Maples are not known for strong allelopathy. But they can cast a lot of shade and have an extensive surface oriented root system. That combination results in a dry shade situation that a great many plants find difficult to adapt to. Whatever you select to plant in this area should be very tolerant of these conditions AND will still need routine watering to become established.

What older trees are dying, canishel? That might be an important clue. I would want to identify the cause as much as I could, if I wanted to have confidence in my plantings.

indianagardengirl,

Predominantly hickories and oaks. I try to remove the maples because they're so prolific. Some deaths were because of insect borers (other trees were since treated). Don't know about the other deaths.

What's so odd is the lack of any eastern red cedars in that area.

Are there deer?

Yes and no. The dogs chase away the deer. No evidence of more foraging than on the other sections.

Are you talking about Norway maples? Hard to get anything to grow under those.

Not Norway. Red and maybe silver.

Around here, red cedar is a lime indicator. If I drive 15 miles south on the main state highway, the pH drops from about 7.2 to about 5.2. About halfway down, the evergreens that pop up in abandoned fields change from red cedar to white pine. Soil & Water told me to look for that.

Oaks and hickories should be much more drought resistant than maples.

Can you add a photo of the area in question? Just post it as a follow up comment.

As Ken said we have no idea where you want to plant with regard to the maples. If you think an evergreen hedge will grow densely in deep woods, most won’t IME, but you may get adequate results from some of the shade tolerant broad leafed evergreens such as Kalmia latifolia aka mountain laurel or some of the more shade tolerant rhododendrons. But plant density will be much less than in bright shade or part shade, so it may not provide the look you want. And that assumes that you are able to plant far enough from the maples that the shrubs have adequate moisture. In general rhododendrons like evenly moist but well-drained soil and won’t be happy if it gets too dry IME.

Thanks to you all.

I thought there might be a simple answer, but I guess not.

I think I'll transplant a seedling eastern red cedar, and a small holly in the problem area this spring. See how they do, and evaluate in the fall.

Yes: any evergreen shrubs planted in deep shade will develop a thin, see through habit. But your original description doesn't really provide the kind of information needed to result in any responses beyond the general statements - including the one I made at the start of this paragraph - that you have gotten so far.

I haven't posted a photo because the slopes of "terrain" vary, so photos are difficult for me.

There are about 300 linear feet to plant. The cost of rhodies and mountain laurel is prohibitive.

Thus, my intent to transplant eastern red cedars (free, from elsewhere in the property) in a jagged line some feet from the property line. I may also plant greenbrier to grow up some hardwoods (very maybe); it grew well until I got rid of it... Arborvitae is growing nicely, but slowly midst the hardwoods, just don't have enough of them. I suppose they get enough sunlight in late fall through early spring.

Anyway, thanks again to all of you. I only expected generalities. You've given me a lot of thoughts.

I was also going to suggest Rhododendrons or Azaleas, but I'm a little late for that. But you think they're too expensive so I have this suggestion, buy small seedlings from musserForests.com. The Rhododendron Maximum is $2.05 ea for quantities of 25 or more. They also have a 10 quantity for $5.50 ea. I gave you the 25 quantity first because it's cheaper to buy 25 than 10!!! They also have the hybrids and they also have Azaleas at similar prices. 3 of 4 varieties are sold out!

If that's to cost prohibitive there's also seeds from:

https://treeshrubseeds.com/specieslist?id=469&ID2=-1&g=r

They have a variety of Rho's. The one in the link is $5.40 per .06 Oz. They have other Rho's at

https://treeshrubseeds.com/specieslist?id=527&ID2=-1&g=r

or

https://treeshrubseeds.com/specieslist?id=527&ID2=-1&g=r

Azaleas are at: https://treeshrubseeds.com/searchresults?k=azalea&match_type=0

Whether you buy seedlings or seeds I suggest you grow them in a nursery bed, from my experience the deer will eat them in the winter. You could start out with 2 foot chicken wire two feet apart and then put another length across the top. I see laurel growing along the PA Turnpike in fairly thick woods and it looks wonderful.

Wow! Thanks for the info. I can grow them next to the house in pots.

If the suggested source above doesn’t work out, I can often get quart sized Rhodies for something like $5 each at big box stores in spring. More expensive, but less wait time. BTW, Rhododendron maximum is one of the Rhodies that is fairly shade tolerant and can reach well over your head in size.