pruning

[CA arborista]

Did I misunderstand something that I read?

Is it true that the only time that a tree shouldn't be pruned is when it is first pushing sap (coming out in leaf)?

When is it OK to proceed? Pushing sap is how trees get stored energy from their roots by means of transpiration, isn't it? So, at what time is it OK to prune?

Thanx

 

[kennertree]

Pruning can be done almost anytime. Just avoid pruning on oaks in the growing season when oakwilt is present. You also want to avoid heavy pruning in the spring. Trees have used alot of energy to produce foilage so the tree doesnt need to focus on healing.

 

[ATH]

Avoiding pruning during early sapflow is more aesthetic and less tree health related.

Depending on which species you are working with, you will likely get significant sap dripping out of the wounds. However, this is not enough to impact the tree's starch needs. It can just look a little ugly - especially if something (bacteria, mold, etc...) grows on sap later in the year.

Some trees will put out small sucker sprouts when pruned early spring. You do need to get those cut out within a few years, but again, not a huge concern if taken care of correctly.

Bottomline for me is to let the clients know what to expect with spring pruning. Make it clear that you are not putting them off - just letting them know what to expect. "I'll prune now, but you should know you will see sap flowing from the cuts. This doesn't bother me...However if it will bother you, why don't we wait until mid-June. You decide." I find most folks trust my expertise: "If it doesn't concern you, let's get it done, why wait."

 

[masterarbor]

i've really only noticed it in maples, and it's never seemed to be a big deal. a sugar maple will drip for some time, however.

 

[treemandan]

Pruning can be done almost anytime. Just avoid pruning on oaks in the growing season when oakwilt is present. You also want to avoid heavy pruning in the spring. Trees have used alot of energy to produce foilage so the tree doesnt need to focus on healing.

I won't really touch an nice oak or remove and grind a dead one in the heat. If I have to prune it I will only do a clearance job if needed and try to paint the cuts.
Anyone, besides me , ever see or use LAC BALSAM?

 

[treemandan]

The best time to prune? I have heard it said the best time to prune anything is when your saw is sharp.

 

[kennertree]

I won't really touch an nice oak or remove and grind a dead one in the heat. If I have to prune it I will only do a clearance job if needed and try to paint the cuts.
Anyone, besides me , ever see or use LAC BALSAM?

From what I've read it has no effect on wound closure but it does help reduce colonization of insects or fungus.

 

[masterarbor]

The best time to prune? I have heard it said the best time to prune anything is when your saw is sharp.

 

[masterarbor]

From what I've read it has no effect on wound closure but it does help recuce colonization of insects or fungus.

wound paint is an obsolete practice. do you feel that it is still effective in thwarting vectors and pathogens? it is still available to buy, but the only time i use it is to hide a boo boo.

 

[kennertree]

wound paint is an obsolete practice. do you feel that it is still effective in thwarting vectors and pathogens? it is still available to buy, but the only time i use it is to hide a boo boo.

No, I never use wound paint. I've heard of people using it just to prevent things like oak wilt. Oak wilt is not very common here in east tn. I've read that it can be helpful on large wounds to prevent pathogens from entering.

 

[tree MDS]

I won't really touch an nice oak or remove and grind a dead one in the heat. If I have to prune it I will only do a clearance job if needed and try to paint the cuts.
Anyone, besides me , ever see or use LAC BALSAM?

Yeah I had some of that, years ago I did a sub job for one of the guys that actually gives part of the oral arborist test, he said it was the only thing that they recomended for wound paint, and that they use it for grafting-oh, and also "its also good for covering up rip cuts in a pinch", that was his reason for carrying it. Go figure

 

[M.D. Vaden]

i've really only noticed it in maples, and it's never seemed to be a big deal. a sugar maple will drip for some time, however.

I frequently mention Dr. Shigo's book when customers ask me about this. The tree biology book.

He indicated to "perfect" times per year to prune as right after leaves drop and right after leaves emerge if I remember his choice of words.

