Hi Kim, I pay attention to Susan Ashworth as do most folks when it comes to seed saving. My spacing is on ten foot centers with caged varieties. This may be somewhat less than optimum for potato leaf varieties but there is a redeeming factor. The potato leaf gene is recessive so any crosses will show up with a regular leaf at the seedling stage. All that is necessary is to plant a few extra seeds and discard any seedlings that come up with regular leaf. I don't grow Pimpinelifollium (sp?) varieties because of the high amount of pollen they release into the air and I don't save seed from double fruits. BTW if anyone is interested in getting somre heirloom seeds they can E mail me direct at the following address with a snail mail address and I'ii send a list of available varieties. ChuckWyatt@compuserve.com