shibui wrote: ↑March 25th, 2022, 7:50 pm
I suppose it depends on the results you want.
100% agree with Shibui.
If you just plant in the ground and let the tree go, you will end up with a large garden plant that is often not conducive or helpful for development into a
quality bonsai. The idea of planting in the ground is to "speed up" development, but the development work still needs to be done, and as the tree is growing so fast, this will entail more work than a tree that is pot grown.
It took me two decades to figure out what to focus on when ground growing stock, and it is different for each species (for me).
Here are some pointers that I use (hope it is helpful):
Deciduous (especially tridents):
No.1 focus is nebari. - I usually set the direction of the nebari before planting in the ground at about 3 years old. This involves annual severe root pruning from seedling to 3yo to establish radial roots before ground planting. I even discard trees at this stage that are not playing ball, as they will be difficult to rectify. Once in the ground, lift every year and shave back root system to maintain radial, shallow spreading roots (I also lift elms every year). Fill gaps with root grafts before replanting for another growing season. If you fail to lift every year, one single running root that excessively thickens can ruin the nebari.
No.2 focus is taper. Failure to form taper defeats the purpose of ground growing. I cut back most deciduous every year to the lowest possible
node to guarantee a healthy rebudding leader - after one year in the ground, the chopped leader of a trident is usually about an inch thick. If this cut is shaped nicely, the scar is usually healed in 2 years whilst in the ground and developing.
No.3 focus is maintaining the lower branches - you will need them later. I keep them well pruned and ramified to prevent over-thickening, but maintain a healthy amount of foliage so they don't die back (energy balance).
JBP:
No.1 focus is maintaining lower branches. - pines grow so fast in the ground that girth will look after itself, but failure to preserve lower branches will result in a thick, spindly tree that is not conducive to quality bonsai. Achieve this maintenance by decandling, ramifying and maintaining foliage on the lower branches without letting them thicken too much, but maintaining a healthy amount of foliage (energy balance).
No.2 focus is planning the next trunk chop - you need trunk chops for taper. I let the sacrificial leader grow until it is the thickness I desire - 1, 2 or maybe 3 years. However, I never let the sacrificial leader grow before I have established a bud or node to cut back to for the subsequent chop (planning ahead). Sometimes this requires decandling of the leader to establish this budding and short node length for the next cut site before I let it run, which will slow development for that year. But if you don't do this, down the track the node length will be too long to enable establishment of taper and branching close together, and you will end up with a tall, sparse tree, rather than a tapered, compact, fat tree.
No.3 focus is the roots - As with maples, I spend about 3 years establishing a good root system before planting in the ground. For JBP, this is less about nebari, and more about establishing a "shin" (fibrous root system directly below the trunk). I then plant inside a colendar in the ground, in a good porous soil mix, as it makes it much easier to lift later on. I don't lift pines every year - in fact, I don't lift them at all during ground development. The reason for this is that pines are the fastest growing species in the ground, and pruning development (sometimes quite harsh pruning) is needed to keep them in check. If you lift the pines, the root pruning in the same year as branch pruning, decandling and needle plucking for balance will cause it to suffer. So I prefer to redevelop a nice fibrous root system once they are lifted (even if that is say after 10 years in the ground).
Junipers:
I don't ground grow them, as I have observed little difference in speed of development in the ground or in a pot.
Either way, after 10 or 15 years of development, you will most likely need to graft branches to establish a bonsai from the developed trunk anyway.
I don't find them as rewarding to develop as other species, as they are SLOW to gain trunk girth. I get about 2 inches of girth every 10 years . I can get this girth in less than half the time with elms, tridents or JBP.
That is likely why the Japanese only use collected material that are hundreds of years old.
Hope this helps.
Cheers
) All have survived transplant with huge root reduction as have most in the past. I've tried digging then chopping the tops and also chopping tops a few weeks before digging. Does not seem to be much difference in survival rates. As mentioned earlier dig in late spring in my area.