Bonsai Study Group Forum

General Category => Deciduous Bonsai Discussion => Topic started by: bonsaiTom on May 07, 2011, 06:41 AM

Title: defoliating
Post by: bonsaiTom on May 07, 2011, 06:41 AM
When is the best time to defoliate Japanese maple bonsai for leaf reduction?
I'm in a cold region of upstate New York.  The tree is nice and healthy.  I'm considering this for the first time this year.   :-\
Title: Re: defoliating
Post by: MatsuBonsai on May 07, 2011, 08:08 AM
Defoliation is typically used to promote ramification and control/shorten internodes.  Leaf reduction is a side effect, not the primary goal.

For Japanese maples I typically pinch the center growth as it emerges.  Light trimming and removal or reduction of the overly large leaves throughout the growing season should keep everything in check.

Do you have a picture to share?
Title: Re: defoliating
Post by: John Kirby on May 07, 2011, 08:09 AM
Well, I would be very careful of total defoliation. Maybe Bill V will chime in as he is in that general  area as well.

I used to totally defoliate them in Arkansas with mixed results, the way that I have been shown to approach them now is to remove every other large leaf and in cases with trees with lots of large leaves, to cut them in half. Regardless, these techniques stimulate a wound response and reduce energy harvested and sugar (food) produced. Both of which are stressors.

Now the question I should have asked first, is your tree a highly refined tree or are you working towards getting it refined?

Title: Re: defoliating
Post by: bonsaiTom on May 07, 2011, 01:16 PM
Thanks John and John,

Sorry no pictures at this point.  Hot Action-Dave may be able to put up some pictures from our show next weekend.

The tree is NOT highly refined. None of my bonsai are that far along. But I've worked with this one for 6 years and it is one of my earliest attempts with the new hobby.  It's still very much alive  ;D  though I've killed a few others along the way   :-X

After the show I may try one of the methods described above.  My hopes are to have it look much more REFINED than it is for another exhibit that we're planning in early July.

Tall order, huh?
Title: Re: defoliating
Post by: William N. Valavanis on May 08, 2011, 07:33 AM
It has been a very cold, rainy and late spring in Rochester, New York this spring. Probably similar to your weather in the Utica, New York area too.

The best method to develop small leaves on deciduous species is very time consuming, but the results are outstanding and will worth the extra effort. When the trees begin to leaf out, AS, the new shoots appear, simply remove the center developing new leaves, only allowing two leaves to remain. This will develop small leaves, really, AND the tree will NOT need to be trimmed the rest of the season. The tree kind of "sits" there looking pretty. Although you can wait until the small new shoots develop then pinch the centers, earlier removal of the small developing leaves is best. Of course this method of pinching should only be done on developed bonsai where the shape and size is being maintained, not developing bonsai where new branches or trunk thickening is needed. As mentioned this is very time consuming, and remember you don't simply sit down and bud pinch your tree one day. Several days to a week is necessary as all the buds do not open at the same time. Generally, the top section of the tree is most vigorous and that area is pinched first. Then the next day other buds lower down on the tree are pinched as well as any buds missed in the top area. Finally, a few days later the lowest areas are pinched and the missed buds above.

I don't have the time, nor help to do this on all my deciduous bonsai, as I have a tremendous number of Japanese maples, Trident maples and other species. So, what I do is to select a few to bud pinch, keeping in mind which specimens I plan to display the coming year (including winter because the internodes will be very short) and to photograph for my upcoming 50th Anniversary Commemorative Album. This season two Japanese maples, three Golden full moon maples, a couple of Trident maples and a couple of other deciduous trees are still being bud pinched. I just started to bud pinch the Beech, as they are always the last species for me to leaf out in this area, and they are a bit MORE time consuming as they must be bud pinched twice a day, morning and afternoon. Those long, sculptured beautiful buds move quickly and a few hours makes a big difference. But remember, you will not need to trim your Beech bonsai for the rest of the season.

Before bud pinching, and defoliation too, the tree must be trimmed and thinned out perhaps. On Wednesday it took me (and I work quickly) four hours to thin out one of my beech bonsai. It's important to remove the terminal bud on each twig on Beech bonsai. This takes the tremendous energy stored and directed to the large terminal bud and redirects it to the smaller buds behind. My large single trunk Beech was trimmed on Wednesday and put in the cold dark garage to hold it back before transplanting, which I will do today or on Monday. It is just sitting in a new larger container, but the rootball is intact and very safe.

I like to wait at least three weeks after deciduous trees (mostly Japanese and Trident maples) leaf out and mature before complete defoliation. It's important to fertilize before defoliation and the tree must be healthy. It does not matter if you have recently repotted, if the tree is healthy and vigorous.

When defoliating deciduous bonsai it is important to keep the trees in as much sun as possible (NO shade) and to hold back on the water a bit. There will be no leaves after defoliation, so the tree will not dry out as much.

He in the Upstate New York area I defoliate my deciduous bonsai from early June to mid-August, allowing the developing new leaves time to mature before frost.

So Tom, I suggest you display your bonsai as it is now, then defoliate and perhaps use a different specimen for your other show in July. I hope to see you at the 38th Upstate New York Bonsai Exhibition in Rochester, New York on May 21-22nd.

Title: Re: defoliating
Post by: bonsaiTom on May 08, 2011, 09:52 AM

A huge thank you for taking the time for your detailed response. I'm sure many of us here will benefit from your advice. I'll proceed with caution and now I have a much clearer plan for the future with this tree.

I don't envy your work load with the 50th anniversary quickly approaching.

I have a family wedding commitment on the 21st but I'll try to come out on Sun.
Title: Re: defoliating
Post by: scottroxburgh on May 09, 2011, 06:42 AM
Very informative Bill, thanks for your time.
Title: Re: defoliating
Post by: bonsaiTom on May 10, 2011, 06:43 PM
Hey Bill,

Turns out I will be coming on Sunday, with a car full - but with my Mini Cooper that's just 2 - gotta leave some room for purchases!   ;D