Encouraging/Maintaining Adult Juniper Foliage

I have a small Itoigawa Juniper that I have recently styled. Before hand, it had a mixture of juvenile and adult foliage, but during the styling, all of the juvenile foliage was removed. It there a technique that I should use to ensure that only adult foliage grows in the future or is the tree likely to continue to grow only adult foliage now that all the juvenile leaves have been removed?
Thanks, Lee.

hi Lee,

itoigawa will go through quite long periods of producing juvenile needle growth then finally settles down and makes a higher percentage of scale growth. it is a tree that needs a little more patience than other junipers

the trigger for the juvenile growth seems to be mostly linked to pruning back and styling although following repotting it can increase too. Stressing causes lots of it too, so i think all these procedures cause stress so potentially the juvenile growth is stress related. I have a club members tree here in 'hospital' care that was pale yellow with severe root rot when it came in, and every shoot was juvenile with very small amounts of adult growth on the ends...all inner shoots were needle too. A year after repotting and giving tlc the tree is settling down, colour has recovered and some of the new inner shoots are just beginning to come through as adult.

i think itoigawa styling needs to be done with a clear idea of the final design so you put the tree through one major styling then you put up with the mixed foliage for a few years while the tree settles and recovers. Just cutting off the needle growth will not get you to the adult stage quicker though as the tree gets all its strength from the foliage so removing too much excess foliage keeps the tree in a permanently weaker state, so adult foliage production will be held back longer.

the pattern seems to be: all needle growth on thin weak shoots, then needle growth with adult on the end - (this is a sign it is getting there but not the foliage to build the final pads from though) - both these stages should not be cut off for the sake of it. finally adult shoots start coming from the actual branches - now you gradually thin the needle shoots to give light and air to the desirable shoots....and never ever pinch - use scissors to cut back neatly to an inner side shoot as this keeps the foliage tips intact.

cheers Marcus

What Marcus said. I addition, I could never find anyone explaining to me how to trim a juniper and still maintain the mature foliage. I found ou myself:

Juniper will react to anthing that throws them out of balance by shooting juvenile foliage. Juvenile foliage as opposed to mature foliage has more surface area for photosynthesis. So the clue is to avoid stress. How do you avoid stress in general, whether its trees or live? Any changes should be introduced gradually, with time in between. So when you need to trim back mature juniper foliage, trim back the tips first, not the sidebranches! Let's be very clear on this, you do not topiary prune, you treat the individual shoot! So, you are trimming the tips first, no more than about 1/3 of the branch(let). Then you come back after you see some bud movement and trim another 1/3 of the main shoot. During this second trim you may get also some sideshoots growing off the main stem. This may give you the desired length. If not, you again wait for bud movement and trim back the main shoot. Try to leave the most basic or first sidebranches (branchlets) on the tree. They are the "wise" ones. That's whay they are there to begin with. They make sure you don't get the juvenile growth. f you were not able to leave some of these, don't worry. The few juvenile shoots will reverse to mature growth during the next (few) growing cycle(s).

Best,
Dorothy

Thanks Marcus/Dorothy.