nothing wrong with letting all comers put up signs to avoid any charges of bias and risk alientating potential and current customers. However, and this is a big however, when the flood of local candidates joins the national office seekers, you're going to have a lot of signs on your property. After the campaign, will folks retrieve their signs or will that be your job?

The only issue you may have to contend with is size of signs. If everyone goes along with the typical yard sign, that won't be a problem. But there is almost always one in every crowd who will want to put up a mini billboard. It's your property; you can set the rules regarding size of signs and number, as in one per candidate.