Welcome to the NGA
First - find a desirable rootstock (the bottom portion) (for adenium, the caudex) ... usually, grafters use the caudex of Adenium arabicum for its unique ability to grow fast, unusually fat, gnarly and somewhat "squat".... (although any of Adenium species rootstock can be used)
the rootstock must be healthy and actively growing ...if it freezes at your location - adenium will go dormant for the winter (not actively growing) ...and grafting will need to wait until next spring
the grafted portion, or scion ...is the upper branch of a desirable plant that has interesting features - such as, exotic colors, flower structure (double or triple) ...or even interesting colored or variegated leaves -
the scion (or graft) must also be healthy and actively growing ...
leaving rootstock in the pot will make it easier ....
to begin - you will need a: very sharp knife - a nail - and grafting tape -
chose where the graft is to be - and - which branch you want as the graft ..
the graft shown in your picture is a "simple graft" .... where a smaller diameter branch is "joined" to a larger diameter branch
cut branch off rootstock -
use the nail to make a shallow hole in the larger branch (sliced portion of the rootstock) ....respective to the smaller scion diameter
use knife to "sharpen a point" on the smaller diameter branch - respective to the shallow hole
remove only enough outer skin (bark) on the scion sides for fit
check for fit ....there must be a tight fit - not loose - like a glove and without wobble
wrap your new graft with grafting tape ....some use Cyanoacrylate (superglue)
start grafting tape well below the graft on larger branch, wrapping upwards - making sure each "wrap" overlaps the layer below it by about half - so rain water will cascade down over the tape -
each wrap must be tight enough to keep water or rainfall from getting under tape
keep this portion dry ....
water only as needed -
fertilize a few weeks before starting -
and in a few weeks you will know if the graft "took" or failed - by observing the condition of the top most leaves, if dead or alive ....new leaves or flower buds are a good sign ..
as new leaves or buds form add another week to 10 days then carefully remove tape - unwinding from top down
grafts may be especially easy to break off in the first few years ....handle with care
the "step" you see in your picture (the difference between the diameters of the rootstock and scion) - will eventually "even out" or become not noticeable as time passes - (5 to 8 years ?)
do not expect anything anytime soon ...as adenium take forever to respond to changes
Stop in anytime over at the Forums > Adenium
https://garden.org/forums/view...
Good Luck
