Being the old science teacher that I am, I volunteer at the Mark Twain School in west Tulsa to teach science enrichment for the 6th graders there. It's an inner-city school with alot of needs, so I, along with a few others from our church, help out with this about every six weeks. Yesterday as I walked into the school from the parking lot, I noticed how thick and brown their playgroud was, which is a good thing.
Two years ago, the teachers and staff told me that their kids didn't like going outside to play because of the terrible sandbur problem they had on the playground. The prickly seeds would stick to their shoes, socks, clothes, and whatever else they could find to grab on to. If you've even been stuck by one, you know it's not alot of fun. Sandburs are very commone and troublesome in sandy soils, hence the name sandbur I guess. Sand Springs, Bixby, and parts of south Broken Arrow near the river in particular are prone to sandbue problems.
So LawnAmerica decided to start treating the two acres or so of turf at the school on their playground and surrounding turf for no charge, as one of the many "freebies" we do for our community. The problem now is pretty much gone, so the staff has told me several times now how much they and the kids appreciate not having to battle sandburs on the playground anymore. There are no magical solutions to a sandbur problem, but as with all weeds, the best thing to do is properly fertilize, irrigate, and care for the turf in order to build up the density of it. This helps slow down weed germination, and in the case of sandburs, helps to crowd out these pesky weeds with their sticky seeds.
Another key is to apply a spring pre-emergent herbicide, which will help prevent germination of sandburs somewhat. Most products are not as effective on sandburs as they are on crabgrass, but they do help substantially. We used to have a product named MSMA available to use as a post-emergent spray to kill the weed after it germinated and was growing, but that product has been taken off the market. So there are really no other good options available to kill existing sandburs, short of spraying Roundup and killing the surrounding turf also. We have found though that by building up the turf density, along with proper pre-emergent treatments, the problems seem to go away.