Seedlings in Containers

mskovan

Rips,
* * *Thanks for responding to my post. There's a lot of info to absorb in that article so I'll just give my first impressions now. I do think that it is a must read for anyone contemplating starting bonsai from seed. Since an impressive root structure seems to be the most desirable and the most difficult thing to achieve in a bonsai the technique of air root pruning in shallow bottomless containers seems made to order for the bonsai grower. Perhaps this technique is common knowledge, but this is the first I've heard of it. It seems to me that this would minimize shock and the resulting retarded growth from repeated depotting. It also is less indiscriminate than simply cutting away a percentage of the root mass. Only the root tips that reach the air are destroyed which, as they say in the article, should maximize lateral development.
* * *An important point made, that I think is counterintuitive, is that there is a point of diminishing return when it comes to pot size. Above a certain diameter/depth relationship you will develop areas of stagnation due to inadequate oxygen penetration. Using a layer of gravel in the bottom of the pot for drainage is another mistake that I am guilty of. When you understand how the water and oxygen exchange take place this makes perfect sense. This article does a fantastic job explaining this.
* * *One last thing for now. You mentioned that most bonsai growers don't have the facilities of the researchers in this paper. That is certainly true in my case. One of the last conclusions drawn in the article is that growing tree seedlings in greenhouses is not recommended. The lack of exposure to wind is a factor in stem development and results in taller and weaker trunks. I honestly think there is a lot of info in this article that could benefit anyone with an interest in bonsai. The focus on obtaining maximum initial growth rates should be of special value to the "bonsai from seed" crowd.
* * *.......Mike