Here is another picture. And btw, it's actually a 'schflerra amate soleil' which is basically a schflerra amate but with chartreuse coloured growth.

.... an attractive plant.

Root congestion has several primary effects on plants. It makes leaves smaller and internodes shorter, reduces o/a growth and vitality, and forces foliage to be increasingly persistent nearer and nearer to apices (areas where the plant extends in length). Shedding of interior/older leaves is often see as a symptom, which is just another way of saying growth is concentrated near apices.

At the same time, a notable increase in photoexposure can also reduce leaf size and shorten internodes, but that usually isn't accompanied by shedding of old/interior foliage. Even though these conditions impact schefflera in the same way they impact other plants, because of its growth habit it isn't always as obvious in scheffs as it might be in other woody houseplants.

Schefflera will definitely take full sun, but they might rebel at being in full sun where there is no air movement to cool the foliage. Unless you overexpose the plant before it's acclimated to full sun, it's doubtful that sunburn could (technically) be a problem, but overheating of the foliage and the dessication that accompanies it very well could. Your plants will take a lot more sun if you have a fan moving air and upsetting what is called the boundary layer (of air surrounding leaves).

Al

usually the more light - the denser the growth: less distance between leaves. the top new leaves are quite large, so which ones are smaller? the ones that just open up are normally very small and then they increase as they grow. it looks very good and healthy to me.
I don't see the curl, is it that the leaves are folding slightly? that could be due to drying up/ low humidity.
it is normally a fast grower: so new leaves pop before prev ones are fully grown.
I did a quick google and soleil prefers 50-63% shade - that is more shade then reg shefflera.
also it's very prone to mites when hot and dry in south/west windows - so be on the look-out or move it a few feet away from the window.

Al,

About a month ago I had pulled the plant out of it's container and checked the root system. It did not look root bound at all. Infact, some of the soil near the bottom stuck to the bottom because there were no roots to hold it.

As far as foliage drop, there has been very little since I have got the plant. The foliage that is missing near the bottom was pruned likely by the nursery.

Maybe it's just the sun then? In any event as luck might have it this plant is right next to a window that can slide open allowing for fresh air. I try to open the window everyday acclimate this plant to the outdoors as it'll be going on the balcony when temperatures are high enough.

So they can take fun sun then? This is good because the schflerra will be on the balcony facing SW in full sun, but of course the plant will need to be slowly introduced to these conditions. Wind is also a big thing as I'm 10 floors up and it can be full force as nothing obstructs it.

Lots to think about!

petrushka,

The third leaf from the top is the biggest. The second leaf from the top is second biggest, and top leaf is just opening.

I posted a picture of the curling below. The pennies are to give you a better idea of the angle. The humidity is around 40% last time I checked but I'll check again. The leaves do not appear to be drying up. It is the healthy leaves that are curling.

Hmmmm, well, for now I'll keep it next to the window and when the sun becomes more powerful I'll keep a very close eye for damage and mites. The amate, though not mite proof is supposed to be quite resistant to them but still, I'll be checking a little more often when it gets more sunny then.

Your plant looks very healthy and nice. I think the curling you are referring to is the natural shape of mature scheff leaves. Scheffleras are very adaptable and non-finicky, one reason they are so popular in the commercial interior plant industry, so humidity, or lack thereof, should not be a big problem. You might want to do a little more research on your 'soleil' variety, as Petrushka noted, if it generally likes more shade than the standard amate.