When you were removing soil and cutting roots, how long were the roots out of soil?

i use a 5:1:1 mix for all of my Ficus. 5 parts pine bark fines, 1 part peat, 1 part perlite. A fast draining mix works well for them.

How much light does the tree get?

i would have definitely have waited until around summer solstice to do this kind of root work.

if it’s not draining at all, make sure the drain hole isn’t plugged and I’d recommend using 50% perlite with your potting mix.

What a lovely tree & it looks like it has the health & vigor to recover well. It makes sense that if the disturbance caused leaf loss, then moisture usage would decrease dramatically.

This is an excellent opportunity to fine-tune its' wonderful shape while leaves are not blocking the view of the branches. Remove any branches going in the wrong direction, crossing, and then those in conflict with the shape you desire.

As you probably know, white latex sap will leak from any cuts, so you may want to wear gloves, an old shirt with long sleeves, and lay some newspaper around the floor if necessary to do inside.

Thanks Dave for your recommendations!

Roots were out of soil for 2 days. However I proped the tree in a way that the roots were sitting in a pot of water.
My flat is one big open space with 4 windows, so there is a lot of indirect light throughout the day.

Tiffany, Thanks for the kind words.
I will do some pruning as you suggested. :)

The pleasure was all mine. :) One thing I've learned about pruning for symmetry is to keep going around & around, don't stay on any side for long.

normally when you take out so much root mass you need to prune the leaf mass too - there's just not enough roots now to support the crown, so it dropped a lot of leaves.

Thanks Petrushka!

It sounds reasonable to only prune a little at a time, starting with the obvious dead branches. I will do so.

Moisting I already took care of. I cook a lot, so humidity levels are around 50% constantly.

As for the absorbing/draining qualities of perlite I am more confused, than before... :)

I understand it has a highly porous structure, therefore I would assume that it retains water, instead of draining it. So I am still worried that the perlite particels are holding too much water and therefore causing the roots to rot.

The following text is from an article on perlite. I also inculded link to full article.

"Physical Characteristics – Expanded perlite is very light with a particle and BD of 0.9 and 0.1 g cm−3, respectively. It is very porous, has a strong capillary action and can hold 3–4 times its weight in water."

https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/perlite

quote:

The available and non-available water in commercial perlite of 0–4 mm diameter was 13.6 and 36.5 per cent of its volume, respectively .

it slurps the water instantly but it holds on to it (has to do with surface tension), the water is not released into the surrounding soil to make it soggy.

foremost it aerates the soil (true whether it's small or large size perlite) so it helps to prevent root rot by providing more oxygen to the roots, not the other way around.

lava rock can be substituted instead - it'll hold water internally slowly releasing it to the mix. it's sort of like the sponge, sucks up extra water from medium and then slowly feeds it back. and it has nutrients too and is much larger.

if you can find it - use that to 1/3 of the mix. but perlite is easier to get and cheaper too.

https://sohumsoils.com/ingredients/perlite/

https://www.bettervegetablegardening.com/perlite-in-potting-soil.html

http://homeguides.sfgate.com/recommended-ratio-peat-moss-perlite-46321.html

oh, by the way 50% humidity is barely enough to keep it happy while it's in good health. but when it'd dropping its leaves we need to raise it to 90-100% to coddle it terrarium style. i remember a thread a few years back i commented on about this with pics after it stabilized in a tent. go look.

Thanks all for the comments. If you are interested I posted some additional photos on this discussion:

https://www.gardenweb.com/discussions/5305867/ficus-benjamina-dead-or-alive

btw, there are some misconceptions about pruning and transplanting that need to be cleared up. Removing top growth by pruning or reducing the foliage mass does NOT help with root development or regeneration.........in fact it does quite the opposite. It is the leaf canopy/foliage mass that supports and feeds the root system. When you remove that at the same time you transplant and damage/cut back the roots, you will slow root regeneration. The tree needs all of that top growth to photosynthesize successfully and provide energy to the root system. You can of course remove (and should) any deadwood but leave any additional pruning until after the tree has stabilized from its transplanting.

The Myth of Top Pruning Transplanted Material

Yes, I agree and learned it the hard way... :(

The article is about "landscape conditions."

It doesn't make one whit of difference if growing in the ground or in a container!! The principle is exactly the same. It is the same practice followed by all bonsai practitioners and container gardeners. The leaves/foliage is what promotes growth and root development. Cut back hard on the foliage and you will limit or even prohibit root development or regeneration.

Not entirely correct. If a plant is in good health with good root system then taking away half of the roots will not affect the top significantly. But in this case, I would definitely have defoliated the plant by 50% AND provided a humidity tent. There is just not enough roots to support the water needs of the plant. If you do not defoliate, the plant will do it for you as was noticed by the OP. Ficus are generally strong but this was a weak plant. The correct way would have been to cut some big roots and up-pot in a bigger pot and let it grow outside and become healthy. Late June or July it would have recovered its strength and would have been better able to handle the stress.

The article makes the distinction in the very first paragraph:

"Gardeners are often advised to prune back the crown of transplanted trees and shrubs by as much as 50% to reduce transpiration and compensate for lost root systems. Internet web sites, even the usually reliable ".edu" sites, continue to spread this myth. This is a common practice in nurseries where top-pruning of containerized plants reduces shipping costs and has been shown to increase tree survival and growth under nursery conditions. Research performed under landscape conditions, however, shows that pruning when transplanting is not necessarily beneficial, and may even harm the tree."