And within one page's distance, he mentioned that pruning can be done throughout the year (in general).

Homeowners are amused to hear what the "perfect" world of pruning would be like to have a company come out for every species on their property and add travel time and clean-up for each type, and how expensive it would be.

Including how extremely well we would be paid for a few weeks in spring and autumn to cover our entire year income needs.

The sap dripping is interesting. I think that in one way, nothing changes. The tops need some moisture. So before a cut - say on a maple - water was moving from the trunk "POINT A" to the limb "POINT B".

After the limb is cut, the water is still moving from Point A to Point B. It's just that Point B is different. I think a week and a half is the longest I've seen a maple or birch drip.

 

[treeseer]

I avoid heavy pruning when leaves are forming or falling; i think shigo had it right on that.

re lac balsam, I would like to buy some more and try it again. big cuts with exposed heartwood should be sealed to prevent cracking. see the picture on page 28-29 here http://www.treecareindustry.org/PDFs/TCI_Mag_Feb08_web1.pdf
This tree has not been worked on for over 10 years--see any rot in that wound?
looks like lac balsam to me.

read ansi--sealants can be recommended. to be always against wound paint seems pretty dogmatic.:spam:

 

[D Mc]

I avoid heavy pruning when leaves are forming or falling; i think shigo had it right on that.

read ansi--sealants can be recommended. to be always against wound paint seems pretty dogmatic.:spam:

Re pruning timing - +1 we agree.

Re sealants - this is a big area of interest to us. You mention sealant nowadays (to other green industry professionals) and you get a face full of rhetoric, no thought. Is the very best thing we can do for a large wound on a tree nothing? This area of tree maintenance, in our opinion, warrants more research. These large wounds that crack and split can allow unnecessary advancement of pathogens and access to zones in the tree that might be able to be prevented. I have been through all phases of the tree paint controversary; from paint everything 1" and larger with a brush on the end of a pole saw to using those new fangle spray cans, and to this era where tar based paints are considered worse than Armallaria. The tree does everything in its power to seal off injuries; that should clue us on its mode of defense.

D and S Mc

 

[CA arborista]

I avoid heavy pruning when leaves are forming or falling; i think shigo had it right on that.

Aha! Treeseer - I knew that if I waited long enough you would appear! It may have been one of your comments that I remember mentioning not to prune during the Spring flush.

We have two pruning jobs that require heavy pruning. One is to balance a mature oak that had been previously pruned to accomodate residence expansion and the other to balance nearly mature trees planted too close to each other. Just looking at the oak pushing out catkins and yellow-green leaves gives me the feeling that we need to give it time. One of the other trees is a maple.

I went to treesaregood.com and they said not to prune immediately after the leaves are out because of the energy expended by the tree to establish the crown. Seems to me that by then it would be OK.

As for using a sealant - seems like a good idea to me. I've seen lots of decay at large pruning cuts on mature trees. Something to condition the wood and help the tree repair - does lac balsam do that?

 

[ATH]

I went to treesaregood.com and they said not to prune immediately after the leaves are out because of the energy expended by the tree to establish the crown. Seems to me that by then it would be OK.

Form a "tree energy" standpoint, it is better to prune before the leaves are out. They do have to use starch reserves to develop leaves.

If you prune before the leaves are out, that starch is not spent, so no energy loss.

If you prune as soon as the leaves come out, the starch is used, but the leaves haven't had time to "earn their keep" by providing sugar back to the rest of the tree.

If you prune several weeks after the leaves have come out, they at least had time to contribute something back through photosynthesis before being removed.

Most of the time, it is not a big deal, but I am pretty sure that is why they say to avoid it.

 

[Bermie]

Form a "tree energy" standpoint, it is better to prune before the leaves are out. They do have to use starch reserves to develop leaves.

If you prune before the leaves are out, that starch is not spent, so no energy loss.

