I have found here in the North East U.S., Vermont specifically, that there are a few factors for food plots to be successful.
To start, If it is a new food plot for deer hunting it may take the summer period to see constant traffic from deer. The deer live in those woods their whole life. They know what is in their area for food, cover, water and safe passage routes. If the new food plot is made away from travel corridors, it may take some time for the deer to figure out a safe way to use it. If they already have ample food sources, they may not search much for new food places. But if the new plot is in the deer's normal travel route, then they will include that plot into their routine. To sum this up, sometimes a plot is untouched in the spring yet devoured in the fall/winter and can be just the opposite.
If your hunting area has a lot of deer than you should plant a bigger plot for viewing in off season/winter food source/deer season destination food source. I use those 1/2 acre plots as hunting plots near buck bedrooms, thick bedding areas to intercept bucks searching for doe's, and staging areas on travel routes. If you plant too small of a community or destination food plot, the deer will chew it down to bits before season gest here. Not to mention the feeding done by turkeys, rabbits, and any other critter that visits. The small hunting plot is to entice deer to pause in a strategic place where you have a stand put up. It gives them something to nibble. But if that area is where most of the deer congregate it needs to be big enough so they cant eat it all or they will just move on to better supply. I have had small hunting plots that after several years being established (5-7 years) I had to vastly expand the 1/2 acre to 3 acres then make a new hunting plot up wind of the now destination plot to intercept the deer. I have planted just about everything available for food plot seed. To show that all plot seed is not the same I will say I have planted three different clover plots, all of different kinds of clover seed, and witnessed deer walking straight through two of the clover plots without so much as a sniff then arriving at the third plot to feed. So sometimes you have to experiment with different types to find what works for your spot.
I also found that offering a different food source than what is already available can prove to be very important. If you have corn on one side, clover on another side, then maybe planting something sweet like sugar beet would create more opportunities to attract deer. If you are surrounded by soy beans and corn maybe planting oats or rye or a brassica may work well. A cheap way to monitor food plot use is to make a few 3 foot around chicken fence cages and place them in the food plots. This will show you how your plot would look if it was never eaten. This little trick will help you determine if you need to expand you plot if it is chewed down to the dirt around the cage or if you should build a plot in a different location or change to a different kind of seed if the deer aren't feeding there much. Maybe the deer don't feel safe in that spot or there is the same kind of food source nearer to their bedding and they feel no need to travel further to get the same feed.
I am a hunting and fishing outfitter and professional guide in Vermont. I am not one to act or talk as though I know everything about the outdoors. So I hope I don't come across that way. I have made thousands of mistakes and will make thousands more I hope. All of this information and suggestions are as a result of those mistakes and have proven to remedy those problems. I hope this helps and if you have any questions send me an email.
Whitetail Strategies Guide Service
Fred Scott Owner/Head Guidewww.whitetailstrategies.net