From the Biologic Website...

http://www.mossyoakbiologic.com/products/greenpatchplus.asp

It kind of sounds like it would be tougher to get your plants established in the heat/dry of mid-summer, so it would be better to plant in either the spring or fall. Fall being the time when deer are most attracted to the Green Patch Plus.

Also from the website (click on 'planting guide' at bottom of page)...

"To give your plants the best chance of success, plant with adequate soil moisture, typically early spring and fall planting will be the most successful. You can frost seed or plant in the spring when daytime high temps start to reach 63-65 degrees. Fall plantings should be planted prior to the onset of autumn rains. A good rule of thumb is to make sure your food plots are planted at least 30-45 days prior to the first frost."