Hi Christopher: the uneven hedge on the other side was a pruning error that I willok be correcting this season. it needs to be level with the beds and not with the slope if that makes sense. There is no retaining wall on that side. I want to raise the hedge for 3 reasons: 1. to have it begin at the sane level as the walkway and be consistent with the opposite bed. 2. to provide a pocket planting soace for some tree roses and small edging perennials. 3. Speed/ quick hedging.

Are the tree roses and edging perennials going inside or outside of the new hedge? If inside, you can consider creating a new bed for that in the gravel path with the same stone edging as the other beds. If outside the new hedge, I can see why you might want a new retaining wall, but I don't think it is absolutely necessary. Having a level planting space is not going to speed up trimming the hedge. That is a function of eye coordination.

A bottom line though, is if you build a new retaining wall, stick with the same stone. Changing materials will look like a bad add on.

Thanks for the advice re sticking to the same materials. The other plant material is going inside. It’s really just to soften the stone and give some interest. I can leave out the tree roses but some low growing perennials would be good I think. The gravel walkways are aligned with the central axis walkways so I’d like to keep them the same width (see picture from the other axis — the original view is to the right of the central fountain). Re having the retaining wall to raise the planting, I just don’t want to lose 3-4 years while I wait for the height of the hedge to catch up to the other side.

First, I'll say the contractor who did the stone was a Master Mason - it is just exquisitely built. You may not be able to replicate it. The other thing I notice is that this arbor area is a more natural arrival point from your axis - there is a distinct visual separation caused by the retaining wall and what appears to be naturally edged landscaping beds going into this arbor (similar to the pergola axis being more naturally landscaped). And, the grade is sloped as might be the arbors themselves. So I would agree with no additional retaining wall, where naturally edged, less formal landscape beds up against the new hedge, which is itself against this retaining wall would fit the concept. I understand the waiting part, but it looks like another hedge row will only need to grow ~36" (at the tallest end) to match the height of the hedges within the formal garden.

Thanks for reviewing. Yes they did a fantastic job. I had created an identical rose green in my old house where I was the general contractor and had someone put down flagstone for the paths. I learnt the hard way that where slopes and retaining walls over a certain height are concerned, it’s better to use a pro. I’m actually creating new beds on the side behind and to the right of the retaining wall. There will be a rose allee with about 5 of those metal arbors so it will be more formal. Planting against the hedge also doesn’t allow any planting in front of the hedge. I should mention that I’m not young any longer so speed is important 😂. Can you elaborate on why you and Christopher are less favorable about the retaining wall? Thank you!

A beech hedge strikes me as too large for that arbor. I'd put climbers on it. Roses and clematis is a classic arbor combo. Wisteria (get American not Asian) works well, too.

You didn't specifically say, but I think you want the new retaining wall to be the same height as the existing one (to get the hedge base at the same level). If you do that, the existing one wants to become just more edging like around your pathways - but it is not the same width or material. Yes, splitting hairs, but IMO you have a very thought out garden with a very defined concept, done exceptionally, so the wall should not "just be added to allow a hastened hedge growth."

If you really want to add the same stone retaining wall, I would keep it lower than the existing one, which might raise grade a foot or so on the tall end. At that point I would look at turning the corner with it (on the pergola side) to create some sense of what it is doing to the entire raised formal area.

Let me ask this, will the covered arbor(-s that read as one large one?) require a hardscape under them because the grass will not sustain from filtered light? If there is a more formality of these arbor areas, from say a decomposed granite area under the arbors, then adding a lower retaining wall in a different material would work too. That material then would be a component of the "feel" of this particular axis area, used in other similar ways if possible.

Or you can probably find larger specimens of the same variety, for more money, to lessen the wait time and continue this axis area's naturally curved and edged concept.

Sigrid: the beech is not for the arbor but for an adjacent hedge. Climbing roses are goin on the arbor.

3onthetree: I like your point about turning the corner and also making it a bit lower if I do end up with a retaining wall. The allee path first best for me is pea gravel edged with cobblestone and with wide stepping stones across the pea gravel. This would link it with the pea gravel in the parterre but the stones would make for a more comfortable walk and bring a bit of interest. Budget being a consideration, I might just put horizontal stepping stones placed in t(e grass this year and then do the pea gravel next year. I only found one place with the 6 feet beech hedging and it just wasn’t affordable for me. At this point, I’m leaning towards not doing the retaining wall but building up the corner where it’s highest a wee bit with boulders and planting some frothy perennials to disguise that side…

I definitely agree with what has been said so far. No new retaining wall unless you are willing to terrace the entire lawn where the arbors are sitting.

At some point, there is a transition in the slope, and that is best done between the wall and the beech hedge.

Mad_gallica: Thanks. I think we have a consensus and I’ve saved some money for sure!

Thanks to all for the very useful input. I appreciate it very much. I will come back once the hedge is in to show the results.

I had promised to come back once the hedge was in. Better late than never. I ended up building up the original right hand side slightly and curving it around and using some large boulders to hold the soil. I realize while I took several pictures from the way we normally approach it (from the patio), I didn’t take pics from the other side, which is the side yard. We have snow piled up now so will post these for now. Once again thanks for all the input. I’m pretty happy with it.

Gravel will be topped off to better match the color.

Don't introduce another retaining wall detail. If you have to install a small section, match it with what's already there. If you introduce another detail like coreten, it would only make sense if you do it site-wide.

Thank you for commenting. In the end I used boulders from the same stone just around the corner and have some draping shrubs that “disguise” them.