Monday, March 16, 2020

Malus Clump #1 - Crabapple

Last year I started these three Crabapple trees. I gathered the seeds from a gas station tree in Harrisonburg, Virginia while playing a show with our friends in Earthling and Disintegration. Germination for these was the same as pretty much any seeds you would get for anything in the malus family. I refrigerated the seeds in a damp paper towel for approximately 30 days. After that point, I checked them every week to see if any were sprouting roots. When these three seeds began to sprout roots, I moved them into these starter trays. The soil I used here was regular garden soil mixed with compost. In about two weeks, they started showing their first true leaves.

Due to a lack of light set up, these seedlings looked leggy (long) which reinforced to me the need for a better lighting setup. Either way, they managed ok in the window sill until some warmer weather rolled around. Were I doing this now, I would have waited another month to stratify the seeds. Germinating and getting strong growth indoors is difficult. It did gain me about a month of growth, because they germinated in February instead of the mid-late march which would be ideal, but it's not something I would recommend without a proper propagation light setup. These were some of the first stratified seeds I had worked with.

By late March, I was able to repot them into a bigger pot for growing out. I put them in a standard terracotta pot. For soil, I used Napa Oil Dry 8822 as a substrate. The trees seemed to do very well initially. I encountered very few issues. Once in a while, I would see some aphids on the leaves which I would simply pick off or squish. Crabapples are generally considered disease magnets because of their 'sweet' wood. Insects love them.

By the end of July, the three trees had put on strong growth all summer and were doing very well. The roots had grown so vigorously that water was not draining well in the pot. I punched a hole through the center of the root ball just to give some drainage capability. Fertilization consisted of two applications of osmocote slow release 14-14-14 fertilizer and, towards autumn, occasionally liquid fertilization at low amounts.

By early November, the trees had pushed their fall color - a deep greenish red, almost purple hue. A second flush of growth through late August, September and early October was unexpected but brought the trees to about 14" high each. By this point, I had decided that I would be repotting the trees in the spring again, because I wanted to solve the drainage issues.

I also wanted to get the trees as close together as I could to attempt a fused trunk clump to form. Inspired by old landscape crabapples I've seen with massive triple trunks, I waiting through winter until the first signs of enlarging buds on the trunk indicating the ideal time to repot deciduous trees. These were overwintered by digging the pot into my vegetable garden beds to keep the root ball warm.

Removing the tree from the pot, it was immediately clear that the tree needed to be repotted. Matted roots filling the bottom of the pot were healthy but clearly confined. Raking out the roots and soil to get a better idea of what kind of structure I was dealing with yielded an almost springlike structure of thick, healthy roots. This root growth shows what kind of excellent root mass you can get in a single year.

I simply cut the entire bottom of the root mass off and got individual trees separated. Even removing all the matted roots proved not enough to easily separate the trees. Tangled masses of roots for each tree intertwined and wrapped around each other. I did my best to clean up the roots for each tree, removing roots growing in directions I didn't want. Because my plan was to fuse these three trees together, decided the best front of the trees, and used that as a guide as to where I could remove more roots. I needed to be able to get the base of the trunks as close together as possible. I removed roughly 75% of all the roots that the trees had grown the past year. I was perfectly fine with this and expect the tree to fully grow them all back - and more - by the end of this year.

In order to get the trees into the alignment I wanted them to fuse together, I made a wooden template out of shims to keep the trees separated from each other. I notched out a spot for each tree and pushed it down into the middle of them. I then arranged the roots outward as best I could in the direction I wanted them to grow. You can see in the picture to the left how radical my pruning was on the trees. Once I had the trees in a decent general position, I zip-tied them together to make sure they don't push apart as they grow this year. My main goal is to let the roots establish in this formation.

Next year, I will do a less severe cut back of the roots and attempt to scar the surface of the trees where they come into contact with each other so that their cambium layers can fuse into each other. This would be similar in function to a graft. By allowing the roots to grow into each other this year, next year I can remove the zip tie and use wire to hold the location of the fusing together.

March 3rd, 2020

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