I have watched my sister plant rhodies and azaleas on a berm she made for the purpose in front of her neighbor's norway maples. She has paid to remove half of the maples so there are now only three, about twelve feet apart. Their canopies spread to take up the slack and their roots invade the berm. The rhodies all eventually fail, while the azaleas manage to hang on, though small. Based on her experience, I would be prepared to either care for your rhodies with as much attention as container plants, or address the tree issue.

Hello,

Thank you both for your responses. I appreciate the perspectives you've offered.

I have to admit, I did anticipate your views for the most part, in that as many maples as possible should go. And, I think I'll try to see what can still be removed feasibly. Even some of these "smaller" maples, however, are 50+ feet tall, having grown tall and narrow and are a bit of a challenge to fell, particularly since I've planted around them already.

I have two questions, though. First, would you say the main issue with the Norway maple is root invasion or is it the density of their canopy and thus the lack of sun and precipitation that creates? The reason I ask is some of these smaller maples have extremely high branching (25-30 ft. up), and I have in most areas full morning sun and then an hour or so of intense late day sun through these high branching trees (as it is open fields after this narrow width of woods). In fact, in some areas, I worry if this late day sun is not too hot for the rhodos. This is also why I am uncertain if removing more maples would possibly open up too much light, considering any supplemental planting might take years to achieve similar coverage.

Secondly, and on a related note, what then would you consider acceptable density for these maples in relation to the rhododendron? Kitasei, you mention your sister still struggling with 12 ft spacing, as the trees merely fill in the space. Yet, I have some Norway maples on the perimeter with canopies of 40+ feet probably. To avoid a similar situation in the future would require trees to be 60-80 ft away from each other, which doesn't seem possible for me to do. Akamaingrower, perhaps you can tell me, now that you've removed seven larger trees with great results what your current maple spacing and rhodo distance is. And also, if you believe the improvement is mostly a result of the additional sunlight.

I apologize if I seem to be splitting hairs, as the simplest answer is less maples will be more in this situation. But, as I've said, I've removed quite a few already, probably over 10 of varying size (mostly 6-10+ inches), and I just want to make sure I'm not going overboard.

Thank you again.

Joe

I should have mentioned that my sister also limbed up the norways. The lowest branches were at least 40 feet. I would guess that the rhodies were planted about 15 feet from the trunks.

It is most likely competition from the aggressively spreading maples roots and not lack of sunlight. Here in the PNW, our native rhodies grow in rather heavily shaded woodlands dominated by large conifers. And quite a few bigleaf maple - also natives :-) More sun will of course produce better flowering and less legginess but that is not the issue.

The issue is that the surface oriented and very dense roots of the Norways (also red, sugar and silver maples) outcompete other, smaller plants for necessary soil moisture and nutrients. Establishing any kind of shrub or smaller growing plant in close proximity is difficult. It can be done, but requires far more care and attention to the smaller shrubs and plants for a much longer period than if they were planted somewhere free of the competition.

Every gardening site is somewhat different, but in general I would agree with gardengal that the maple roots are the biggest problem. The seven trees I had removed were extremely large - all had a trunk diameter of at least two feet, the biggest more than three feet. Removing them let in a great deal more sun and eliminated a huge amount of root competition. Which factor was more important is impossible to say. Last summer was the first full season without the maples and was much hotter and drier than a normal summer. This, too, was a factor in an unusually heavy bud set.

We all garden on the site we have rather than the one we may wish we had. My less than an acre is very steep with granite ledge close to the surface in many places. I've planted rhododendrons where they fit - sometimes within a foot or two of a maple's trunk. Extra water, careful attention to fertilizer and mulching are necessary, but the rhododendrons survive - some were planted 25 to 30 years ago. Tall trees a distance away from plantings can provide needed afternoon shade in climates warmer than mine, but I still think you'd be better off eliminating all the Norway maples you can. How difficult and expensive this may be has a good deal to do with access to your site. If a boom truck can get close enough to the trees, cutting down tall skinny ones piece by piece is not all that difficult. Once the truck and crew are on site, removing several trees may not be a great deal more expensive than removing two or three. If the trees can be felled after some basic limbing and cut up on the ground, the whole process goes faster and is usually cheaper. This latter requires a highly skilled climber and feller, abilities becoming rare in our mechanized age.

