Cattails, yarrow and willows will grow in wet soil. It is possible to set up a grey water system and have your marsh do the processing.

Oaks.

Bamboo needs little to no cultivation. Look for both food and structural varieties. For some varieties keeping them under control is the biggest bother.

The new resistant chestnuts. These were a staple for wildlife and humans alike before the blight hit.

I don't know for sure but I have been told that onions, potatoes and carrots can be planted and allowed to go wild or minimally cultivated and will remain a reserve for many years.

Aloe can be let go in well drained soils.

Fruit and nut trees.