AusBonsai

Hi everyone. Just at the outset I'll let you know that I am quite a noob at bonsai and have a lot (a lot, a lot) of knowledge missing. I had known about bonsai for quite a long time and thought they were cool but hadn't had the patience as a teenager to start getting into it properly, but now I am in my twenties and I really enjoy what I've been finding out and practising.

But anyway, getting to the point we have a Japanese Maple in our back garden and it dropped heaps of seeds (as they do) and one of them started growing quite well as a seedling in the garden so I took it when it was big enough (roughly 15-20cm) and put it into the nearest pot I had which is kind of large. Since then it has been growing rather vigorously and making new shoots everywhere and getting taller and I've been trying to train it not to grow such large leaves by selective pruning (to some small success) and also have been trying to get it to sprout something in the lower branch department by pruning the top (it quite likes just growing its canopy). I was just wondering as it is still the growing season and it just keep putting out new shoots and leaves, whether it is practical to defoliate a seedling. It is not roughly 30cm tall, has quite a many leaves and the trunk is probably 5mm-ish.

Any info or just general tips on growing this plant would be helpful!

Thanks!

Hi Safallon , it all depends on what your after in the tree .Do you want a 300mm high bonsai of a 500mm high bonsai ?. Do you want a single trunk tree or multi trunk ? Broom style or inforal upright ?. These decision are made with the growth of the tree/trunk in mind or have to be pre trained . Yes its a seedling so it will have vigour , removing the tip will promote and stimulate side shoots which should slow the rapid single growth down somewhat but will still have vigour . Trimming the new tips again will promote newer growth and thus force more shoots .
I can't see any reason why a seedling couldn't be defoliated but i would be inclined to let it grow and keep cutting it back to get some thickness into the trunk . Defoliating will slow the root growth on a small seedling moreso than a developing tree which already has a developed root mass to feed the canopy .

I have defoliated 5 yo Japanese Maple chop top trunks during the rebuilding of a completely new set of branches and canopy. First and foremost i had to have a good root mass , then i needed the new branches in the correct positions before i did any defoliating .After the first year with a 40-50mm trunk { big stick in a pot } i had an outlined structure of new branches , for the following several years i defoliated them up to 6 times in a season , 7 times and the tree will almost certainly die .
I was told and have read it couldn't be done more than 2-3 at the most with a strong healthy plant/bonsai. The tree will stall without leaves and the water nutrient uptake is vastly reduced so it can drown and rot in a short period so care must be taken with watering . Personally i would let it grow 5-6 sets of leaves then cut it back to the 2nd set , this with help fatten the trunk and still keep you busy trimming and keeping the foliage in check .

Next year would be worth trying defoliating as it would have a good root mass developed and you should have a well defined starter with an outlined canopy ,style or design in mind .Wiring need very close monitoring as wire marks in Japanese Maples take years to conceal .All the best with which ever plan you take .

Cheers Alpineart

Thanks a lot for your comprehensive information! It's really good just to have information from experience about particular species right at hand. I have pruned off some of the top growth and clipped some of the larger leaves away. The trunk is actually getting fatter faster than I originally thought it would. It is a seedling from the spring's seeds and it is already so strong! I took a photo for you.

Hi Safallon , mate just keep cutting it back to the second set of leaves and it will continue to sprout even from the lower section where the old leaf nodes are , this will help fatten it more . In a season or two you can have a trainer with numerous options . Just be careful if you wire it as the wire marks stay with a Japanese Maple for years .

All the best . Cheers Alpine