Greetings! I recently purchased and potted a bunch of Trident Maple and Chinese Elm seedlings. Since Mirai doesn’t seem to do much with these I’m curious if the community has any general tips for developing seedlings into eventual bonsai. Here are a few specific questions I have.
1.) Is it best to “put them in the ground?” People say this is a good way to thicken the trunks more quickly.
2.) At what point is it safe to wire the trunk of a seedling?
3.) Assuming I don’t choose to put them in the ground what size of pot is ideal, and how often do they need repotted?
Any other insight into this practice would be greatly appreciated as well. Thanks!
I would put the seedlings in the ground after a couple years in the pots they’re in. Then slowly fertilize them and prune them with good development in mind until you want to take them out for bonsai (basically when you’re happy with the way they look). If you put them in the ground, a good trick to get a spreading (lateral) root system is to plant them on top of a tile of some sort (stone kitchen tile for example). The roots will grow out and then around the tile, spreading out more in the process. You’ll get some much nicer nebari this way.
I would wire the trunks once they’ve developed some bark, but be careful, trees really do fatten up quickly in the ground, so you don’t want the wire to bite into trunks too much. Just keep an eye on them more than you would if they were in bonsai pots.
If you keep them in pots, I would put them in pots just slightly bigger than their root systems (an inch or so). If you put them into too big of a pot, then it is very easy to over-water them/waterlog them. And, for how often to repot, you repot them when percolation (the flow or draw of water down through the soil) is lost or the growth/health of the tree starts to slow down a little too much. And then when you repot, you put them into a slightly larger pot each time.
Oh, and a couple bits of advice that apply to cuttings…first, I would use some of the rooting hormone powder (or liquid) when you plant the cutting. The rooting hormone helps prevent disease at the cut site. Second, scrape off a light amount of the bark at the bottom (just barely down to the green cambium). This causes the cutting to want to heal itself, and if it’s in the soil at that point, there’s a higher chance of root growth at the scrapes (callus formation, and then root formation). YouTube has a bunch of really good videos on starting cuttings.
I hope this helps! Growing cuttings, seedlings, etc. is fun all unto itself Good luck!