What about something as simple as a grouping of three dwarf arbs? That way it is a bit more permanent yet achieves your immediate goal for the most part.

Technito is a nice and fairly readily available cultivar that you can probably get in a 5 gallon for $40.

http://blog.northerngardener.org/great-plants-for-northern-gardens-day-26-techny-and-technito-arborvitae/

Whatever you don't plant 2 of something inbetween there.

Thanks whaas,
Because of grading, anything shorter than 20' would not screen the neighbor's house. It would just screen the neighbor's lawn...

This post was edited by ttonk on Mon, Sep 9, 13 at 23:49

first off.. what kind of maples ....

second ... you are already over planted.. given decades ... for large trees i mean ...

your root issue.. is the yard grade.. and the fact that they appear to already be 4 to 8 feet taller than your soil back there ...

frankly... ANYTHING you put there... will be outgrown by the maples ... meaning they will grow together.. long before what you want to plant now will get to the height you need ... and it aint gunna take no 15 years .... [BTW.. i dont see a root flare on the left one ...know about those???]

so the issue is to choose things for your understory.. regardless of function in regard to that house ...

whats behind the camera??? .. is your house on the same kind of rise????

the solution might be to put things closer to your windows .... rather than focusing completely out at the property line .... and when in 5 or 10 years.. the maples are doing the job... then you remove things that fixed the problem faster ...

see link in regard to property line versus closer to your house.. though i have NO CLUE... whether that plant would work for you ....

ken

Here is a link that might be useful: link

Your understory plant wouldn't get removed as that will be the slower growing plant to fill in the space below the canopy of the larger growing shade trees.

I still belive an evergreen grouping to fill in the space inbetween and below the canopies of the maples is the way to go. We'd have to select something that matures around the 6-10' mark (and has partial shade tolerance) depending on far you limb up the maples which will likely be 6' based upon your screening needs and then mowing/head clearance.

Unless you're changing your strategy to simply have a permanent planting closer to your house I don't quite understand why you'd plant a plant with 20' tall potential when by the time it achvies what you need it do your maples would have already filled in.

Perhaps I'm completely missing the boat here.

@whaas

I understand what you mean. Guess that is my dilemma. My hubby has the exactly same opinion as yours. Heck, he also said he wanted arbovitae. And my answer has been "why do we want to screen the sloped lawn?" I thought I needed a non-conifer with fuller canopy on top. But at this point, I'm open to this conifer idea.
Let's just assume that planting close to the house is not really a feasible option nor my preference..

This post was edited by ttonk on Tue, Sep 10, 13 at 14:41

I now have the same question that Ken had.

What maples are you showing there?

My guess is one is a Freeman, in that case it would be up to 20' wide in 10 years. They grow very fast when young and juvenile.

Heck the 10' wide Celzam cultivar I planted 7 years ago is already 20' wide.

To be clear, the pic was for showing the view of the neighbor's house situation. Planted are A. Blaze on the left and Red maple (don't know which cultivar) on the right, about 14' apart .

A. Blaze will go elsewhere and be replaced with a Pacific Sunset maple (Shantung & Norway cross) and the distance between two maples "will" become 20'.
***I'll post a new pic with the new tree.

This post was edited by ttonk on Wed, Sep 11, 13 at 16:13

i meant ...

if you plant things closer to your house .;... for faster sight blocking...

those are the ones you remove.. as the ones at the property line mature ...

w/o a pic of your whole yard.. including the back of your house.. and the house behind.. its really hard to conceptualize the situation.. cant you go two neighbors down.. and ask if they would allow you to take a pic of your own property ???

there is a maple that is as thin as a pencil and as tall as you want.. but i dont have time to find the name ....

ken

Here is a link that might be useful: i think there might be ones with better cultivar names ....

Acer saccharum 'Newton Sentry'

conifer kingdom has been getting some great reviews in the conifer forum ...

ken

Here is a link that might be useful: link