I vote to repot and cut all the stalks down to about 3 inches and let it grow a more attractive shape. The leggy shape it has now is from lack of light. With enough light it will form much more dense foliage.

Green-stem cuttings will root very easily! I'd start a new plant by taking one or more cuttings (several inches long with green stems) and put them in a glass of water until you see roots start to grow, then pot them up.

10 yrs. in the same mix? I'd start w/ fresh mix before anything else & that will also give you chance to assess the roots when repotting.

thanks for the replies!
I will report for sure, but I am reluctant to cut the whole plant down. I took some cuttings last year and they rooted nicely, but they seem to be growing very slowly. Maybe I need to give them more light.

I have ideas. I have ideas (raises his hand). Call on me before you operate, please!

Al

Hi Al!

I would love your help on this one as well!

As I noted above, I'm not too keen to cut it all back! I will add that it's been in a Northern window for a couple of years.  I can bring it outside for the summer and could maybe find it a better spot for next winter.

I have been reading lots about root pruning, and soils, as I definitely need to deal with reporting this first.

For root pruning, I gather from old posts on this subject that I need to remove bottom of the rootball (not looking forward to this), wash the roots to bare root, remove some large roots esp below the trunk, remove any "bad" roots.  

For the soil, I really don't know what to do.  Most of my plants have Promix Premium potting mix with added perlite. I won't be able to make a gritty mix at this time.  I could try a 5-1-1 but I haven't been able to find pine bark fines.  I've got repti-bark but that's not composted at all, and the pieces look a bit big.  I've got orchid bark but those are HUGE chunks.  I may still call around to some nurseries and see what I can find.  

Here's a pretty significant tangent:

I did make a 5-1-1 mix with the repti-bark but I had a very hard time figuring out when the soil was drying out, so I think I under watered my plant.  I actually only used it for a string of hearts, which likes to dry out, but I noticed it was struggling after some months.  The plant grew huge tubers but I realized there were almost no roots growing from the tubers into the soil.  This failure led me to quite mistrust the mix I made and makes me wary to use it again.  I will note that I did like how well draining it was.

Anyways, back to the scheflerra!

Here are some other pictures.  I've labelled the branches to hopefully make it more clear.  It looks like there are actually 2 plants.  Trunks A and C are the thickest.  Trunk B wraps around C.  Trunk C is the longest, and it had a very thick branch with tons of very healthy foliage (that's the part closest to the window).  Trunk D is the shortest.

One question... Are the not-straight branches typical of Schefflera?  Or is that something I inadvertently caused?  I do like it.

Thanks!

Elena

here's another photo, taken 90 deg turn from the other ones.

Lest I forget, let me tell you now that the images and highlights are very helpful, because it's difficult to fix in the mind the 3D spatial positioning of branches/stems from 2D images.

I realize you don't want to cut the tree back to stumps, but I'll make some suggestions as I go through the rest of what you offered, then you can decide if what I said makes good sense and is something you can be onboard with. Also, if I suggest something w/o a reason, don't feel bashful about asking what my reasoning is.

I have been reading lots about root pruning, and soils, as I definitely need to deal with reporting this first. I don't see why you can't repot and prune at the same time, but if you have reason to want to delay either part of the process, that's no problem either. I'd probably do the pruning first, then have everything ready for the repot so you can dive into that as soon as the plant starts to back-bud.

For root pruning, I gather from old posts on this subject that I need
to remove bottom of the rootball (not looking forward to this), wash
the roots to bare root, remove some large roots esp below the trunk,
remove any "bad" roots.

It might be helpful to read through THIS THREAD. It will give you a good sense of what the repotting looks like.

For the soil, I really don't know what to do. Most of my plants have
Promix Premium potting mix with added perlite. I won't be able to make a
gritty mix at this time. I could try a 5-1-1 but I haven't been able
to find pine bark fines. I've got repti-bark but that's not composted
at all, and the pieces look a bit big. I've got orchid bark but those
are HUGE chunks. I may still call around to some nurseries and see what
I can find. Do that. I just lucked into a pallet of PBFs that are perfect for 5:1:1 or gritty after screening, when I called a supplier I regularly use for bark and large bags (4 cu ft) of coarse perlite. There were 54 bags and I got them at half price because the plastic wrap securing the bags to the pallet was torn. I'll save what I need for soil and the rest I'll share or use as mulch. It was sold as Pine Bark Soil Conditioner. Try asking whoever you contract if they know where you might find the bark. I know it's not always easy to find, though I have never had difficulty obtaining it.

