According to Wikipedia, morning glory is a common name for over 1,000 species of flowering plants. I was researching whether morning glories are native to New York because I see them everywhere. What I did find out about these Ipomoea purpurea (this might be what mine are, but there are numerous species) is that they reseed easily, so, although they are an annual they easily come back year after year.
This is my DIY planter box beautifier. Some zig-zaggy twines for my buongiorno glories to climb. You can easily make this yourself with some twine, wire nails, a hammer and scissors. Make fun shapes or spell a word... something creative. I think this will make my garden boxes pretty, but beware of the nail heads jutting out - I hammered mine flat against the wood but they are still a little dangerous.
I just read a really intense thread on Morning Glories vs. Field Bindweed. Field bindweed is an invasive plant that hurts crops. "Biological controls" were used to combat this conceivably destructive plant, meaning a moth was imported and released to kill this invasive plant. What a horrible idea...We have a problem with a non-native plant so we bring in a non-native moth to make our problems down the road worse. Awesome planning guys.
I'm going to go out on a limb here and say that whatever is growing in my urban garden is a) not toxic to grazing animals (because I don't have any) and b) isn't affecting any farmers crops. Whew! So, I guess I don't have to worry too much. If you want to take a look at the thread, you can read it here.