Snapshot is a Pre-emergent that you spread in mulch beds. It has an 8-9 month residual so it is a very effective product. It is rather pricey ($70/bag) which cover about 1/3 of an acre. Go to your local Lesco and they can tell you more specifics.
i am about to do a faily big mulch job this week that has a lot of weeds to bbe pulled. i wanted to put down a pre emergent so it would stay weed free. i was shocked when i called lesco and they told me 70 a bag. how much is treflan a bag?
If you want the beds to stay weed free for 8 weeks (until you get the check) then put down some Lesco Pre-em 0-0-7 at a heavy rate. Put it down before you put down the mulch or else you will have yellow bits of preem everywhere.