These are great suggestions, and a beautiful garden, by the way. I'll have to check the hardiness zone on the carex morrowii. I'm keen on the hellebores, but so far haven't had success with them. It never would have occurred to me to try them in that space.

Thank you.
Gary

in my experience, water is a crucial factor. You probably will always find plants that tolarate the root competion, but they will need water.

The great thing about Carex Ice dancer is its spreading growth, by rhizomes/ underground if I remember correctly. I kept some Carex morowii Variegata (clumping) in my last garden. It did great at the base of a Pseudotsuga menziesii/ Douglas fir, but the plants didn`t get any direct sun in winter which would kill them off.

Wild strawberries (Fragaria vesca) could work, so could Duchesnea indica/ Faux wild strawberry.

or Galium odoratum/ sweet woodruff. I dont`t know whether there are neophyte issues with any of those.
bye, Lin

Geranium macrorhizum--big root geranium--is a classic plant for dry shade.

I grow C. Ice Dance here, so you may well be able to grow it. I do find that the voles love it as winter food, however, so if that is an issue, consider that it looks fairly ratty come spring until new growth fills in some of what was noshed on under the snow.

This post was edited by nhbabs on Fri, Feb 14, 14 at 21:03

Before posting the suggestions mentioned above I checked my book 'Perennials for Every Purpose' by Larry Hodgson to determine their hardiness zones. All are reputed hardy to Zone 3.

Hellebore/Lenten rose is tough as nails but it takes several years to get established. I purchased all my cultivars (including 'Regal Ruffles' & 'Cinnamon Snow') from Santa Rosa Gardens and they've slowly grown to impressive plants on the eastern edge of my garden beds.

The Carex morrowii/variegated Japanese sedge grass 'Ice Dance' divisions pictured above have all expanded to the point they completely cover/overshadow the lady's mantle growing between them. I foolishly (well, out of ignorance) planted both perennials 20 inches apart, assuming they'd eventually fill in and present an attractive edging to the bed I refer to as the Burgess Slope. (The bed is actually planted on my ND neighbor's property but since he enthusiastically dug the holes for me to plant things, I'm guessing he's okay with how it looks.) The sedge grass filled in long before the lady's mantle had a chance to catch up.

{{gwi:196300}}

under a couple of quite large arborvitaes..... The soil is of course riddled with the A's root system

==>>> have you even tried digging under them ...??? if you cant.. try sharpening yoru shovel ....

when you take a very mature .. dense root system.. for an existing tree .. of which conifers are ... and somehow dig into that root mass ...

it will become very aggressive in growing new feeder roots where you cleaned out.. and fluffed up the soil ...

on top of that.. when you water.. to try to plant a new plant there ... you will be encouraging the tree ... probably more than the new plant ...

take this from a hardcore hosta guy.. who has tried to plant under all kinds of trees...

when you do find something... near bare root it.. plant it in the native soil you dug out and cleaned.. NEVER fertilize it [that will encourage the tree] ... and broadcast enough water.. so that you water the whole root mass of what you planted ... not just the plant or again.. you will encourage the tree to infiltrate the hole ... and water deep enough ... for the new plant to survive .. not just shooting it with the hand held ...

it will be hard.. but it can be done.. IF ... you can maintain water.. until the plant can survive .. it really has nothing to do with what plant.. as much as how you keep it watered.. to get it established ..

ken

Well, these are all great responses to my question! Thank you so much.

Gary

I have a friend who couldn't get anything to grow under his mature arborvitae and I gave him some divisions of Epimedium rubrum which have not only taken hold under the trees, they have spread nicely. It is a groundcover that can take the drought in the summer and also deal with shade and tree roots. As a bonus is has early spring flowers that bloom around daffodil time. Ken is right about planting under trees, don't try cutting out the tree's roots to plant something - it only stimulates the roots to grow back quickly. If you hit an extra thick 'rooty' spot while digging, don't chop at the spot to plant something, just try another spot to dig a hole to plant in.
Epimedium is sometimes called 'Barrenwort" probably because it can grow in fairly barren looking areas where not much else grows.

Ken is right about planting under trees, don't try cutting out the tree's roots to plant something - it only stimulates the roots to grow back quickly.

Merely for comparison/contrast purposes, I designed a gardenbed that curved along the edges of my driveway and a granite walkway, under the branches of a mature crabapple tree. I struggled to dig planting holes for the perennials I envisioned adding a softening effect to contrast with the hardscaping. I got frustrated whenever I encountered a tree root blocking a planting hole...until my senior/mature gardening neighbor pointed out that the tree wasn't dependent upon that one root for its survival. Judging by the health of my garden many years later, he apparently knew what he was talking about.

{{gwi:196301}}

The bed is nearly 100% filled in since the above photo was taken a half dozen years ago.