Man, that's almost a trick question :). Can you edge with a trimmer? Sure, lots of pros who run trimmers everyday do it like that. Should you edge with a trimmer? Probably not unless you are a pro who uses a trimmer all the time. There's definitely a learning curve & some skill involved in getting a nice, clean edge & not scalping the grass with a trimmer. Plus, even those pros will often use some type of decicated edger at least once at the start of the year to "cut through" the heavier growth & define the edge of the grass. Then they use the trimmers after that to maintain the edge. If you're a typical homeowner like most of us then I'd recommend a single power head with multiple attachments (at least edger & trimmer). There are several choices out there, depending on what you are looking to spend. Until recently, I had used a Troy-Bilt split shaft trimmer/edeger & it was a trouble free, dependable unit. I never had to do anything maintenance wise & it has the primer bulb which makes it very easy to start. Just a week or so ago I order the Echo PAS 265 power head with the trimmer & edger attachments. I haven't ran it yet to be able to give you any feedback. I looked at the Stihl Kombi system but decided on the Echo because of the positive feedback on other lawncare forums & because they've got a 5 year homeowner warranty on their products. Anway, I'd definitely get an attachment system of some type & stay away from trying to edge with your trimmer unless you are willing to live with some scalped patches until you get the hang of it....Good luck.