My macrocarpa and bicolor in Michigan put out two flushes every year. No coaxing needed. Pretty standard for oaks I believe. From my experence this occurs after they have been in the ground a year or two. Suggest letting the trees do their thing. I wouldn't cut off anything during the growing season since those leaves are helping build mass. Prune when dormant, that can help you force both growth and form.

i cant hear you ... but i'll read you out ...

a tree at its moist basic.. is an energy storage system for future growth ...

releafing due to stress ... interferes with said normal energy storing... and can slow down long term growth ... hail... late frost/freeze .. etc .. any stress

i dont know why you would consider causing it to happen.. ma nature is mean enough ... on her own ...

the trick with oaks.. is to plant them.. water them properly for the first year ... in drought the second year.. and otherwise try to forget about them ...

when they grow a root mass sufficient for the tree you see above ... in other words.. when the roots match the tree you planted ... they will start growing like all get out .. imo.. it all happens in tree time ... and there is NOTHING you can do.. to make it happen faster ...

i understand it seems like nothing seems to happen the first couple years ... but trust me.. 5 or 10 years later.. its like wow ...

a tree is said to be as much as twice as big below ground.. as what you see above ... so you should understand.. it takes tree time.. to grow that root mass ..

just be patient ...

ken

ps: in other words.. when you have a 5 foot tree in a 5 gallon pot... it needs to grow a lot of free range roots.. to equalize the whole thing... and really get a move on ...

I agree with all the above, Lane. Your tree was probably due to send out a second flush, hail or no hail. The second flush just saved your tree from looking bad for the rest of the season and giving it something to photosynthesize with.

My Q. macrocarpa got hit pretty bad this spring from June bugs, more like late May bugs but this is the first year they bothered this tree.

About one third of the top, only had leaf veins left on the branches and it was only the heavier veins that survived.

By the first half of June, the second flush came on, about the same timing as last year, when there was no damage to the tree.

The odd thing was, the second flush leaders didn't come out from the ends of the first flush branches, like it normally does. I think the reason was, the first flush wasn't hardened off enough yet, to set new buds.

So the second flush sprouted at the base, where the first flush sprouted from. The tree got a 'bushy' look at the top with all these 'double branches' and looked a little 'stunted' too (the damaged branches eventually sprouted some leaves also).

I feel the tree lost some increase in spread and height because of this and may need a little more TLC with structure pruning in the future. Not a big deal, I'm sure in a year or two, you won't be able to notice anything but I thought I'd mention this to let you know that damaging the tree before second flush may not give you the results you're looking for, :-)

Resist the urge! Trees try to balance roots and leaves. If all the leaves go away, tree has no choice but to rebalance by putting out more leaves to feed its now oversized root system. But it does this at a cost - the roots have to use energy they would have used elsewhere to make the leaves... think of it like dipping into savings. If you have to dip into savings too many times, you will run out of money.

Only reason I could see to prune back is to restrict growth.