OK, now we've planted up my Brooklyn friend's yard. I have 2 questions, based on what I found out by experience regarding her soil and the 2 pesky holly bushes' roots.

The soil was very sticky tenacious clay. By dint of very hard labor by many family members and myself, we managed to chop out an 8 or 9" trench about a large classic digging shovel blade deep. I poured in 2 bags of topsoil into the dug trenches on each side (about 150" long x 8" wide each trench), but wished I'd had my friend buy twice as much topsoil. I just didn't know it was that clay-y. I had wrongly assumed her longtime gardener had amended the soil to make it more friable, but they hadn't. One reason they're her long-time EX-gardeners.

I then raked the clay soil we'd extricated from the extensive fibrous roots of the naughty holly bushes back into the trenches after pouring in 2 bags of topsoil each, and blended the resulting mixture with my trusty T-bar hand tiller. It wasn't deliciously crumbly friable soil as I'd hoped, but it was better than the pure clay.

My Brooklyn friend reports that water does not stand for very long on the garden soil, even after a very hard rain. That would indicate adequate drainage.

I am concerned about those extremely fibrous and extensive holly roots. We hacked the largest ones back with a kitchen knife (sort of like hacking away at the the Kraken's tentacles), but there are still zillions of smaller ones.

What could & should be done about the roots? Should I gently dig up all the hostas & heuchies we planted, put them into a moist plastic bag, remove the soil and then line the trench with some black garden mulch fabric I have laying around my home, then put back the soil & replant everything?