I've seen the surface root layout of some big Norways, and they just meld together where I think it's no real issue for them. Kinda like the way sugar maples, beeches and some oaks like pin oak do it. So not sure it would "help" anything. Still, I'd think that what you plan would not really hurt them either. I have done some girdling root work on some sizable Norway maples where the overlying root was definitely not melding into the beneath roots, but that work really didn't require any major digging into the soil.

Planting beds anywhere near large aggressive tree specimens will be an ongoing battle. The bigger the tree the worse it will become.

If you don't mind doing the root pruning every couple of years, then it's up to you but if it were me, I'd come up with a plan where the beds are further away and even then, feeder roots will always be expanding, searching for moisture and nutrients.

I've seen beds abandoned for this very reason and the trees were much smaller jack pines.

Not trying to discourage you but it may be time to 'Think outside the box'.

It may be more work initially to change things but in the long run you'll be glad you did.

" I've seen beds abandoned for this very reason and the trees were much smaller jack pines. "

Fascinating. Before this experience, I wouldn't have lumped Norway Spruce into a category of 'trees with very aggressive root systems' but it definitely seems to be the case. To contrast, my very very first rhododendron bed was under a hemlock (in the native soil and grade) and the plants grew just fine.

I can't explain it. ;-)

In the realm of 'Outside the box' would be large pots or planters that contain the roots, in those trouble areas.

Thanks but rhododendrons would never do well in containers around here, nevermind the additional attention they would need in terms of watering. Everything about my garden is designed to let me be as lazy as possible!

I'm probably just going to do it, unless someone comes along with a report of 'oh, Norway spruces like to drop dead if their roots are too disturbed'. As Ben and Bill noted, it might only be a temporary fix; but a mature rhododendron can have a pretty tough root system too, where happy. I think once they get established they will be able to fend for themselves, they are just having trouble getting established when fighting with the spruce roots.

' Everything about my garden is designed to let me be as lazy as possible! '

My goal also. :-)

FWIW: I've read something about Hemlocks being a fibrous root system. Which may be what's different between that and the Pine family(?). Betula (birch) is another tree with what is considered fibrous root systems. But I'm aiming in the dark here.

In my neck of the woods, everywhere (in sandy soil) where I see spruce and pine growing, there is a perimeter several feet out from the trunk, the trees have sucked the soil dry of moisture and possibly of nutrients(?), starting at the trunk out beyond the drip line, so the ground is bare in that area, except for some moss.

But you know your area best and with plentiful moisture out there, you have a better chance of success.

I don't think your trees will die from root pruning, but I've always been under the idea that root pruning is best done in the Fall when the tree is not actively growing.

I don't think your trees will die from root pruning, but I've always been under the idea that root pruning is best done in the Fall when the tree is not actively growing.

Yep, that's exactly why I'm planning it now.

" Perhaps cultivars "lose" some of their natural competitive ability? " It's entirely possible. There's a hybridizer I have met on Long Island, I have a few of his plants. They are beautiful but the interesting thing about them is I know he heavily fertilized his garden. His rhodos have needed way more fertilizer to perform than most of my cultivars. (which is next to nothing, for most of them) So in my opinion he was selecting for plants that performed well under a regular feeding regime.