Living in southwest Arkansas, Momosa trees were a real trend as far back as I can remember (around 1960). And they are beautiful in bloom. But yes they are a nuisance - the dropped flowers make a mess in the yard (and on cars, lawn furniture, anything outside). Then you have the seed pods, after which plants begin to sprout far and wide beginning the next spring. This property had them around the house back when I was a kid and in 2016 we still have a tree or two somewhere close and end up pulling up sprouting trees in flowerbeds from wind-born (and probably birds) seed. The house I grew up in...same thing, it's like fighting crabgrass if there's a mature tree anywhere in the neighborhood!