Keep It Simple Stoner

Nature tends to maintain a balance.. in a healthy ecosystem all the shit is present... both nutrients and disease... but it is kept in check. Put your plants in an ecosystem that will suit them, where they can compete... not IN the muck where their roots will rot... and not on a rocky shore where they will get no nutrition from the soil... but in a place that supports other similar plants with similar needs. Be aware of soil types and forest types; for example, a hemlock/ beech forest will be on a very acidic substrate and tells you not to grow there. Your lakeshore might be perfect, I don't know, I haven't seen it, but you just have to educate yourself and then let your instinct giude you.