Trying some cloning
perlite and starting mix 50/50%. IBA hormone too.The lowest branches are going to get air-layering treatment, potted and bagged with IBA rooting hormone. They will only be cut loose from their mother once roots show in the rooting media (50/50% perlite/starter mix). I will 'scar' the bark slighty and the rooting hormone should encourage robust rooting while they still have life support from the mother plant.
I'll document the process with photos in a detailed post. I've had great success with air-layering many hard to propagate plants. Kratom will be a first for me.
@peteypyro actually they need a pot upsize, so I can air layer the lowest 2 branches of each plant, UNDER a layer of damp rooting mix, IN THE NEWER BIG POTS THEMSELVES! Much easier than wrapping plastic around each branch. I might get 8 more clones from these 4. Anywhere a branch is scuffed up, and rooting hormone is applied, AND it's in damp rooting mix, it will grow roots. Makes cloning easier.