Club News – March 2020
On recommendation of local Public Health Departments
Due to the ongoing COVID-19 situation, the Board Of Directors and Officers of the club have made the decision to cancel our monthly meeting that was to be held on March 20th. We will resume our meetings as soon as it is clear that the risk of spreading the virus is over. When that may be, no one knows, but we hope it is sooner rather than later both for ourselves and the entire community.
60th Annual Show Cancelled
We’re also sorry to announce that our 60th Annual Show has been canceled.
The safety of our members and the public is far more important. We’ll be back next year!
Each month there are a number of tasks you need to do to your bonsai – from repotting, to fertilizing to spraying for pests. We have put together a checklist, customized for the San Francisco Bay Area to help you. This checklist is adapted from earlier work by Mitsuo Umehara.
This month: March Tasks
Time to Start Repotting
We’re in the middle of repotting season. If you haven’t made bonsai soil recently check out our article on Bonsai Soil Basics.
Warmer weather means more green growth and our trees need a fertilizer with more nitrogen. Refer to Fertilizer Basics.
Pest Control Recommendations
With new growth it’s likely that bugs will show up soon, especially aphids. Refer to Pest Control Basics.
Recap of February Meeting
John Thompson (JT) demonstrated the latest techniques in bonsai grafting along with an overview of what tools you would need and how those tools should be properly maintained to get a sharp “cut” for optimum success. JT is well known for his expertise in technical aspects of bonsai and he did not disappoint. JT demonstrated how a graft could be used to add material to an area of a common juniper to get the owner’s “desired” look for their tree.
Because trees don’t grow perfectly, there are times when grafting is your best option. Those times include when:
- You want growth on really old wood but back budding is unlikely
- You want to change the variety of foliage on a tree, but still take advantage of a strong rootstock
- You want to control the placement of foliage
Different types of grafts work better in different situations and are preferred for different types of trees. JT discussed these types of grafts:
- Thread graft is one ofthe easiest grafting methods. It adds foliage by drilling a hole through the trunk or a limb and threading stock through the hole. (More Details)
- Approach graft to connect two trees (More Details)
- Bridge graft to heal over a large wound
- Channel graft to bring long growth from same tree around to limb somewhere else on the tree. A channel graft can eliminate the bulge problem that can occur with an approach graft.
- Cleft graft typical on fruit trees
- Veneer or inlay graft to add foliage in new areas
The above photo shows a graft that is probably a bit dramatic for a bonsai graft but you can see how it’s important that the cuts be made on both the stock branch and the scion so that the cambiums can be aligned and held in place by the Parafilm that would then be wrapped around the graft. If grafting onto the branch of a bonsai you would want to cut into the side of the stock branch (versus on the top or bottom).
Things you should keep in mind:
- With both grafting and air layering you need to immobilize the area of the graft or section to be separated. Any movement can jeopardize the success of the connection or roots taking.
- Take scions from growth that is a year old. The current year growth is just too weak and you won’t be successful.
- It is helpful to cut back some foliage on old stock so that energy is redirected to the new scion and new growt.h
- Parafilm will keep scions connected to the stock as well as protect the foliage of the scion and keep it moist.
- You must have a very, very sharp grafting knife to ensure a clean cut for the scion as well as the cut into the stock.
- Your cut into the stock needs to be live wood or else the graft will fail. There are tools to help determine if you’ve made a cut at the right spot. JT showed us a tool called Dryease, moisture detector. It rings when it touches live wood.
- You should be able to see development in 2-3 weeks. If the scion turns brown, you know it didn’t take.
- If you see a little moisture collecting in the Parafilm or area where you put it to protect the graft you know the growth is doing okay.
- In 6-8 weeks you’ll see the growth break through the Parafilm.
- Don’t remove your immobilization system too soon. Leave it on for several months.
Grafting knives are important tools. Here are a few things to know:
- Grafting knives come in a right hand or left hand type.
- They must be very sharp to ensure smooth cuts. Jagged cuts won’t “connect” as well and are more likely to fail.
- To protect yourself from getting cut, look for knives that come with a protective plastic sleeve. A folding knife will protect the edge and your hands when stored in your toolbox.
- Grafting knives are sharpened using water stones – same as used to sharpen other bonsai tools. Start with an 800 grit stone. Then progress to finer, 1200 grit and finally finest 2000 grit.
- While sharpening any tool the water stones should not move. To keep them from moving around place on a heavy platform, like a concrete block topped with a sheet of rubber and then the water stone.
- Store water stones in water so they are well lubricated.
Happy grafting everyone! And thanks to Charlene and Idris for both taking such great notes at the meeting.