Pruning of deciduous trees in the growing season

[Bretts]

There has been alot of discussion about total defoliation of deciduous trees in the past couple of years.
If I can be so bold to state that alot of this has come from Grant and I gather this has been inspired by the teachings of Don Delaluca who has shown what seems to be amazing results especially with ash trees that are defoliated several times a year.
Yet this seems to be in contradiction to recent teachings of many learned enthusiast that state defoliation is not the way to go.

I am starting this thread to debate and work through if and when defoliation is a good practice and what other options may be a better practice.
It is hard to deny the results we have seen with multiple defoliation on ash trees so why are our learned peers saying defoliation is not good practice?

[alpineart]

Defoliating does improve ramification say on a Japanese Maple however i wouldn't do it to a Trident maple , i would simply cut back and trim .There are 2 completely different growth habits .I continually prune Crab Apples monthly , pinch and grow if you like or i would have to cut back hard at the end of the growing season .Building a tree and refining it during the growing season will giving multiple results . more branches/shoots . Trimming at the end of the season will give a single result , a bigger thicker trunk for starters . Defoliating stimulates back budding or premature budding of the buds that are already present .Cutting back on a Trident Maple or a Crab Apple will do the same .

As a teenager i was taught by an old timer to cut fruit trees once to an outside bud and grow for a year , now they cut and trim 2 -3 times a year depending on the area and the species so the energy is spent producing more branches which i turn produces more fruit , ei Ramification ,its a bit hard to defol 50 acres of fruit tree's .As a youngster I actually got sacked because i basically cut them back too hard .Nowadays they do exactly that cut back hard , build the structure that produces twice as much fruit on a smaller tree. Whilst their not Bonsai the same principle applies . I was doing this long before i joined forums or knew about bonsai as such .That chap that taught me was of an era Long before Grants time and i haven't read the teachings of Don Delueca , couldn't even tell you where his from .

Once again its easy to quote other peoples work written or trialled but you need to try it yourself in your area and with numerous specimens not 1 or 2 plants but 20-50-100 .then you will have a conclusive result . . In a well know book it states to only defol a Japanese Maple 1-2 times in a season maximum . I have already done mine and are about to do them again this weekend , i do them when i think they need doing not when a book say to do it . Morning , noon or night and has had no effect on the recovery My tridents are about to be cut back soon , just need to get back on my feet , another accident another broken bone , this time its the left foot , so now i'm really dragging my feet .

Cheers Alpineart

[Scott Roxburgh]

None of my deciduous trees are at the defoliating stage yet. Many are still growing secondary branches, so defoliating will just weaken them and lose the vigour that I could use for extension/thickening.

Currently, most trees are growing out with heavy fert to gain strength and I will shortly cut them back once in summer.

I feel that many are too quick to start defoliating young trees. I think that defoliating does have its place, but not on young or weak trees.

[DavidN]

Great topic of discussion and very good timing too.

I have read alot and talked to a number of knowledgable people regarding defoliation in our climate. I only defoliate once a year. I have a number of trident maples that are at the stage of trying to force tiny foliage especially to try and ready them for the AABC Convention Exhibition in May. Over the last few weeks I have defoliated all the advanced trident maples that are ready for show . I have had some good results and one unexpected result.

The good results were that the leaves have come back smaller and the inner weak shoots have become stronger. These trees I will now be vigilant and trim off any large leaves that appear and pinch back any extended growth(standard practice on pretty much all decidious trees). On one tree in particular the leaves are almost a quarter of the size plus this tree did bud back and produce lots of twigs. The unexpected result on one tree was that the leaves have come back just as large if not larger!!! Not sure why yet.

So, on whole, I have found defoliating just one further step/technique to helping my tridents achieve smaller leaves and back budding, however being vigilant and conitually pinching after defoliation is very much required to make the tree look its best. You can't just defoliate and think thats all I will need to do to achieve the result I am after.

David

[bodhidharma]

Alpine has covered it very well. Some trees will be capable of thriving on multiple defoliation and some not. Some trees will give you smaller leaves and some not. If we look at an English elm, after a while it will grow smaller leaves even without defoliation. An elm i have will produce small leaves the following year without defoliation if i do not repot it. Unfortunately, on the third year, it starts to suffer badly.For Elms i have found the formula of repotting and defoliating once yearly is the best practise. With say, Corylus avellana, the hazel or twisted hazel defoliation results in it going dormant or it produces buds and they sit there and do not turn into leaf. Next year the leaves come back bigger. The upside is, you get more catkins the following year. Some trees, After a long time in a pot culture, naturally produce smaller leaves. Good thread and looking forward to more input.

