Having used this approach over five years and with some trunks now approaching 1.5 inches in size or more, the approach does work very well.

The colander also allows lots of air in for the roots and using Boon’s soil (akadama, pumice, and lava) with lots of fertilizer increases the girth very quickly.

Nice trees Jonas.

That said, growing pines in colanders requires a lot of water as they dry out more quickly than pines in terra cotta pots. Your choice may depend on hot it gets where you live and how much you can water.

Best Regards,
Josef

I am a fan – terra cotta pots are great because they are porous and because they are inexpensive. Plastic containers don’t encourage new roots like terra cotta, and bonsai training pots are more expensive. Training pots are great when trees move from trunk or branch development to more refined development – many of my trees are in “training pots” or similarly inexpensive bonsai pots.

As for the drainage hole – you’re right, one hole is rarely enough. I drill all of my terra cotta pots to provide holes for securing the trees. Usually I add 4 small holes, big enough to let wire through and help with the drainage. Sometimes I widen the main drainage hole at the same time. A “hole saw” (drill-bit used for making large holes) is great for this task.

One note about terra cotta pots. The most commonly found terra cotta pots available in nurseries are usually unnecessarily deep for bonsai. I tend towards the more shallow pots to encourage the lateral roots.

Thanks for the questions,
Jonas

Thanks for the helpful reply. I hope you won’t mind a couple more questions. I see lots of pre-bonsai in terracotta pots in the images from Japan, and it looks like you are a fan of them too. Do you think that they are the best type of training pots? Also, most I’ve seen only have 1 drainage hole, so how do you prefer to secure the trees? Like a cascade pot? Thanks again for this wonderful blog and your help.

Josef

These pines have been container grown from seedling-cuttings for the entire 15 years. For smaller trees, container growing can yield nice bonsai. For larger trees, growing in the ground is useful to thicken the trunk more quickly. When you move from container to ground or back again isn’t as important as knowing what your goals are for the tree at any stage of development. If the trunk needs to get bigger fast, the ground is a good bet. If more refinement is needed, containers are the only option. I’ll be writing a lot more on the topic as time goes by as I have plenty of young pines in development – most in containers and one larger tree that started with 10 years in the ground before the refinement began.

Jonas

After starting these trees from seed, where/how were they grown? In the ground, in large pots? A combination? I am at a bit of a loss as to when the transition growing methods and locations when growing on a young tree. Mostly I am interested in the propagation of deciduous material, however. Any advice you could offer would be most appreciated. Thanks!

Best,
Michael