Pat,
I'm in the southern part of Maine so what I see may not mirror what you'll see. Last spring I planted 1/2 ac of imperial clover and about 1000 sq' of imperial powerplant. I didn't see deer in the clover until after the first killing frost. Before that the deer were concentrating on that tiny little plot of powerplant. I planted to powerplant around memorial day and it was about a month or more before the deer were in it regularly. It got to be about shoulder high and then the deer found it and mowed it to about 3' high and that's about how it stayed all summer.
The clover really shined for the turkeys. I had 3 hens and about a dozen polts that were constantly out in the plot.
They're cool critters to watch grow. It also was great after the frost killed the power plant and before spring green up. The deer hammers it this spring, eating virtually every bit of green as the snow melted off it.
I don't know what you land layout looks like but if you have another thousand sq' I'd suggest trying something along the lines of Powerplant. By trying a coupld of diffrent seeds you can see what the deer prefer and at what times of year. If you listed to the language and action of the deer they will tell you what they prefer.
As for how soon they'll untilize your plot? It depends if their are other prefered browse for the deer to feed on. If there are none prefered to your plot they'll eat you out of house and home as soon as they locate it.