[Luke308]

In regards to Maples (Japanese and Tridents) Peter Adams book on Japanese maples covers the pros and cons of each method of defoliation. I.e partial or total. If you don't own this book, I would highly recommend it, or at least borrow it from your local club library. From memory, I think he says you shouldnt totally defoliate a tree 2 years in a row. but dont quote me on that.

http://www.ebay.com.au/itm/Bonsai-Japan ... 45fe7ded2e

[NBPCA]

Remember to find out where people live and assess their information.

Defoliation might only be done every second year where growing seasons are short or temps mild for instance.

Assess how healthy your trees are as well.

Grant

[alpineart]

Hi Luke , My 3 Japanese Maples have been defoliated a minimum of 4 times per year since i began building them , probably 4-5 years now .I have his book , no offense to the Author but his from England is he not , and their heat wave is 20 degree's so that throws that theory is out the window . Most printed material is printed for the Northern Hemisphere and applies to the conditions in Northern Hemisphere , Not to the Land Down Under . Don't take that sort of printed material as gospel .Unfortunately we don't have a great deal of Bonsai literature printed here for Aussie conditions . There is probably more on this site reguarding our varying conditions than anywhere else .

Cheers Alpineart

[GavinG]

Scott's got the important bit - defoliation is ONLY useful at the refining stage.

If you've just done a trunk chop, and what grows from there is still weedy DON"T DEFOLIATE! Grow it long and strong, cut back, repeat, until you have a convincing, multi-directional, multi-stage taper. Take your time.

If you are just starting to develop branches, grow them long as well, and cut back. Get strength in them, in proportion to the trunk.

When that's all done, ramify the fine endings. That's when you defoliate. It's just a technique, not a magic bonsai wand.

Does anyone defoliate plums? I've got trouble with cerasifera - if you prune it back to two buds, only one bud will shoot. Would defoliation encourage more buds to go, or would it just sulk? And what about camellias and gardenias?

Gavin

[Dario]

Hi all!
Regardless of location and climate from what I have read, I think some don't believe in "total" defoliation (but may practise partial defoliation), as from a horticultural stand point they see it as too severe a stress and drain on the trees energy and health...forcing it to play catch up and to try to regain some of the lost energy via totall defoliation.
This is not my belief as yesterday I defoliated a small ash I am working on.
Gosh Alpine...another broken bone?...what can I say...get better soon mate!!
Cheers, Dario.

[Bretts]

Thanks for all the great input guy's
The work that was meant to start the other day is now starting tonight so although I may check in with the mobile I might not have alot to say over the next week because typing on the phone is not much fun for me

I can only think of myself as a student with many teachers. This with various climates that I think will be a big issue in working out why there are various opinions on this.

Alpine, Don DeLuca lives out at Hay in very hot conditions. He is a good friend of Grant's as well as many others in the community. I don't mean to imply that Don is the inventor of defoliation. What I do know is he explained to me that with his hot conditions he decided that instead of allowing the sun to burn the leaves off his trees several times a year he would take control of this and defoliate the trees himself several times a year. He was the first I had heard about multiple defoliation's in the one year. At last count I think 5 times a year for the ash tree.

Oops running out of time been on the phone.

The problem I have is some very accomplished nurserymen are now stating that defoliation is not the way to go. Tridents especially but it also seems to be with many other varieties as well.
I was trying to upload the Ryan Neil vid where he states defoliation is not the way to go. From memory he used Japanese maple as an example but I have been cut to dial up speed for the month and did not get that far into the vid to double check.
http://www.youtube.com/watch?v=KJq4PWe6jQo
Also in the latest Bonsai Focus we have this from an article about shohin.

An often misunderstood technique is to totally leaf prune deciduous bonsai, or perhaps it's one of those earlier learned bad habits.......

