Never too early to build a ground blind. The deer will learn to disregard it, so long as it remains unoccupied through the summer. Be sneaky, so that people don't get the idea that this is actually a man-made blind... they like to sit in these. Then touch it up a couple of weeks before the season and surprise them on opening day.
Keep an eye out for sign. I mean human sign. Buggers show up ANYWHERE and will steal used Kleenex just because they can. If you have the kind of stands that you put a bracket in the tree and carry your stand in later, yeah. But don't leave your stands out there all summer. At worst, you will get ripped off, or (OW!) someone will hunt the place because your stand showed them the logic of the location. The feelings of violation, both of your property and your special place, and the deer, will be hard to swallow.
Killdeer