Is it possible that the rhodies could do better close to the trunk rather than farther out toward the dripline?

kitasei: It's a good question and logic would.seem to suggest fewer feeder roots closer to the trunk, therefore a better chance of success. However... Some years ago my wife placed shade tolerant plants in pots then arranged them in a circle around a large Norway maple. The pots were actually touching the tree. By late July or early August the maple had sent roots up through the drainage holes and filled about a quarter to a third of each pot. I've also seen Norway maple roots completely clog a drain pipe four feet below grade and no more than a foot from the trunk.

Thank you for all your perspectives.

I have to second that growing closer to the trunks of these trees probably won't be any better. One of the original factors in my starting to research and think about this issue was seeing what happened to some soil that got kicked around a few mature Norway maples (2-3ft caliper). The tree sent such a dense network of roots up into it; it was quite eye-opening.

Anyway, I'll take a further look into what can and cannot be removed at this point. So far, I've been planting here and there, leaving open the possibility of still felling a few more. And, at this point I believe I can still handle a few of these. I'd hate to wait to have to pay someone an arm and leg a few years from now to do the same. Some, though, will have to remain on the perimeters, as they are past the property line and so beyond my control. We are still talking only 30 or so feet away from some of my plantings, but as you've said, Akamainegrower, we have to work with what we have, and perhaps with more attention, I can overcome the issue where necessary.

As far as replacement trees to plant, what would be suitable? Anything deep rooting, simply? I have a few red oak saplings. What about white pine? A local preserve has our Eastern white pine, with a lot of understorey trees and plants growing nicely. How would American Holly fair in vicinity to the maples? As a tree, will it hold its own better against neighboring maples (say, at the edges of their dripline) than the weaker rhodos? I have a fair amount of hollies I could use, and I like how they complement the rhododendron.

Thanks again.

Joe

Joe: Books with excellent and extensive discussions of trees (and shrubs) that do well with rhododendrons: The Complete Shade Gardener by George Schenk (American), The Cultivation of Rhododendrons by Peter Cox (British) and Success with Rhododendrons and Azaleas by George Reilly (American). These are older books but well worth seeking out.

i feel for you op. I live in Lindenhurst LI and just planted a bunch of rodies and azaelas under mostly Norway maples. Think enough light gets through [limbs are up high] but not sure how roots will interact. I'm in a low area, theres a stream around property im hoping its wet enough to keep both happy.

Thank you, Akamainegrower, I'll look into those books. My local library might even have them in stock. I recall there being a few books on shade gardening.

JPM995, maybe the stream will keep the roots directed that way, and less vigorously toward the new plantings.

As a additional note, I was cleaning out a bed on the other side of our yard yesterday, in part to transplant a purple rhododendron that was growing into some yews, and I stopped to realize that up until last year we had a very old, large Norway Maple that was becoming diseased and was losing many limbs, and so we had it cut down. I had forgotten about it actually. But, all surrounding and indeed right next to this Norway Maple were planted many years ago various yews, arborvitae, boxwood, a few rhododendron, and a bit further away blue and Norway spruces. And these plants did very well under this large tree. The yews for instance grew quite big. Yes, some of the arborvitae maybe weren't as full as possible due to the shade, but for the most part everything took nicely. And everything planted is 15-20 years old.

Then, I thought of another area, where we lost again a Norway maple during Hurricane Sandy and similarly where we had planted a lot of shrubs and small trees. While this bed did not coexist with the maple as long as the first bed I've mentioned, only 5+ years, the plants within it seemed to do fine also. And almost everything planted was left-over, second nursery stock, so not always the healthiest plants to begin with.

Perhaps the plants did okay simply because they were individual Norway maples, rather than a woods of them, and so received light and water sufficiently. Or perhaps the more mature the tree, the less vigorous the roots (though I doubt this). The only other reason I can think of is in these areas we have always watered them quite regularly, in fact maybe too much. We've reduced our watering the last few years, but maybe that extra care and attention was what allowed these plants to establish themselves well, despite the invasive tree. And maybe once established, they can hold their own. Granted the rhodo I removed yesterday had started to sprout more vigorously this year, without the tree there, but I'd say it still wasn't bad all that time.

Whatever the reason the bed managed under the maple, I am a bit more hopeful in being able to deal with whatever trees have to stay.

Joe