hey you planted large transpalnts.. 2 to 4 years to get established.. frankly yours look fine... look to the growth tips... they seem lush and green ... thoug perhaps you dint get A! stock.. they will fill in nicely ... you need to insure they are getting water into the root zone of the transplanted ball .... water as you will.. then gently dig a small hole near one of them.. and see if you are getting water down into the root zone .... if not.. water deeply.. and dont water again until they are nearly dry ... a nice 2 or 3 inches of mulch would also aid greatly in reducing water loss ... you can NOT guess as to whether you are getting water down into the root zone.. FIND OUT!!!! .. without doing too much damage .... mine .. planted at 4 inches.. are going on 15 feet.. 9 years later .. ON YELLOW SAND .... ergo.. your soil is not the issue.. the issue is how water moves thru your soil ... and how you INSURE that the conifer is getting what it needs.. as i said.. NO GUESSING ... ken ps: never ... ever .. do the plant spikes again.. waste of money.. and of no value.. IMHO ... unless a soil test shows that your soil is lacking something.. all these plants will need is water ...

Well now...It turns out I might have a little bit to offer here.

I love walls of emerald green arborvitae, especially their texture, color, and fullness/density. Here is a pic I took about an hour ago at Muirfield golf course(Memorial tournament). Love the wider spacing, this is gonna be a killer wall in 10+ years(road is to left of bike path, need to focus on putt). Looks like they disregarded the internet, which generally suggests 2’-3’ spacing for wall, when deciding on spacing(check out the dead one). If Jack Nicklaus approves Thuja Occidentalis Smaragd as a privacy screen, then they must be good lol. Id say 21, 5-6 footers for 850 is a good deal. Still small enough to “become one with the ground/established” rather quickly. Even the 10+ footer I planted 5 years ago did good, though the smaller the tree, the quicker they get established. I have seen tiny tots outgrow larger trees on more than one occasion. I didnt believe what people were telling me until I witnessed it. All the $5, 1.5-2 foot Smaragd I planted 4-5 years ago are gettin close to 5’, some might be more. In looking at the pic, and knowing that there are lots of deer here, (some of) these may be getting deer pruned, though just a bit. The right two perhaps.

I am removing these roots. Almost every resource says to just make sure to plant a few feet away, and many testimonies say their new tree is doing fine years later, but even 8ft away I am hitting like 3x3 fresh lumber I can make furniture with lol. Ultimately I think this is a unique scenario because I checked youtube vids like below and although some of those trunks are much smaller than the Silver Maple, the ratio of roots-to-trunk size seems way different as if this Silver Maple made clusters of much thicker and longer roots for its size - I think it's because the sandy/clay grading soil when they built the development makes things root shallow in this location. This is how a lot of developments are built, they use cheap sandy/clay stuff for the main grading and then only about 18" of good soil on top for the grass and trees, and also I've heard this whole side of town was basically a swap or something once upon a time, google maps even shows a blue line (river) along this fence line but there's never been a river, maybe an underground spring or something hence the map's river line starts and ends with no body of water and I've replaced fence posts here when it hasn't rained and basically hit an underground river (the wood underground was solid because no oxygen is why fence posts usually rot at the base only). I removed the stumps and roots of a row of blue point junipers that were chopped down like 7 years prior and they were still solid. If the roots look like the below vids, then yes go ahead and plant close and don't even worry about that little amount of roots in fact yes it'll just add organic matter I'd prefer to leave some roots if it's sandy/clay which is what I'm doing adding small roots back into the mix and mixing the sandy sub soil with the dark rich compost topsoil. Green giants are well-rooted and unlikley to tip over from windthrow, and they might root deeper into the sandy/clay stuff just below the old maple roots, but bottom line is there's too much big roots in the way that I know it'll be better without them, I can't even dig a 1ft wide hole for a new tree without hitting something decent. Some trees cost too much to risk it IMHO at least get some of the old roots out, setting up irrigation, transporting the trees, fertilizing etc better to not risk it if the conditions and old roots are like this. Another thing is if a previous tree/roots had disease, it could enter the new tree, but as long as there's not a ton of old root mass, then maybe it's not a big deal and the soil microbes will correct it, but just wanted to note that about planting near an old stump. And well, you can't just make quick work of roots with a chainsaw because it'll dull in 5 seconds and you'll spend more time sharpening than cutting (although I might sacrifice a chain for this and test my dremel chainsaw bits for once because usually I just hand file), but it's not too too bad removing roots. It rained hard and turned my project into a pool that I bucket'd mostly out and then filled the finished areas back with soil and it was like working on quicksand but it's getting there and the farther away from the stump the easier it becomes. Sawsall pruning blades dull really fast too and I resharpen them on a bench grinder but it's still takes a while. I've been picking at them with an axe, splitting wedges etc, rain-soaked compost topsoil makes it a lot heavier and everything slippery, been going at it with a jack hammer with a sharpened chisel bit does decently. This Silver Maple stump was like 3ft wide at the base. I just removed a different maple's stump and roots from the sidewalk grass strip area to plant new sweetbay magnolia and that was about a 1ft maple stump but the ratio of those roots to the large silver maple doesn't correlate, I was able to rather easily remove the whole stump and what seems like the only main roots it put out due to being confined between the sidewalk and street compared to the large Silver Maple really put tons of big roots out. sorry so long, Another things though is Green Giants are an extremely QUICK growing tree so I would still prefer not to have even medium sized roots near them. Tree services should offer the option to grind the roots too if they're this big. The Silver maple roots I'm removing are much bigger for the trunk-to-roots ratio than these trees it seems likely because of the site conditions https://youtu.be/N3RUifC7Uo8?t=310 https://youtu.be/Fjg7ieBY7Lk?t=434 https://youtu.be/bRTIwWUg4fc?t=152 https://youtu.be/vM24klVyxFk?t=477