I tried about 40 years ago to grow some crown vetch on a sloping boulevard between our driveway and the street.  I babied that stuff for months but it just didn't/wouldn't grow.  Also it was classified as a "perennial" but it never showed even one sign of coming back the following year.  I was hoping it would at least try to come back and I could baby it along some more and give it more time to spread and grow, but it never did.  Maybe it was just too cold here, I don't know, but it was sold for a zone 3-4 plant, which is what I need.  Haven't tried growing any of it since, and now I live in a different place in a different city. 

Since my stroke last year, I'm going to stick with only flowers and grasses which can be confined to a planter or pot of some sort.  I just don't have the energy to be on my knees pulling weeds.  I might even try a few container veggies, we'll see how much room I end up with.  I have a huge back deck but the light exposure, even in summer, is not very good.  I've always had good luck back there with petunias over the years, and a couple of years ago I had some chives and even one planter full of cucumbers and all of that did just fine.  I'll give it another go this year because I have oodles of organic seeds that I bought from My Patriot Supply a couple of years ago. They have a 5 year in-package expiration so hopefully they will still grow.

https://www.gardeningknowhow.com/garden-how-to/beneficial/groundcover-for-beneficial-insects.htm?goal=0_a3b6094552-656b4c0654-214189657