I just recently got the okay to borrow some land from a farmer I know, and once the snow melts I'll be starting an edible garden project. It is a very lush, Scandinavian savannah landscape already (it is normally a semi-wooded sheep pasture), so I have a lot going for me. My goal is to create food value for myself this summer, and long-term to encourage perennial plants that will benefit the sheep, like nitrogen fixers and long-term browsing plants, once I move out and they move back in.
My question is about water. I've seen a lot of talk about swales and ponds, and water retention, in general, makes a lot of sense. My location is just beneath a hill that serves as a sheep pasture and will be getting a lot of runaway nutrients from there, so catching it makes a lot of sense. (Especially since I'm next to the Baltic sea, which isn't exactly doing so hot right now.) But it is a flat location right above the sea level so the natural ground water will be high, it isn't unusual for us to get a lot of rainfall, and I'll be getting the runaway water from that hill I mentioned as well... and if I add swales to that, I am a little bit worried about drowning the land I am trying to take care of. It is already quite green. How much water can a site hold before it becomes counter-productive and damaging to tree roots, for example? And how do I know if I'm there? I have no intention of turning this plot into a swamp, after all...
Companion Planting Guide by World Permaculture Association