Opposing leaf newbie

[WimA]

So... I'm posting this newbie question here as I consider the maple the prototypical opposing leaf tree species.

From an idealized esthetic view, bonsai are not supposed to have bar branches and branches should alternate (I realize this might be controversial/untrue/..., but please go along with the presumption for now). Does this make opposing leaf species less suitable? I guess not, since many opposing leaf species are very popular. Is this solved by pruning? When do you prune? To what level do you prune (e.g. only major branches, only minor branches, down to leaf level)?

I've tried reading some books, but haven't figured this out, so I'm counting on the incredible collective wisdom here

 

[sorce]

It makes them less "set it and forget it" for growing out.

You're usually just cutting the center shoot out.

Sorce

 

[WimA]

That makes sense. Next question is... When? As soon as possible? When the leaves have hardened off? In dormant season?

 

[Shibui]

Opposite leaf types give more options. You can remove the centre shoot or either one of the side shoots. Both achieve the Y fork required and that's 3 options at every node. Removing the centre shoot usually helps with taper. Removing a side shoot can help with building alternating branch direction.

In practice I rarely just remove one or the other. That usually leaves an odd shaped junction. I find it better long term to remove 2 of the shoots and leave just a single side shoot. That may sound counterproductive but I usually get lots of new, smaller shoots emerge from the node after pruning like that and some are far better placed and thinner than the original shoots.

There is no single correct answer to 'when'. So much depends on the individual plant, what stage it is and what time of year. I pinch the centre shoot of JM and tridents as soon as possible in spring on really advanced trees but usually wait until after leaves have hardened or sometimes a year or 2 to select shoots for developing trees.