Native plants for a Cape Cod garden

I just added the pink turtlehead to my yard, in a spot where a tree stood just a few weeks ago. The area gets some morning and late afternoon sun. The soil is moist and rich, so Chelone lyonii should do well. The plants also like a good composted leaf mulch, and I will add some homemade mulch once the oaks have shed their leaves. I only have 3 plants as I only found one local vendor who had the native variety. A cultivar, called “hot lips” is more readily available. I hope it will take over the area in the next few years – pink turtlehead tends to spread slowly by rhizomes to form large clumps, and somtimes it self-seeds in moist soils.