Amazing fast & healthy growth you have there - Congrats
For the bonsai look ..... it will take a few years, but you will be there before you know it
To get started - you will notice, the main trunk has a "bottleneck" like shape ...from that bottleneck down is the
caudex -
from the bottleneck up is where you will want to make any pruning cuts ....
Where at this bottleneck you make the cut is up to you .... 1/8 to 2" above where the stem narrows down....or right at the point of the narrowing ..... either can produce interesting effects
This first cut, will encourage 1 to 5 new shoots to form just below the pruning cut ..and will heal over in 3-to-5 years -
Spindly stems can be corrected by cutting off the tip and forcing new growth further back down the stem ...or just cut the stem off where-ever you want further back from the tip ....
Try to keep the exposed cut surface area as dry as possible ...at least until it hardens over - as a precaution ...sprinkle with cinnamon or anti-fungal powder (rooting powder with fungicide)
Can lesson the elongation & spindly stems ..by cutting back on nutrients and fertilizers
Do not prune if you want flowers ...... a way around that is do selective stem pruning - or wait until after flowering
As the caudex grows - it will outgrow the pot (especially at the rate your plants grow) - and adeniums have no mercy for clay or plastic pots - they have no problem breaking clay pots or make round plastic pots oval ... when that happens its time to re-pot the plant
Re-pot -
layer about an inch of rocks (or pot shards) at bottom of pot - this will help drainage -
lift the adenium out of the old pot (if it didn't break it) and knock, brush, or wash off all the old media ....especially - that inch or so at caudex and below where the old soil line was .....
look over all the roots - cut off any that are off white, tan or black
set the bare - rooted adenium in the pot
now, here is where we break the Golden Rule of "planting at the same level in the pot" .....plant about an inch or so higher in the pot - this will expose more of the caudex - and show more of the roots (the bonsai effect)
To prevent pot breakage - and expose more of the caudex re-pot once every 1-2 years ...
Oh yeah ...leaves stretching upwards - are what you want to see .... they are getting plenty of water and light
And be prepared not to see any results .....as adeniums seem to take forever to respond to changes
