Yes: there is a reason why part of the name is "Giant". Anyway they will soon reach the fence but because it is solid they won't grow through it. So the only problem will be if anyone ever wants to work on your side of the fence they won't be able to get at it.

And of course the trees will grow over onto the neighbor's side above the fence level. As for the spacing between the trees it will assure that you get a solid screen fairly soon but shouldn't be a problem for the trees. Even then it is of course going to take many years for them to produce the effect you want right now. So you will probably have to do something additional to get the enhanced privacy you desire. If there is an outdoor sitting area involved maybe put up something over where that is, instead of over where the neighbor is. With the latter response - although frequently demonstrated by others also - being the least efficient way to eliminate an unwanted view.

Since you've had them a short time, can you return and exchange them for a smaller variety?

The bed is about half the depth it needs to be even for a smaller variety. Since you have a bed, it would look good if you planted groundcover to grow solid around all the trees.

The obvious replacement choice is Thuja occidentalis 'Smaragd' but that will not shoot up quickly like the 'Green Giant'. So the wait for the desired level of screening would be even longer. But that is almost always how it is with hedges and screens. That is the tight and tidy kinds are slow, the fast ones bigger and looser.

@Yardvaark, so are you saying we should make the bed 10' and move the trees to be 5' from the fence? Or more? We can move them to the front of the existing bed and that will be about 5' from the fence. Or we can pay to have the bed extended again.

@Embothrium yes we picked Green Giant because we wanted something fast growing. I just thought they were narrower than they really are! I also heard they are more hardy. We were looking at Emerald/Smaragd but those only get to max 15' and we were afraid they wouldn't get tall enough since our yard is raised. We did build a patio with a pergola on the side of our house for that reason which we love. We still would like to use the rest of our yard with privacy because they are out there every day.

I going to remain skeptical about the claimed depth of the bed as it doesn't look close to the height of the fence. Nor do the plants look 2 1/2' away from the fence. A 5' depth bed would work for a while for a smaller variety of arb.

There is no reason to think 'Smaragd' only grows 15' tall. And there is existing evidence that it grows taller. Anyway no still live, healthy conifer grows to a specific height and then stops growing.

@Yardvaark, I agree it doesn't look that size in the photos but I just went outside with a measuring tape again and I can assure you that from the front of the edging to the fence is 5' and the center of the trees are a little more than 2.5' from the fence.

We are stuck with these trees but we can move them further from the fence. I know nothing about trees so I'm just trying to figure out what would be a good distance to plant them from the fence. If we move them 5' out is that enough for the long term or if not how much? I'm fine with having the edging redone but I want to make sure we give them enough room, but I also don't want to put them in the middle of the lawn or I guess we will just have to get rid of them.

The minimum would be 5 feet from the fence and 8 feet would be ideal. They do want to be 10-16 feet wide...eventually.

tj

"They do want to be 10-16 feet wide...eventually."

They can get a whole lot wider than that!! 20' is typical and I've seen a few even wider than that.

Is it possible to prune them to keep them narrower at the bottom? I was reading you can snip the top leader at the height you want to stunt the growth. Can something similar be done for width?

How long on average does it take to get that wide? They are 3' now. Trying to figure out if I'll be dead by then :).

Where are you located?

tj

I would bite the bullet, leave them where they are and just keep them trimmed. You can't let them overgrow and then swoop in later and save them. You have to be trimming them right along, always working with their green foliage, not with the stems that are underneath. Mainly you'd be trimming backs and fronts while letting the sides grow together to form a hedge. You have to MAKE them fit the space. Research the correct profiles for shrubs. You'll want to trim them so they'll maintain their bottom foliage.

@tsugajunkie z5 SE WI ♱ we are in the suburbs of Chicago, zone 5.

This may be sacrilege, but I had a neighbor who tree formed a row of green giants on her property line. The original homeowner had planted them on top of the water access and she had to get to the shut offs for the house and sprinkler system. She had the limbs removed up to about 5 or 6 feet. It ended up creating a nice shade bed for her. Last I saw they were still doing well.

Julee- Call the Morton Arboretum and ask if they have any mature GGs. If so, take a field trip and you’ll see how they grow by you.

tj

Good idea @tsugajunkie z5 SE WI ♱! They have an online database and looks like they have quite a few. Now I just need them to open to the general public since it is members only right now because of Covid-19.

So I finally heard back from the company I ordered the trees from when I asked about what to do and why their site says the trees only get 8 feet wide. This is what they said. Is this possible or is this a load of bs?

"Moving them to the front of the bed will work well. Because our variety gets only gets up to 8 ft wide, while others are wider, our trees will only need to be 4 ft away from the property line or fence. "

LOL!! A 'Green Giant' is a Green Giant. They don't come in a range of mature sizes. You can expect a base width of 15-20 feet in time, possibly wider.

So yes, I'd consider that a load of BS :-)

The key point is if they are calling them 'Green Giant' - and that is really what they are - or if they are actually supplying something else. Including a possible 'Green Giant' sport, that resembles the parent generally but also has some differences such as a closer habit. As in this example, where a branch sport of 'Techny' found in a nursery row became the basis for a more compact version of that plant:

https://shop.baileynurseries.com/Product/Detail/2229?availabilityDate=2020-06-14&returnUrl=%2FProduct%2FInventory%3Ffilter%3D%26category%3D30-EVERGRN%26page%3D3%26displayFilters%3DFalse%26brand%3D%26height%3D%26heightUnit%3DInches%26zone%3D%26exposure%3D%26pageSize%3D20

Or they got their first plants from cuttings taken off of a found planting of what was in fact another variety - this kind for instance:

https://www.provenwinners.com/plants/thuja/spring-grove-western-arborvitae-thuja-plicata

And thought at the time this planting consisted of 'Green Giant'. Then noticed later their material grew differently but are continuing to relate their plants to 'Green Giant'. Either occurrence could explain their reference to "our variety".

Also with clonal conifers positions on stock plants where cuttings originate can affect how resulting specimens grow, maybe they are using mostly small side shoots and this is happening to result in "our variety" being less robust than typical.

The Thuja Green Giant needs space to grow, 5 to 8 feet to create a nice fast growing natural privacy screen. These beauties can grow 3 to 5 ft every season so planning ahead for that is the smart thing to do. If you leave then where they are, they will definitely start pushing on that fence once mature and big enough, not to mention the roots growing towards the fence that may also create an issue. For a more slim tall species you may want to consider the Italian Cypress which is a more columnar style tree for that type of space. Columnar style is more than likely the type of tree you need in that space to avoid that fence. Hope this helps!

Italian cypress is not suitable for USDA Zone 5 Illinois.

Move them to the front of the bed and you'll be fine.

We are planting Thuja Green Giants this weekend on our property for the same reason - wanting privacy from our neighbors who have a pool deck. The nursery that we purchased them from told us to space them 7 feet apart. They are supposed to get pretty wide - 15-20' - and tall - 50'. Good luck with yours.

What did you end up doing? I am trying to decide how close to my privacy fence I can plant mine. I was planning on shaping them to a hedge about five feet wide and 12 feet tall before I realized I wouldnt be able to trim the side along the fence...