To start of with, I should say that I am a novice, especially in the arena of growing japanese acer tree's.
18 months ago my wife asked me to try and propogate from our reasonably established acer, as we were (and hopefully still are) going to move house and we cannot take the main tree with us. So, I collected some seeds (only 20 or so) and sowed a couple each in 10, 7cm pots, in the appropriate compost.
Two germinated and they are doing well as tree/seedlings. The trouble I have now, is that two further seedlings have emerged this March, and it's ironic that they have germinated in the same pots as the earlier seedlings. The issue therefore is space and transplanting and when I should do it.
The space between new seedlings and established 1 year old "trees" is about 3 or 4 cm's in both cases. Being a novice, I am worried that the root systems may become entwined and I should transplant the newly germinated seedlings asap. Is that wrong? I have read that root systems/tap root is shallow and I should wait for a full season until dormant, but is that the best advice in my case?
Should transplanting (given proxmity to main seedling) be a cautious affair, as I imagine it should be.