AusBonsai

Ramification and leaf reduction on common Ash; Fraxinus angustifolia

Hi all,
I just got a request via PM about how to ramify an Ash; so I thought I would share my thoughts with everyone.

Step one. Make sure the tree is very healthy with frequent repotting, slow release fertilizer in the potting mix, slow release fertilizer drizzled around the edge in its second year of growth in the same pot and regular fertilizing (every 10 to 14 days) with a liquid fertilizer of NPK with N somewhere in the 10 to 14 range. I also mix in Seasol and both products are used at full recommended dilution strength (not half strength).
Also make sure the pot is big enough to allow the tree to grow freely for a couple of years without it becoming totally root bound or drying out too quickly (which may set the tree back).
This all may seem counter intuitive to getting smaller leaves but it is part of an intensive program.

Step two. Try and keep as many branches as you possibly can without destroying the shape or allowing swelling where numerous branches come from the same spot on the trunk. Cut off what you have to but by leaving as many branches as possible you are starting to diffuse the vigorous growth induced by step one throughout the whole of the tree. Scars should also heal quicker with many branches and leaves helping the trunk to fatten and heal at the same time.

Step three. Defoliate as often as possible in your climate. This helps stimulate back budding by totally removing all foliage and just leaving the stalks behind.
Defoliation alone is not enough but when used wisely with other techniques it really makes a difference.


Step four. After defoliating; wire everything! (Here I am talking about the style where all the branches are wired down). By having kept as many branches as possible you are less likely to get wire cutting in too quickly as all the many branches are gradually thickening.
Now by wiring everything down and defoliating at the same time you really start to stimulate the back budding internally of branches. By lowering the tips of the branches and defoliating you are allowing the sun into the inside of the tree but as well the lowering of the tips induces the trees hormones to stimulate the portion of the branch that is now higher than the tips.
As the tree comes back into leaf each time nip out the tips of the strongest growth as quickly as possible but allow the weaker portions to elongate to say four or five sets of leaves and then cut back to just one set of leaves or leave it slightly longer if you are going to now wire it down as a new branchlet. This should distribute the vigour evenly throughout the tree.

Step five to fifteen. Repeat steps three and four as often as you can to build up a ramified structure that should give you smaller leaves as well. You will gradually do less wiring down of internal tips and just cut back to one or two sets of leaves as you trim back the new growth.

Finally and eventually you will probably trim off some of the lowest portions of each branch as these will have become elongated away from the trunk and you now compact the overall silhouette of the tree.

Grant

Thank you for the concise info Grant. Getting it from one who knows the process confirms that i am on the right track. Tedious work though wiring everything down, but thats how you get the great tree, by the amount of work you have put in. Thanks again.

bodhidharma wrote:Thank you for the concise info Grant. Getting it from one who knows the process confirms that i am on the right track. Tedious work though wiring everything down, but thats how you get the great tree, by the amount of work you have put in. Thanks again.

Hopefully (or it is to be hoped that...) after a few years the process will become less wiring and more trimming off of large leaves and even leaf trimming the compound leaf back to one or two leaflets.

Grant

I would presume that your methodology would apply to most Ash's Grant I have a problem with back budding on my oxycarpa but have been trimming back to two sets of leaves for a few years now, will that hinder the back budding process. The tree has a very mature trunk and i have been trying to improve its ramification for a while now but back budding is an issue. The tree is very healthy (can post a pic if you like) and i am more than a little disappointed with its back budding.

bodhidharma wrote:I would presume that your methodology would apply to most Ash's Grant I have a problem with back budding on my oxycarpa but have been trimming back to two sets of leaves for a few years now, will that hinder the back budding process. The tree has a very mature trunk and i have been trying to improve its ramification for a while now but back budding is an issue. The tree is very healthy (can post a pic if you like) and i am more than a little disappointed with its back budding.

Hi,

One of our very senior members here in Canberra had the same problem with an Ash that was not exactly Fraxinus angustifolia; but as it was a seed blown in form somewhere in his neighbourhood it could be anything although it looks like angustifolia. The trunk was old but not as rough as angustifolia.

He is however having better success this year but still not as well as mine. The first time he tried a defoliation it really struggled but that may have been due to lack of vigour due to lack of adequate fertilizing.

Just keep trying is my advice.

Maybe try partial defoliation to start with in late spring/early summer and see how it goes.

Grant

Just linked this page in the Wiki as it has some really good information.
Thanks Grant - I hadn't seen this before.

Just to add something to the above method.

Always remember to pinch out,cut the terminal bud of every branch and branchlet along with the defoliation.!!!!!.If you don't do this the branch will just continue to grow as before defoliation and you will get no back budding.

Grant