I have a 30+ year old citrus, and when I acquired the house it sits next to, it had already been taken over by the rootstock, and now has 5 trunks (4-6 inches in diameter) that go up about ten feet. Much of the branching and foliage is up high. The fruit, although abundant, is sour and puffy, so there is nothing left of the original graft.

I've been trying to graft onto it but it's been difficult because the few low branches are small in diameter and are old wood. I'd like to figure out the best way to get it to create some new wood down low, but I don't really want to top off all five trunks. I have another old tree, Valencia orange, that after I started taking care of it(ie watering and fertilizing) has many young green shoots/branches just popping out of the 4-5 inch diameter lower branches/trunks. After one year, most of these new green shoots have blossoms and even fruit on them. But the first tree isn't doing this so I'm trying to figure out what to do with it.

Can I insert a t-bud right into a 6" diameter trunk, will that work? So far there's no sign of the bark slipping, and I don't know if it will on such a large trunk/branch. Should I top off one of the trunks, see if that will send a signal to the rest of the tree? Are there other kinds of grafts I could try into the larger trunks/branches. I'd like to hear some suggestions...this is still a healthy tree and I want to graft many different varieties onto it if I can figure out how to do it.

jc

I'd try the texas bark graft on 3-4 inch branches. No kind of graft works good on a 6 inch trunk. See the following link:

http://aggie-horticulture.tamu.edu/propagation/inlay/inlay.html

Here is what I did:

http://members.fortunecity.com/pjsauber/TopWorkingACitrus.htm

Here is a post Joe Real did about grafting on to a large older tree. I saw Joe in Jan and asked about the tree. He said it is doing very well.

link

Helix

You could try CHIP BUDDING. Use big budwood sticks and insert a few buds around each trunk, if you can access 360'. You will have to slightly vary the budding height of each bud, to tape them up individually. I wouldn't start to graft OR bud too low, in case you have to repeat the work. If you can work higher at less than 6"trunk diameter, there will be less stump surface to deal with.