hi ralph ....

i dont think anyone here is going to be excited with your reliance on the leylands ... the upside of fast.. simply has too many negatives ...

but you could use some.. but dont plant them altogether ... no use spending 10 years to grow a screen.. only to have the whole die.. whereas between the thuja.. if one thing dies.. the others remain ...

i would hope you could find something outside of the leyland family.. but also outside the thuja.. since you have a lot of those.. though they are rather bulletproof ... maybe another cyrpto or two ...

the norway spruce is a telephone pole tree ... it will be a monster in a couple decades .... i would NOT plant one.. without at least an acre or two .... perhaps you wont be around to worry about it in 20 years.. whatever ...

on this one: Cupressus nootkatensis .. look for the pendula ...

and finally.. you said: I currently have a few eastern red cedars near 50' and would prefer that most trees don't tip out that high for posterity.

==>> as you are noting.. conifers are trees... and they really NEVER stop growing ... its all about annual growth.. and how fast they grow skywards.. per year ... nothing magically stops growing at some given height ... so something that grow 3 feet per year.. will be 30 feet in 10 years ... where as one foot per year.. 10 feet ... with screening.. its maddening.. because you want it screened yesterday .... but you dont want it 100 feet tomorrow.. what a wicked game we play ...

see link for tutorial on growth rates.. and more ...

good luck

ken

Here is a link that might be useful: also look for the link for coniferbase ... and figure out how that works.. to MAYBE get info on various cultivar names ....