I planted 4 weeping willow trees about 4 years ago, one died because it was shaded by the reed canary grass and was flooded not long after planting. Two of the others were planted just a few inches higher than the one that died, one has been VERY happy the whole time, another I accidentally mowed with the brush hog when it was about a year old, the biggest one is about 20' tall now and 10' diameter with a 6" or so trunk, the one I ran over is only about 5' shorter but similar in build. The last one is about 2' higher elevation compared to the water and 50' further away from the wetland area, is maybe 10' tall and scrawny, I finally took the support stick off last year where the other two were ahead by a year.
I've lived where there were weeping willow trees close to plumbing, not good, here they're hopefully going to drown out the reed canary grass and give the dirt some structure. I have a few different kinds of willow, one I pulled earlier this year since it died over winter, it had 11 rings at the base, 10" trunk and maybe 20' tall. The other two kinds are much healthier than that one was... I'm going to try to spread some more weeping willows around where the reed canary is worst...