I have several in ground large trees I have top worked in my yard.
I graft using mostly bark graft on a high branch. Then to
insure the graft grows I make the graft the highest bud on the tree.
Unless you do that your graft may never grow even if it took.
Downside to more than one variety on a tree is one will always
outgrow the others. With my way of doing it I have one variety on the bottom
and one on the top so vigor of variety is not so important.
BTW the picture with arrows, those grafts are only one year old and already
as big as before the graft. They grew around 8 feet in one year. Root stock is citrange.
I have gotten lots of scions from CCPP thru the Texas bud wood bureau in the past. Not so much
lately as Texas has started to charge a $150 handling fee on out of state budwood in addition to $40
per variety and $35 overnight shipping.
CCPP won't sell me bud wood directly. Last time I paid $250 for giant key lime
and red finger lime and none of the buds took(approximately 40 buds). Sometimes budwood doesn't work
even though it looks good. Usually 9 out of 10 work for me. Interestingly enough, two varieties of pummelo
hybrid scions in the same order, all the buds took.
For example on large in ground trees:
sugar belle on top of pixie
bream tarocco on top of valentine
shiranui on top of sour orange
cara cara on top of gold nugget
shiranui branch on tango
One tree has branches of shiranui, turkish sugar orange
and mostly sugar belle seedling.