Posts tagged “thread graft

Grafting Hinoki on Thuja: Round 3

In Spring 2012, I tried bud grafting hinoki foliage on a scraggly collected Thuja, which failed. Later that year, I tried approach grafting hinoki foliage onto the same plant. Over one year later, the results are still unclear. The approach graft is alive and well, but it has not clearly fused with the Thuja tissue. I have a feeling the wounds on scion/stock both just healed over instead of grafting with one another. At this point I would say the approach graft was not successful.

Not convinced that this approach graft has taken.

Not convinced that this approach graft has taken.

Nevertheless, I left the approach graft in place and moved on with my third attempt of grafting this plant with a third type of graft: the One-Point aka Single-Point Graft.

One-point grafts are very similar to thread grafts, except defoliation is not required. This makes this type of graft a very useful tool for conifers. Many years ago, I successfully one-point grafted my Canadian Hemlock (Tsuga canadensis) after learning about this type of graft from Nick Lenz’s Bonsai from the Wild 2nd Ed. In fact, Nick hints at one-point grafts as being appropriate for Hinoki-Thuja operations, but first describes them in his larch chapter:

A variant of [thread grafting] is the one point graft. Instead of passing a bald branch through a hole in the trunk, you fold over a branch and squeeze it into the hole. Before insertion, you scrape the outer edge of the fold with a thumb nail to remove the cambium. When jammed into the hole, the cambium layers of the drill-out and of the scraping will touch and merge quickly. This approach has several advantages. You can perform it at any time during the growing season as the branch does not need to be bald. This is especially useful in species that grow out but once in a season, such as pines. It also takes less time to complete. You do not have to drill all the way through the trunk, but only a centimeter or less.

The disadvantage to this approach is not great. The branch may be fatally injured when folded over. If this happens and the new graft begins to dry and brown up, you can readily pull it out and try again with a smaller branch. Despite the tendency of a branch to break (crack) when doubled over, you can always find one that will tolerate the procedure. Success is more likely on hot, dry days when water is withdrawn from the wood. -Bonsai from the Wild 2nd Ed., p. 33

A few weeks ago in mid August I looked disgustingly at my still-ungrafted Thuja and grabbed my drill. Three one-point grafts were initiated and today they all still seem to be alive. Basically what I have now are three thread grafts in my Thuja, and hopefully now it is just a waiting game.

A one-point graft that seems to have survived the initial folding-and-cramming.

A one-point graft that seems to have survived the initial folding-and-cramming. The scion for this graft was growing off the scion used for last year’s approach graft.

Another one closer to the base of the trunk.

Another one closer to the base of the trunk. All of the one points were slathered with some Japanese wound sealant which is pretty much white glue.

I'm not sure if this tree is even worth all the trouble. Sure, it will be nice if I can make it a bonsai, but this grafting project now seems more about me proving to myself that it can be done.

I’m not sure if this tree is even worth all the trouble. Sure, it will be nice if I can make it a bonsai, but this grafting project now seems more about me proving to myself that it can actually be done.

 


Korean Hornbeam Cutting

I’ve been developing this carpinus from a neglected stump for about 6 years. Most of the primary branches had died back under the previous owner. I have been trying to build a new tree from thread grafts. It is coming along, but slowly.

Korean Hornbeam need to be cut back later than maples, otherwise they won’t backbud well. Usually this mean late spring, once the new growth has hardened off. This is also a good time to send through some thread grafts as defoliated branches will bounce back quickly, and smaller holes can be drilled since winter buds have not yet formed.Thread grafts can also be sent through in the late winter, but larger holes need to be drilled to get the branches through without rubbing off the large winter buds.

Healthy spring growth. I was planning on repotting this year, but never got around to it.

Leaves have just hardened off in the last week.

After cutting back. The tree will be moved to a sunnier location and fertilized heavily to encourage backbudding.

This branch was thread grafted a few years ago.

This is the first branch I threadgrafted on this tree. Funny that it is now supplying the whip for this year’s thread graft (note small branch wired inward)! Ahh… the circle of life… :)

This years little threadgraft, growing well. Note the size of the hole. This is the disadvantage to sending threadgrafts through in the winter. Larger hole = longer time period before the scion is large enough to start fusing with the trunk.

Some fruiting structures (catkins?) were spotted and removed. The branches that these grown on weaken dramatically. I try to remove the conspicuous flowers in the spring, but usually miss a few.