If you prune as soon as the leaves come out, the starch is used, but the leaves haven't had time to "earn their keep" by providing sugar back to the rest of the tree.

If you prune several weeks after the leaves have come out, they at least had time to contribute something back through photosynthesis before being removed.

Most of the time, it is not a big deal, but I am pretty sure that is why they say to avoid it.

I agree in general with these statements...one addition I would make is that heavy formative or reconstructive pruning would be better done in the summer.
Removing large amounts of wood in the spring (before leaf break) does to some extent mean removing stored energy reserves that are located in branches, twigs and behind buds. So the tree has to find enough energy to break buds, form leaves AND grow callus and woundwood after a spring pruning.
If the reconstructive pruning is done in the summer, energy production is ticking over smoothly, not on the steep upward demand after spring leaf break....do I make sense?

As for wound sealing, I have learned that in certain parts of the US there is concern for specific pathogens that can enter fresh wounds. Again I would say in general wound sealing is unneccessary EXCEPT where there is a defined issue with a specific pathogen. We use pruning paint on citrus trees because of a virus that is rampant...not sure it actually works though.
There are so many spores and creepies floating around in the air, they have landed as soon as your cut is made...putting a sealant on top of it just seals them in nice against the wood, moist, warm....

Properly placed cuts are the best option, allow the tree to utilize its inherent sealing and compartmentalizing strategies. Pruning at the right stages of tree growth, minimizing the need for large cuts...

I have observed many large pruning cuts and storm damage on trees over here, that from outward appearance you would think must be leading to spreading rot way down into the core of the tree...not always so!
I had a large Poinciana to take down,(too bad the tree had to come down to make way for construction) usually a tree associated with rot pockets and internal decay. This one had a large (24") old wound that had not closed...soft decayed wood on the outside. When I had got it all down I dissected the area and the decay had precisely followed the branch tissue down to the origin of the bud in the trunk, a classic 'cone' shaped compartmentalized area! It also had an old cavity with concrete in it...I expected a long column of decay leading down...not so, sound wood at the base! These wounds were at least 20 years old, and the decay had not spread beyond the branch cone!
A tamarind that had suffered greatly in a hurricane five years ago, shattered ends, multiple resprouts...the dieback was minimal, the extent of decay was way less than I would have expected...callus/woundwood was strong. Trees can outfox you..amazing stuff!

Then this week, an avocado, split branch, loads of internal decay, weak points failed in high winds we had for two days...but it had never been taken care of properly...the badly placed cuts and neglected pruning needs were what led to the problems!

I will qualify the above by saying that we do not have the range of nasty tree decaying fungi and destuctive insects that you all have...so maybe we luck out in that regard!

Happy Easter all!

 

[CA arborista]

Thanx, Bermie, for your info. Yes, ideally it makes perfect sense to wait until sugar production is in full swing in the Summer. In residential tree care it's not always that easy. The customer wanted to do the cutting soon after they took the fence down - drove by today, and the fence is down. I had asked for at least an additional month. I'm hoping that the tree is advancing quickly, many oaks in our area are already fully out.

The indiginous trees in our area are Blue, Valley, and Live oak as well as Gray pine. The biggest problem we have are with Live oaks as they tend to develope with two or more co-dominate leads that include to give the illusion of one trunk. Typically, one of these leads will break off leading to the failure of the remaining leads due to the lack of buttress roots on the side that first failed. The other problem is if one lead is cut off. The supporting roots remain but the wound from the top combined with the hollow area at the base formed by the co-dominate leads joins with decay. We have been using a 1/8"x1' drill bit to test for resistance with these trees.

I had read an article about swelling in trunk wood as a sign of decay. We removed an oak with this type of swelling and disected the area. There were some area decayed but not as advanced as we had expected. What do you know about the pathology of the swellings in oak (anyone out there?). We have just picked up an account for an apartment complex that has a HIGE Valley oak with one of the trunk swells. The thing hangs over two of the units!