It goes on quite considerably stating such things as actually making inter nodes longer than a better pruning method that I don't fully understand yet.
Sorry to leave this there but I have run out of time.
Might not be back for a week so enjoy the time without my babbling but I will be watching

Edit been a few posts since I started this sorry I had no time to read at the moment

[NBPCA]

We are progressively getting shorter internodes on our Japanes maples as the years go by. In some places down to about 5mm.

I have also recently discovered that Japanese maples can be cut back beyond the first set of leaves; sometimes to a ring just a millimeter or two from the original bud even though the first set of leaves might be 20 or 30 mm further down.

As the trees age and we get more branches we will naturally get shorter internodes and the need for defoliation will be lessened but not eliminated.

Defoliation also helps with distribution of vigour in the middle of the growing season.

Internodes.JPG

Grant

[EdwardH]

I think that it's important to remember the reasons for defoliation. There are four that I am aware of
1. Improve ramification
2. Redistribute strength or vigor in a tree
3. Reduce leaf size
4. replace damaged leaves

Points 1 and 3 are usually done once the basic branch structure has been grown. So this would be once a tree is 'half way complete". It is pointless to try to improve ramification in the early growing stages when the primary goals are trunk size, direction and taper. Once these objectives are achieved then you start work on the branches. Also by reducing leaf size you decrease the amount of energy available to the tree for growth - not a good idea in the early years if trying to achieve a medium to heavy trunk.

Point 2 is used when a required branch (or area) is growing weakly. By defoliating the stronger areas, you allow the weaker branches to grow stronger and hold their own. In this scenario medium to heavy reduction pruning on strong growth areas is often used in conjunction with defoliation.

Point 4 is primarily used on trees with tender leaves that are damaged by strong wind, sun burn etc. The idea is to replace the damaged leaves with a new set of leaves which will enable the tree to feed itself properly during summer and autumn thus giving it plenty of stored energy during winter (if deciduous). Before the leaves drop, the tree reabsorbs much of the nutrients from them which gives the tree a reserviour of energy to draw upon until the tree produces a new set in spring.

There are probably other reasons however this is all I can think of whilst I eat my dinner!

[alpineart]

These 3 Japanese Maple were chop tops at 4or5 years old .Very poor growing condition in the ground .When removed all but the front tree was naked , the front /middle tree had 1 shoot which was used as a leader .All have been developed purely by defoliating only These were completely stripped 4 weeks ago come Sunday

100_9218.jpg

.I thought it was 5 weeks but a i have my little bloke every 2nd weekend he was here and actually defoled 1 tree , done a better job than my wife and myself .I know it was less than a Month because i had just been released from Hospital . The taper on the middle tree has progressed better than the tree's started without a leader .

They have never been allowed to grow more than 3 sets of leaves after the first shoot had the pegs placed on them .I did place these into the ground last year to do some thread grafted root work, and the grew poorly compared to tray growing .I started with 8 tree , 3 were defoled 4 times , 3 were defoled 5 times and 2 were defoled 6 times .The second season i pushed 4 tree's to 6-7 defols and killed them the rest were defoled 4-5 times 1 died from root rot due to the lack of foliage ,it was also in a smaller pot not a tray .These 3 continue to grow extremely well.

Yes the central outer leader will extend more so than the rest of the new shoots , i simple remove it as the extend this throws the energy back to the inner growth then folow around and pinch out the rest as they extend .I haven't done these this time around as they have taken a back seat to coping with a legless lunatic hell bent on planting out as many potted plants as possible plus the Tridents , Crab Apples, Hornbeams and Cherries have taken priority .These will be hardened of over the next 2-3 days then completely defoliated again .In 4-5 weeks the same procedure will take place if the growing conditions are the same .

Buy then we should be into Summer so 1 more defol will no doubt take place mid to late January then allowed to grow on with tip pruning only .Mother nature showed me how defoliating worked .Look at a Gum tree after a bush fire , the only Gum that wont grow back is the Mountain Ash or Alpine Ash , fire actually kills it .As for Deciduous after a tornado ripped through Myrtleford back in the 90's all the tree's were ripped out of the ground or completely stripped of all their foliage Within 4-6 weeks they were all sprouting or back in leaf , my garden Maples were exactly the same.This is when i started defoliating Japanese Maples however i only did it once or twice .Note one tree still has big leaves , i have layered the same tree that produced these and i specimen continues to have large leaves after defoliating .

Cheers Alpineart