Move what is currently there to a more suitable, rootless location and replace with a shade tolerant groundcover. They tend to be quite shallowly rooted compared to shrubs and perennials and should coexist with the arbs easily.

Thanks, but I am kind of hung up on making this work, even if it isn't perfect. It's the front of my house and I have worked hard to put this together. I do have ground cover plants like sweet woodruff, and yes, they do grow well there. But I have the other plants that need extra help. I think a barrier of some kind would help, but I am not sure how to do it.

You could install a root barrier between the arbs and the other plants but how easy or successful that may be will be dependent on how long the arbs have been established, how close the other plants are and how much root damage may be encountered.

If you decide to do it, wait until fall.

any chance at a pic??

i suspect you are trying to garden too close to mature trees.. and frankly .... trees ALWAYS win ...

and you arent going to win.. just ask anyone in the hosta forum..who tries to garden under trees... they are super competitors.. and they always.. eventually win ...

burying pots only works.. if you lift the pot out of the ground.. as often as the tree roots grow into the pot...

trees seek water.. so if you water only the pots.. guess where the trees will go..

double down on that.. if you fert the pots ...

you probably.. if you had the space.. need to move out about 3 feet from the trees.. and start new beds out there.. but even then. the trees will invade that...

pots on top the ground will work. as long as you move those once in a while.. as the tree will grow up into those also ...

good luck ..... youll need it. .

ken

ps: maples are the worst ...

Thanks Ken. Here is a picture. I don't expect a perfect solution, I only want to give my plants a bit of an edge that they don't have now. I would only try to protect some of the more vulnerable plants and let the others fend for themselves. The hostas actually are doing very well. They don't seem bothered at all. Maybe pots are the way to go for the astilbe and a few others. BTW, this is my entire front lawn! It's a very small area and there is no place to move anything to. Growing grass here was much worse. So, at any rate I am ahead of the game.

I don't see any problem.

Looks are deceiving! They need constant watering, and many plants are stunted and put out flower stalks which wilt before opening. When I dig up a plant to be moved, I can see that its roots are being choked by the arborvitae roots and it's having trouble taking up water. Some plants are sturdy enough to handle the invasion, but others are severely weakened.