Like JinMa said the higher gloss paints are less gas permeable.
The same goes for outdoor wood paint. The higher gloss paints have more binders. Those binders give it a gloss effect. But also have the largest effect on water and gas permeability. So higher gloss paints tend to be more weather proof (all else being equal)
Mud, clay, lime etc are quite breathable. Interior latex is also quite breathable.
The special versions for walls you want to clean (kitchen, staircase halway/ spots where people touch the wal with dirty hands etc)
Have more binder. So you can scrub them with water, without scrubbing of the paint. This also makes em less breathable.
If the less breathable paint becomes a problem probably depends on many factors. Diluting it thinner might help. brand etc might make a difference. Probably tree age/species matters to.
Just safest easiest and usualy cheapest to use the flat or lime based interior latex. (cheaper is usualy better, since they use more lime. Since lime is so cheap)
Glidden gripper undiluted has worked fine for me…but I don’t have the time/desire to mix with water (or drywall compound like John at Fedco), so I just slap it on. I doubt it has to be an exact science especially if a thicker paste made by mixing with drywall compound is acceptable. We just touch up when/where needed but it’s not often.
if painted a few trees i topworked. to avoid sunburn.
if been/spoken to someone, who paints their trunks who told me he did that to avoid winter damage. (the sun could heat 1 side of the trunk, the difference in temperature in winter would crack the wood according to him)
if done that myself on my own tree’s a few years ago. Did not bother the next year, and haven’t noticed a difference.
If painted a bunch of dubble grafted interstems last year. Not for sunburn reasons, but because i was planting them out in a heatwave. And was curious if the paint would make a difference in % of take. In the end i saw no significant difference in the just parafilm and parafilm + interior paint group. Although admitently it was a small sample group. (20 ish)
I had a small “feeling” the less light from the paint gave me a little more callous on those i “checked on” could have been coincidence, and it was callous outside so probably did not contrubute to the graft taking)
I do have less experiance than some/most around here. Since im still reletivly new to fruit tree growing.
This means that virtually everything if done. I first searched on the internet. If not been growing tree’s pre internet age. Im not sure, but i think i wasen’t born till after the internet.
Although i have not run a comparison on high glos vs glos vs flat paints. I thought the mechanisem (increased amount of low gas permeability binder for more gloss) was something worthwhile to add.
If i have 0% practical experiance (ie never done it myself) i mention that in my reply
when in doubt always feel free to ask me for proof/explenation or more information
I’ve noticed that you are very good at searching for info from the internet and summarize your research in a concise manner. That is skillful.
It would be nice to let readers know where you get your info from (your sources) as some people may want to look into it further. Also, as you know, many sources on the internet is questionable. Some experienced growers here may be able to point that out if necessary.
Not everyone like to do research. You have done a good job in helping members here. Like any good research, citing sources and give credit where credit is due is a nice thing to do.
Hard to cite sources from memory
Most of my reply’s are from memory, and unles i mention “i don’t have any experiance” in it. I have actualy done the things.
I do however usualy first research and look up information. Until i think i understand the underlying mechanisem. With a lot of things there is no “1 way that always works” it’s usualy determining which way works best in what specific situation. “Understanding” the underlying mechanisem helps a lot with this.
Than i “practise” and do the things myself.
Explaining underlying mechanisem even though i have experiance.
I belive however just saying “i did this, and it seemed to work” is not always that helpful. And can somtimes give people low sucses. Since their situation might differ vastly from yours. So even though it worked for “me”, it is no garantee that it would work for some-one else.
To me this could be summerised by “sharing experiance vs sharing knowladge”
you seem to suggest (although i could mis-interprete) that when i see a question, i start googeling and then type a respone. Without having any real world experiance. This is simply not the case.
Im not just researching other peoples questions.
I did however had a lot of the same questions over the past years. Looked for information and “awnsers” and started experimenting.
Citing sources and giving credit
When i can easily find a source or if i had to look it up to be sure if i remembered corectly i post that source in my reply.
Some are hard to find back though. And typing a reply “explaining” the underlying mechanisem already takes a lot of time. Looking up all “origional” sources. Than checking if your giving credit to all the right people (and not just people who got the information from some-one else) becomes incredibly tedious and takes a long time.
It’s a forum, not a scientific journal
I think you should expect people to cite all sources and credits in a post in the guides or reference section of the forum.
But your expecting to much from people to do all that extra work for a reply on a forum.
In the end this is a forum, not a scientific journal. The person asking the question should have some responsibility to verify or compare advise. Or take the risk and “trust” it, and see what happens.
I have even written a topic, trying to help people to find information themselfs. Or to help them find information to verify if given advise is “good”
Accuracy of information on the internet.
You make a verry good point, not all things on the internet are true. And it is hard to judge the accuracy of somthing without seeing the source that origionaly listed the information.
I have writte a reply in another topic about this here.
In the end the forum works in part due to multiple people “checking” others advise. And speaking up if they disagree or adding their own contribution.
That’s great research, now go back and find out how permeability affects the health of a tree in regards to painting trunks. It stands to reason that you want a tree to be able to have wounds dry out, but I’m pretty sure that the point of suberin is to reduce permeablity.
From wiki, “Suberin is found in the phellem layer of the periderm (or cork). This is outermost layer of the bark. The cells in this layer are dead and abundant in suberin, preventing water loss from the tissues below.”
The leaves certainly need access to the atmosphere, but it seems that trunks may be OK without it. Otherwise university guidelines probably would be more specific about what paint to use given how often it is used by commercial growers in southern areas to prevent sunburn.
My hunch is that If trunks are young and green they have chlorophyll and may benefit from permeability. The chlorophyll has to be serving a purpose and it can’t function without gas exchange.
I also notice that water non pearmeable but gas permeable grafting tape (like parafilm M), leaves the bark nice. But non gas pearmeably tape can leave bark black and discoloured. Tree’s seem to be fine. but the black bark worries me. If this would also happen with really old bark, i have no idea.
You could experiment and paint the whole trunk with a high glos outdoor paint. But im not willing to risk a whole mature tree to find out if the more expensive paint is oky to use. Ill just stick to the low binder cheap stuff.
Come on, either give me some science or anecdote here. Graft wood is very young and tends to have chlorophyll and therefore stomates. It has no corked bark as older trees do. Chlorophyll dies when deprived either oxygen or light. A tree naturally kills it off as it ages, apparently.
Incidentally paint quickly cracks as soon as trees being to grow, I doubt the smothering affect even lasts for more than a brief time- but I’m just running on imagination here. I don’t think latex paint has much stretch after it dries though.
" The whole tree: branch, stem and roots have specialized groups of cells called lenticels which open the normally impermeable bark and allow O2 to enter and CO2 to exit. The lenticels are attached to ray cells that penetrate deep into the wood. "
That’s a good question, Alan. Honest answer, I dunno! It would be interesting to see exactly how impermeable bark is and how much painting the trunk would affect that, especially considering that you’re probably not getting the same level of coverage painting a tree that you would painting a prepped-and-primered wall.
All that aside, though, flat paint is the cheapest, so if it does the job maybe that’s reason enough?
Yes, I know, but the question is what damage is done if a 2 or 3 ft length of trunk has it’s permeability limited by paint. How long does that limit last once the tree is growing and the trunk is expanding.
Of course. This discussion is academic for me and I don’t think we are talking about anything with meaningful consequences. However a little civil debate is always educational.
i don’t think anyone tried to find an awnser to that question. Since the paint that might damage the trunk is more expensive. And there seems no be no reason to suggest that the more expensive paint has advantages over the cheap one. There might be disadvantages.
This ofcourse is not proof it will not work. But i think there is no awnser to your question. Although at least not a scientificaly vigerously researched one.
Compare it to the question.
Will M26 apples taste better or grow bigger if M26 is grafted to MM111?
Might be, dunno. Don’t think anyone ever had a good reason to justify the expense to reasearch it. Since there seems to be nothing to gain by knowing the awnser. Or at least the anwser does not seem to be worth the hassle.
I would swap the question to you Alan.
Prove that gas impearmeable paint is better, than the “cheap” stuff.
Why would it be “better” ?
How would it “help” the tree. Scientific sources only?
I never suggested glossier paint would be better and I’m not really trying to be the person with the right answer. I run a nursery, manage orchards and have made my living in the dirt for 50 years so I don’t have much to prove.
However, often the cheapest paint is one that has been returned by a customer or something left around in the garage or basement from a paint job where there was some leftover.
My approach is to use the cheapest methods and least labor possible to get more or less the same results- I’m not much of a businessman, but that philosophy has helped me do what I like for a living my entire adult life.
This is hobby time for me and a discussion to help me and others understand the botany of trees better. Also gymnastics for my aging brain.
ah, alan that makes sense. Please let us know if you ever test out some old batch of returned paint that is gloss/high gloss. Im curious about the results to
Alex, what spurred you to use a lime based product vs a “paint based approach”? As the discussion after your post has revealed, it seems that the “rest of the world” generally does not use paint but uses a product like you chose…
So if that’s the case, then I pose the question to @oscar, @alan and others, “if it ain’t broke, why fix it?” As alan mentioned, sometimes the cheapest paint is the one left over from another project (this will be the case for me as well). I also have joint compound left over that will certainly end up drying out and not working properly by the time I would use it for its intended purpose, so I’ll probably try mixing it with some paint. However if you can make a mix that works out of lime (would pulverized lime work with water? A 50 lb bag is $3.49 at tractor supply) and maybe mix that with joint compound, would that be a better solution?
Sure it probably won’t stay on the tree as long as paint, but given the discussion about trunk expansion and the need for bark to breath (to what extent we clearly don’t know), does paint create an impermeable barrier either, and does it matter if it has tiny cracks? Probably not, but I am only speculating.
I am also wondering if the intent to paint is “varmint discouraging”, would a lime mixture be more of a deterrent, and shouldn’t it be just as easy to mix in spicy, rotten egg, or bitter materials to discourage critter munching vs paint?
I have a lot of questions and no answers because I have yet to paint a tree myself, but I’m enjoying the discussion.
Edit: regarding high gloss: wouldn’t mixing a higher ratio of joint compound reduce the “sheen factor” pretty drastically and also allow more gas transfer?
this is exactly my argument. Most people use the cheapest interior wall paint. Which contains
-mostly lime (cheapest filler and whithe pigment, cheaper paints usualy contain more lime)
-some titanium oxide (as a whithe pigment next to the white lime for better coverage, is more expensive)
-some resin to make the paint “stick” (resin again is expensive. so cheaper paints tend to have less of lower quality)
you could also just use lime. (never done it myself, read on why)
But lime is verry caustic. And thus easy to use in an unsafe way. If you can handle lime profesionaly and don’t mind the hassle of PE and how you’d need to use it. It might be the cheapest option. Due to the lack of binder i would expect to have to apply it more often though.
Yeah, we pretty much do because thousands of trees are painted this way in commercial orchards by their keepers, many of whom certainly were able to compare results.
People should relax about having to treat their their trees in the perfect way, IMO. Drives you as crazy as trying to raise your kids that way
The things that usually really matter are for the roots to get adequate air, water and N and that the pH is reasonably adjusted in extreme soils. That and pest control.
i am confused Alan. are you saying thousands of tree’s are painted with outdoor high gloss or high binder paint? or are you saying thousands are painted with lime or lime based flat paints?
