Native plants for a Cape Cod garden

It may be winter and the soil may be frozen, but I find this to be one of the busiest times of the year if you’re into plants.  I find myself pacing the yard already and making guesses on whether such-and-such plant will appear in a few short months.  Now is the time to think about reasons why it may not.  Is it the location, the species, or just bad luck?  Will I give it another chance or will I introduce something else?  How will a new plant affect the other species, the color scheme I had in mind, or any assumptions I had about height?  Nature will randomize but I find that I cannot:  I need a plan.  I am two years into this native plant adventure and I find myself peering over spreadsheets of data regarding bloom times, light, water and soil requirements, and notes on observations I made at the time.  It is necessary work though.  For two years I have been planting and seeding.  This coming year I will either be finetuning or tending to chaos.  There will be battles fought in the yard – some plants will dominate, and others may give way.  Territorial lines will shift and flowers will escape their beds.  I may add a plant here and there, but most of the players are on the field already.  I hope to spend most of the spring and summer observing and enjoying their game.