It’s hard to say for certain what is happening here but there are a couple of things to think about.

We don’trecommend adding manure when planting. Manure needs to be completely composted and cool and we recommend adding it to your garden in the fall because it can burn young plants. Compost is the best material to add at planting. If the roots are circling in the pot, tease them out  so that they continue to grow outward. Roots tend to keep growing in the direction they are currently moving in and will take the path of least resistance. 

While we haven’t had an exceptionally hot summer this year, a rock bed creates a very warm environment for plants. I see that you live in Anoka and wonder if your Lois is really sandy. If so, you will want to make sure to keep them well watered. 

You also wondered if they are being over-watered. If they are at the end of a  storm drain, that could be a problem. You don’t want to channel water directly on them. 

https://extension.umn.edu/how/planting-and-growing-guides