How do you keep weeds out of your food plot, specifically tall grass and ditch weed?

[Jmcd18]

How do you keep weeds out of your food plot, specifically tall grass and ditch weed?

[FirstBubba]

Find your "plot" spot during the winter. Disc, till or plow the spot so that fragile plant growth is exposed to freezing temps. This helps in killing out grasses.
Next, use an all inclusive weed killer like Roundup or 2,4D. Note on the package it will give a waiting period between use and planting.
Also note if the "crop" requires spring, summer or fall seeding.
This won't keep out ALL weeds, but it will help.