobies, and start researching plants for groundcover and erosion control, such as:
Where there is Sun:

Groundcovers:
Cerastium tomentosum (Snow-in-Summer)
Vinca
Artemesia (Dusty Miller)
short grasses like Festuca (Blue Fescue)
shorter ground-hugging Sedums, ground Phlox, and Ajuga
Veronica repens
Lamium sp. (in shade)
Alyssum saxatile ("Basket of Gold")
Low Âgrowing Botanical Tulips: Tardiva, etc.

Larger plants for anchoring the eye and the are:
Panicum (grasses)
Solidago (Goldenrod)
Rudbeckia (Black-eyed Susan)
Yucca
Hemerocallis (in a "ribbon")

Small trees, shrubs, and evergreens such as:
Ilex glabra ÂnigraÂ(Inkberry)
Bayberry
Rugosa Roses
Juniper (Juniperus noris ÂLime GlowÂ)
Crambe maritima (Sea Kale)
Pinus thunbergiana (Japanese Black Pine)
Pinus nigra (Austrian Black Pine)
Sumac, Rhus ÂLow GroÂ
Hydrangea arborescens. This Hydrangea has a suckering habit (good for erosion control), and 5-6" flower panicles, but itÂs hard to find in the trade.

Plants that are tolerant of drought:
Salvia officinalis ÂRachelÂs Gold & ÂPagonaÂ
Dianthus ÂBrilliant StarÂ
Zebrinus ÂLittle ZebraÂ
Potentilla ÂPimentoÂ
Rosa ÂKnockoutÂ
Sedum ÂAutumn SpireÂ
Knautia ÂMorris MidgetÂ
Hope this helps, as all or most of these will live in your zone.
Best,
PP