AusBonsai

It's coming up to that time of the year I am going to start doing magor trunk chops and some branch reductions. I know that there are conflicting opinions on the benefits of using cut paste, some say that it is not needed while others say it is a must for successful healing of the wound.

From my limited experience it does prove useful, I have noticed that the preparation of the wound site plays a big part in the end result. I have read varying ideas on the best types of dressing from DIY to the imported Japanese specialty products. I have seen Yegbong advertised as a tree wound and grafting dressing. Has anyone any experience using this product and any opinion would be appreciated.

My understanding is that to be successful the product should keep out excess moisture while sealing the wound from insect and bacterial attack and stop the site from drying out.

I don't know if it's a must, but there's an old study suggesting faster wound healing when the would is wrapped in black plastic. I guess cut paste has the same effect. https://crataegus.com/wp-content/upload ... o-1978.pdf

Somewhere way back in the forum Grant Bowie posted a comment or started a topic that discussed using cut paste covered by cut putty once it had dried and the rapid closing of the wound he observed. I believe he had a similar untreated wound that barely had closed up to compare to.

One thing to keep in mind is that the cut putty and pastes sold for bonsai have some hormone in them that promote callus which is what closures over the wound. These tend to hasten the process. The common putty I see around comes in 2 different strengths. One for conifers or slow callusing species, and one for deciduous or species that callous easily. Before I knew this I used the putty I had on a Japanese Maple. It must have been the conifer putty as it produced a very large ugly callus rather quickly.

It has been suggested in general horticulture that sealing of wounds can also trap in moisture and bacteria causing more harm than good, and is no longer recommended practice. Instead cutting at the right place and correct angle is recommended. This doesn't always leave the most desirable result for Bonsai.

It is also worth noting that if you have a large wound, rewounding the edge and applying more paste/putty every 6 months or so can speed up the process.

I have seen suggestions that some brands of Bonsai cut paste have two types with different colours to match the bark colour, one for deciduous and the other for evergreen but essentially the same formula.

I would imagine that different climates in the same season would have vastly differing conditions. when I lived in South Aus the winter / spring times were wet and cold whereas now in South Qld. we have warm dry days. These conditions being so different would have less potential for moisture and bacteria to be problematical.

It would be interesting to hear what people have experienced in different climates to see how they treat cuts dependent on the area they live in, or apply or don't depending on traditional Bonsai methods.

I've had good experiences with putty on branches that have partially snapped from aggressive bending. I find the putty helps hold in some moisture while the branch heals over.

I have problems with larger pruning cuts when the cut takes a longer period of time to heal over. I get tiny white bugs that can get under the putty and although they are small and do tiny bits of damage, over a year they can put holes into the wood which go deeper into the tree. Somehow they can manage to get under the putty even when I kill a bunch of them, they soon come back. They don't appear when the cut is dry and exposed.

With larger wounds I get better results with just doing a better cut which can roll over easily and as Dansai suggested, every 6 months or so, I reopen the edges to promote new growth.

I think you also have to weigh up the species. Some species may be susceptible to rot, or bad scarring if you don't seal. Others may be more susceptible to insect damage with or without etc. Also, the local environment as suggested.

There's a picture in this thread https://www.ausbonsai.com.au/forum/view ... hilit=seal showing the results of 1 trial where I sealed half of a large wound on a JM.
While there are several alternative reasons that wound healed better on one side I also have other trials that have shown pretty convincing evidenec (to me) that sealing a wound does help with healing.
If you want to see more trials with wound sealer I devised a trial and posted results on Bonsai Nut - https://www.bonsainut.com/threads/cutti ... ost-654629 Keep reading through the first few pages to get to the trial and then results.

The trials you posted on Bonsai Nut seem pretty conclusive to me. The Japanese cut paste certainly proved to be the best way to heal the cut sites. I'll be buying some soon as I have some work to do on two Trident Maples I purchased from Shibui last year.