I have an area thats about 3/4 to 1 acre of land, a common area, that is surrounded by 6 units. Recently puchased the properties, and it's covered in massive amounts of goat heads, or puncturevines. This spring I plan to steralize, or I know that they are easily smothered by growing sage grass or bunch grass in the area. My question is, how do I get rid of the seeds? The seeds are the spiked little things that get stuck in your shoes, tires, feet, pets feet, everywhere! I've even had some tennants take their dogs to the vet to remove bad ones, and this property has them worse than I've ever seen. Mainly all over the driveways and walkways. I can control the new ones from coming in, but how do I get rid of the old ones?