Friday, May 15, 2020

Alnus Serrulata #1 - Smooth Alder

This little Alder tree has quickly become one of my favorite since starting it last year. I collected the seeds in February 2019 from a tree on the edge of a field. I had read that in nature, alder seeds fall into creek and river waters and actually float down the river, germinating while floating in the water. I attempted to mimic this germination process by taking the seeds and leaving them in a cup of water.
 





A bunch sprouted roots in the cup of water. I only had one spare seedling cell and not a lot of room on my windowsill to give them light at that time, so I planted eight or nine of the seeds in the available seed cell. Unfortunately, of the eight or nine that I took out of the water and planted, only one seed survived. The other seeds dampened off (a common fungal disease affecting newly germinated seedlings).

Left: the seedling as it was after germination and allowed to grow for several weeks. It was tiny, yet showed promise as it quickly grew and gained strength.Within about five or six weeks in this cell, roots had begun to grow out the bottom of the cell and the tree needed an upgrade into a bigger pot. The leaves of the tree very small, indicating a good possibility for them to slowly reduce over time. Alder is not used much for bonsai, but it shows a lot of promise to my eyes.


The seedling was planted in a small terracotta pot sometime in early June. I used a process called 'slip-potting' for this transfer, simply removing the alder from the smaller pot, and backfilling around the roots in the larger pot with additional soil. This means the roots of the tree aren't impacted much. As expected, the tree wasn't affected at all by the summer repot. I would not normally repot the tree at this time if I was doing more significant root work. I even saw the beginning of branching starting to occur.

By the end of the summer, the tree had grown incredibly strong. An emergency repot in August was necessary when the terracotta pot was knocked off the  benches where I keep my trees. This had happened while I was at work however a rain shower that day kept the tree's roots wet enough for me to be able to put the tree in yet another pot when I got home with no issues. (Left) The tree in October started to go dormant and lose it's leaves. It didn't put off much color, which was disappointing, but the loss of leaves revealed a mature branch structure for a tree just under one year old.


I repotted the tree again this spring at the proper time, just as the buds were swelling. I did some minor pruning as well, removing a few branches that were unnecessary for the long-term design of the tree. I'd like to try and keep this tree rather small. The roots looked great, with a really nice root spread. At the close of March, the tree leafed out. The little red buds all over the tree putting out new growth in unison. Long term goals for this tree this year are to further thicken the base of the tree and eventually choose the branches which will become the main part of the structure. 

No comments: