Pruning below freezing

[Stumper]

There are references all over the place about the dangers of pruning fruit trees when the temps are sub-freezing. Is there any SCIENTIFIC literature about the subject? I run into the unsubstanciated claims everywhere. Most of the local growers have read this stuff so I try to accommodate them and stay home till the temps are above freezing. My personal observations don't substantiate the "common knowledge" but since I seldom prune fruit trees when temps are below freezing.......... I'd like to have some documentation. if there is evidence that below 32 is a serious risk then fine BUT if there is no science or,even better, there is science that explains that cold matters but not till x degrees below zero it would help my scheduling.

 

[rborist1]

:Eye:

 

[Stumper]

We have relatively few days when temps don't get above freezing.(today is one). But when it takes till 10-11 a.m. to get above freezing and drops back below at 3:45 it makes for awfully short days.:rolleyes I'm confident that no great harm occurs from making cuts when the temperature is below freezing or from temps dropping a little below shortly after the cut being made I just need some ammo for reeducating some of my clients. For now I'm just telling them that the subject is debatable but I'll respect their wishes. I'm subtly reeducating some about proper pruning in general-I'd like to reeducate about temperature too.

 

[FBerkel]

Schtump,

What references? Has my Anheusers disease advanced to the point where I missed them all?

 

[Jumper]

I have helped prune many fruit trees when the temps is below freezing, and in fact you see a lot of "help wanted" ads for pruners at this time of year throughout the winter.

 

[rborist1]

:Eye:

 

[Stumper]

Sites like these :
http://www.extension.umn.edu/extensionnews/2002/PruneFruitTrees.html

http://aggie-horticulture.tamu.edu/plantanswers/fruit/pruning.html

http://www.nwnews.com/wwissues/v20n14/home2.html

http://eesc.orst.edu/agcomwebfile/garden/Fruit/prunetrees.html


There isn't a problem with people not understanding the benefits of winter pruning. The "problem" is that "common knowledge" in this area is that pruning when temps are below freezing is bad. A cursory search for info supports that belief. -Not because it is specifically stated but because of the constant warnings about "when danger of extreme cold has passed".

 

[SilverBlue]

Hi Shtump,I think that this question would be better asked to Dr. Shigo.
Try doing a search with his name included.

 

[Stumper]

Sb, That was a good suggestion but unfortunately it didn't net me anything pertinent. Please join the search!

 

[FBerkel]

Stumper,

I appreciate the references. I do get a little skeptical when I read stuff from extension services, especially when they don't list their sources. Alot of what you find is the same old stuff that's been repeated by everyone and his brother for 50 years, and no one knows where it came from originally. This is not to say that I doubt the validity of what you're saying; I just want to know where it came from in the first place. Also, what is the specific danger of pruning in early winter: dieback, disease?

We almost always wait until late Winter on Apples, but for the reason that they don't show their fireblight cankers well until then. Also, any dieback that has occured has defined itself by then.

Thanks.

 

[Stumper]

Fred, I agree about extension service advice-some of it is patently wrong. LOTS of it is old-maybe old but true, maybe old incomplete science, maybe just old wives tales!
I too am very skeptical. I can see no reason for the advice . I have found references to drying and freeze damage being the reason for waiting until just before budbreak ,but the references are actually speculation about why the old advice might be important. Sunscald is also given as a reason for late pruning but that one is pretty lame-sort of "if you are going to perform detrimental pruning, wait." My own experience does not support the late winter reasoning. -Good pruning gives good results without regard to when it is done. My quest is for some science (one way or the other) so I can get some early winter go aheads instead of trying to cram 3 months worth of work into 3 weeks in March. (Or, if the science supports it, so that I can resign myself to March Madness.)

 

[FBerkel]

Stump,

I can relate to the late season panic. We've had good success doing certain species early in Winter, especially Silver Maple and C-wood, which "show" early. No problems with the sunscald, (except on my bald spot).

 

[M.D. Vaden]

Even if there was research, I'd still do it. I've pruned to 18 degrees here and never seen damage. Had a chance to follow up on most of my projects for 2 to 15 years and all looks good.

If it was considered a bit of a no-no, it may still need to be done.

For example, another recommendation is that tree climbing projects should have at least one ground man that knows aerial rescue...

...Great rule for large established tree companies!

Now how on earth would 90% of you have started in business?

How did the big tree services start in business?

About the only way that could get pulled off is with a partnership. But most tree service people have enough work getting projects for one lead person.

 

[FBerkel]

M.D.

I guess it depends on your market, but I've always gone with 2-climber crews. You pay the extra climber, what, 35% more than you would a groundman? Even if he spends the whole time on the ground, which is usually not the case, what seasoned climber is not worth that difference in pay on the ground? Work ethic, smarts, experience, mechanical aptitude, physical conditioning, loyalty--these add up.

But I'm with you on the pruning/freezing question. I'd like to see the research.

 

[M.D. Vaden]

The extra climber idea is a good concept.

Can you apply that, if for instance, you moved tomorrow to Boise, Idaho, or Helena, Montana?

Starting from scratch that is - with customer number one?

Would you advertise for your first residential pruning, and hire a local climber you just met?

How is the second day of new business handled?

Do you think the two climber crew idea would keep people from changing regions as a business owner?

Have you heard of partnerships starting up this way?

I know of one partnership near here, but I'm not sure if it started from ground-zero - one customer on a first day.

 

[wiley_p]

I have only obeyed that rule when the tree is hardening off and when the sap is starting to run. I prune frozen tissue in the winter and havent knoticed any problems, so far anyway.