I did make a 5-1-1 mix with the repti-bark but I had a very hard time
figuring out when the soil was drying out, so I think I under watered
my plant. I actually only used it for a string of hearts, which likes
to dry out, but I noticed it was struggling after some months. The
plant grew huge tubers but I realized there were almost no roots growing
from the tubers into the soil. This failure led me to quite mistrust
the mix I made and makes me wary to use it again. I will note that I
did like how well draining it was. There seems to be 2 different sizes of Repti-Bark, both of which are too large to be ideal for the gritty mix, and I would expect the problem you described if using them to make a 5:1:1 mixture. Adding peat won't work well because the disparately large difference in particle size will force the mix to stratify. If you can find Turface or calcined DE that's stable, you could mix that into what you have remaining and come up with a workable medium. You could also stick with the ProMix with coarse perlite added and use ballast in the bottom of the pot to limit the amount of medium capable of holding perched water. Beyond the small effort it takes to set up use of ballast so it works properly, it's a passive method that works efficiently, even if not as efficiently as a medium that sort of self-limits how much excess water it can hold.

Here are some other pictures. I've labelled the branches to
hopefully make it more clear. It looks like there are actually 2
plants. Trunks A and C are the thickest. Trunk B wraps around C.
Trunk C is the longest, and it had a very thick branch with tons of very
healthy foliage (that's the part closest to the window). Trunk D is
the shortest. When you have a living plant, there is nothing in the way of rules that say you have to suffer looking at the parts that don't compliment the composition. When I looked at the first image you posted in the OP, I saw 2 interesting branches/trunks that compliment each other nicely, and quite a bit of unnecessary noise that detracts from what can potentially be done with those 2 branches. The branches that show conspicuous promise are A & C. D would definitely be removed entirely, and for now, I would truncate D immediately distal to D1. I don't think D1 will be used in the resultant composition, but it can always be removed at a later date. A wouldn't be pruned at all, and I would prune C back to somewhere along the arc currently serving as its apogee. From that point forward, there will be MANY opportunities to develop an eye-appealing planting with a unique form and tons of character.

One question... Are the not-straight branches typical of Schefflera?
Or is that something I inadvertently caused? I do like it. If the plant doesn't get a lot of light, the branches can become vine-like and therefore twisty. If a branch/trunk is truncated, the next order of branching can stick out at unsightly angles. For me, that's no problem because I have many ways to get a branch to grow toward where it best suits the composition, but to my way of thinking, the plant itself has never cared a whit about its appearance being called unkempt.

One of the things that will make a huge difference is getting it out into full sun and fertilizing it regularly.

This is a root-over-rock planting I started on a rock from my grandmother's rock garden:

Other pants in showroom of business before I sold it and retired last Sep:

Hi Al,
I try to make it as clear as possible to see what we're working with, so I'm glad that you find the branch highlights helpful.  

I was not clear about the repotting... I will root prune at the same time, probably in the next week or so.  Not sure if I need to pot up as well, what do you think?

For a start, I'll remove branch B and prune branch D where you said, then will share some photos again.  I expect most of the existing foliage will burn in full sun, since it's been in quite a low light condition.

Thanks so much!  Looking forward to give you some updates!

Elena

Ok wow... the repot was interesting. There were a few huge roots circling the container with not much in the middle. I made 3 or 4 cuts of these and the whole bottom of the root mass feel off. There were barely any fine roots in the top part of the container. I guess all the fine roots were in the bottom? So there are barely any fine roots now once I repotted. Hope this plant survives.

I did adjust the angle of the trunks in the new container, and pruned the top a bit more (I had already done most of the pruning cuts discussed previously with Al).