Beech lends itself to hedging since it has small leaves and takes clipping well. Planes have large leaves, even larger on new growth after pruning. I don't see a formal hedge being possible with plane but I imagine you could have a loose row of plane 'shrubs' if you regularly prune. It would be a slow job because you'd have to do each branch individually to avoid chopped leaves. Shearing wouldn't work.

Not really...but it does pollard well.

I see. Thank you for the answers.

My next question would be, since these are not basically coppiced trees, they will regrow as a multi stem from the base? I assume there will never be a natural form to these with 1 central trunk.

What kind of form can I expect? If these are multi stemmed, I may keep and just pollard to keep small / rounded because they have beautiful bark.

I see. Thank you for the answers. My next question is, since these are basically coppiced trees now… the stems coming from the cut leader will make a multi stem tree?

What kind of form can I expect? I may keep if multi stem and just prune / pollard eventually to manage height since bark tends to be beautiful when mature.

Sorry for reposting… my last comment had typos and no way to edit.

If you are regularly pruning you won't get the pretty bark. That doesn't appear until limbs/trunk are several years old.

To edit click the three dots bottom right. You'll get an edit option. If you're on a phone submit even if you're not finished and then open to edit. This site has a habit of losing everything you've written.

Thanks. I’m going to experiment and see what kind of trees I get out of this. If all else fails… chainsaw in 5 years.

@N K:

How about you tell us where you garden? That might make a large difference in advice provided.

Outside of having that knowledge...do you recall if your London Planetrees (Platanus x acerifolia aka Platanus x hispanica) were named selections, or simply seedlings? If they were originally named selections, you probably lost that quality with the dead original stem, and all the suckering stems are from the seedling understock.

NOTE NOTE NOTE: I would keep these in their pots for the rest of the growing season, and then plant them when fully dormant. You will want to wash all the potting soil off of them, and disentangling what will most likely be a bunch of circling/girdling roots - which would eventually kill off any attempt you made to grow these on to any kind of maturity.

You could recreate single stem trees from these outcasts, since they are very young plants and should have good stem attachment to the basal trunk. You will have some challenge in eliminating suckering for awhile, but as your new main stem grows the plant will direct its resources there for the most part.

If you intend to keep multistem character, I'll only chime in with the rest of the comments here. Northern European cities are full of pollarded London Planes, and maintaining them properly is a skill of public horticulture staff. Best have major reduction pruning done during dormancy, and then "haircuts" during the growing season to waylay any rampant stems/branches. These are usually produced along streets with narrow ways so that tall vehicles can pass, so views are not entirely blocked, and so that buildings are not swallowed. Many northern cities are also not very warm very often, so pollarded trees can provide modest shade when needed, but not create total chill shade all summer long.

Feel a bit cheeky to comment out of school when @floral_uk z.8/9 SW UKis afoot, but I think I'm hitting the target...

Pollarded...likely to keep adjacent sports court clear.

Immediately past those, unpollarded of same age...

Here are some pollarded Aesculus hippocastanum around a hotel/bar patio in Salzburg.

These are Exclamation variety. I’m in The United States zone 5b near the Great Lakes.

Feel free VV. None of those pix are from the UK.