Easier to dump some well-aerated soil on top and plant in that. Gives the small plants a chance to get established before the maples root into the new soil.

It's usual for it to be bare under Norway maples, you can only get so far with underplanting of these. To have full potential site needs to have the trees removed.

"The larger species, such as Norway, Sugar, Big-leaf and Red Maples, are fast growers (2-3 ft. a year), quickly building shade for a country lane or a large woodland garden of easy lines. For street planting and home gardens, oaks would be a better choice: They deliver big shade nearly as fast as the large maples, are less ready to drop limbs during snow and ice storms, and don't have the maples' dense, shallow, competitive roots"

--G. Schenk, The Complete Shade Gardener

bboy,

My maples are grown and I am trying to avoid removing them. My theory is that I can install root barriers at about 15 ft from the maples and plant on the other side of the barrier. Looking for ideas. Thanks.

John

Depending on how big they are, whacking the roots off - in order to install barriers - at only 15' from the trunks could be

1) A helluvahlotta work

2) Detrimental to the health of the trees

The only time I tried to put a barrier to tree roots, they just came up under them and filled in as usual o the other side. I put mine down about six to eight inches deep.

Now, it was cottonwood/hybrid poplar but, it was enough to convince me against trying root barriers again.

try the search function at the hosta forum .... IT WONT WORK ... period ...

and there are numerous snake oil salesmen that will try to sell you a multitude of remedies ...

think about these things...

first.. the roots can be 2 or 3 times the size of the tree above ground... is 15 feet really outside of that parameter .. if not.. you will fail ... and since the Norway can easily get to 30 to 50 feet... 15 feet from the trunk is not far enough ...

second ... trees are super competitors... and they will win every time... with 1500 hosta under all kinds of trees.. let me tell you from experience.. NOTHING GROWS UNDER A NORWAY [except a billion Norway seedlings] ... and barely anything will grow under the rest of the maple family.. and a few other families of trees .... they will out compete everything under them for all water.. and all nutrients ... they are super machines.. and IMHO ... there is nothing you can do for the long run.. except destroy them ...

third .... absolutely every place you cut it a root .. it will be replaced by hundreds of new feeder roots... sort of setting you back further than you were when you started ...

you can try .... you can break your back.. you can spend thousands of dollars .. but trust me.. the trees will win ...

the one thing that will work .. is growing in pots.. and you still have to move the pots once or twice a year.. or the tree will grow into the pots...

i wish i had other options... but alas .. it is the Norway ...

below is a picture of maple roots [not Norway] from the neighbors house when he had to redo his septic field ... think about your barrier idea .... getting a chance to see what you are up against might help ....

ken

{{gwi:197426}}

Ken,

Thanks for your advice and the picture. I surveyed the area once again after reading your reply. The Norways are mature - 40+ years old. I planted two Stewarties, each about 30 feet away from the Maple; just beyond the drip line. There were some small roots when I dug. Since it is 30 ft away, the root density was not a problem. My theory is that root barriers at about 15-20 ft from the Maple will give the Stewartias a chance to get established; perhaps for 5 years. If the Stewartias really struggle sometime down the road I can decide to take out the Maple. This will retain the shade I get from the Maple for some years at least. Obviously, I am thinking I can have my cake and eat it too - for sometime. It maybe a losing battle eventally. But since I am planting beyond the Maple's drip line, I am hoping that the plan will work at least for some years. Your email certainly will make me think twice. I have till early spring to decide on a course of action.

John

For the root barrier to do any good for even 5 years, it's going to have to be pretty deep (depth depends on soil type, moisture conditions, etc). Why go to all that work for little, or possibly negative, payoff? What are you going to do after 5 years when the tree wins and comes back into the area with a vengeance because of its root pruning.

I have a large Norway about 40 feet due south from the house. It provides a lot of shade in the summer. Neverthless, it is being cut down on Friday! Along with another Norway maple in the backyard that is larger.

I was torn about cutting this tree down because it will make the south side of the house hotter in the summer. But I have come to really dislike Norways. They are extremely invasive and it is particularly difficult to grow anything under them. They have very aggressive canopies that will outcompete any other canopy tree growing around them. I would rather get some sun-blocking shades for the windows and be able to plant a decent shrub border, maybe a nice native tree or two that doesn't grow quite so large.

You might try limbing up the Norway, thinning out the canopy, and giving your Stewartias extra mulch, compost, and watering to help get them established. But ultimately, the Norway will make it nearly impossible to grow anything else underneath the canopy or even close by.

Medamana, since you're willing, ultimately, to remove the Norways, and understanding that you're trying to give the Stewartias and others a chance to get started, you could probably, with considerable effort, remove the maple roots in a large circumference around each plant. Use ax and mattocks, even the folding saws that are available now with the good tri-edged blades. You should not endanger the stability of the maples enough to create a hazard that way. This, combined with a barrier 'could' get you where you want to go. There are galvanized metal barriers and also, herbicide-impregnated types. You'll have to see what's available in your area. Otherwise as others have already stated, this is pretty much futile in the long run. Maples generally are VERY good at colonizing their site. I've got an enormous silver maple in my backyard and hostas planted anywhere near it fail within a few seasons. They don't grow larger but shrink a little each year.

Anyway, more fully understanding what you're trying to do, I think you could achieve some degree of success, as long as you keep your expectations modest!

+oM

I really appreciate the excellent points of view from everyone who commented on my question. Very useful. I have 3-4 months to ponder on the decision.

John

Hi John -- I know it has been 12 years now -- if you happen to see my message, could you let me know how it went? I'm considering using root barrier to shield some new plants from the surface roots of a mature silver maple.

That's for sure... Thanks for the reply!