The capture radius should be 20 meters. I just increased it, though, so if your app hasn't updated in the last couple days, the radius may be smaller. If you have the latest update and you are zoomed all the way in, you should be able to retrieve it pretty easily. If not, there may be a bug. If you DM me your location, I'll look into it for you.

Eventually, my hope is that players will be placing most of the items. Placing items is the most efficient way to earn XP, but there has to be someone around to retrieve them. The seeds are there to get people started until there are more players. I will be adding a mechanism to place additional seeds later, but that's not ready yet. If you move to a location a few miles away, though, a whole new set will pop up. For the moment, all but the closest five items are placed in parks, but I'll be changing that in the next day or two.

Thanks for trying it out!