u/FamiliarAddendum7611

My strelitzias have been growing really slow and recently the biggest of the four was growing a huge leaf that snapped because of a weak stem.
I was suggested to change soil, since this one might be not draining enough causing cell damage. Today i decided to check the soil, that i have watered three or four weeks ago, and it still feels damp. I am now worried to harm the plant trying to get rid of the old soil, but i was also asking myself if it might be time for a bigger pot too. I also noticed there are small black roots and some bigger ones that are partially black

About light, they sit under a Sansi 36W grow light 12-14 hours a day. I usually bottom water, but haven’t fertilized in the past 3 months or so.

First 3 pics of the soil are from the right plant, last 3 pics are from the left plant.

Any suggestion about soil composition would be really appreciated. (I have bark, perlite, coco chips, horticultural charcoal, sand, vermiculite and vermicompost)

My strelitzias have been growing really slow and recently the biggest of the four was growing a huge leaf that snapped because of a weak stem.
I was suggested to change soil, since this one might be not draining enough causing cell damage. Today i decided to check the soil, that i have watered three or four weeks ago, and it still feels damp. I am now worried to harm the plant trying to get rid of the old soil, but i was also asking myself if it might be time for a bigger pot too. I also noticed there are small black roots and some bigger ones that are partially black

About light, they sit under a Sansi 36W grow light 12-14 hours a day. I usually bottom water, but haven’t fertilized in the past 3 months or so.

First 3 pics of the soil are from the right plant, last 3 pics are from the left plant.

Any suggestion about soil composition would be really appreciated. (I have bark, perlite, coco chips, horticultural charcoal, sand, vermiculite and vermicompost)

My strelitzia was growing a new leaf, the biggest one so far, and its stem started bending in the past two days. I tried to give it some support while looking for advice, but yesterday night it completely snapped off. The stem looked very weak and soft, with a very light colour. The plant sits under a SANSI 36w grow light for about 12-14 hours a day and I bottom water it every time the top soil is dry. This plant was doing great, so i was thinking that the only thing I changed was fertilizing. I stopped a couple of months ago cause i thought i was fertilizing too much.
Hoping that the next leaf grows healthy, do you know what happened to this one?

Also, this plant is currently planted with one other BOP in the same pot, and i have two more in another. Expect for the one with the snapped leaf, they have been growing reaaaally slow. Any advice?

(Last pic is from yesterday)