Cavities in Trees

Is it a good idea to fill a cavity in a tree? Follow along and come up in the tree with Blair and take a close look. I think you will learn a lot!

[@justinshelly3850]

I started watching your videos a few months ago. You have been very informative and really showed me what it means to be an arborist. You pushed my curiosity over the edge and right into a budding career as an arborist. I never knew how wonderful it feels to be 40 ft up in the air pruning others trees with a mind to do what is best for the tree until this year. I have found my calling and I just wanted to say thank you for sharing all your years of knowledge and experience in the field. Your expertise has helped this greenhorn on a job more than once. Here's to another 10 years of content! Thanks Blaire

[@arboristBlairGlenn]

When I first started my channel (15 years ago), my purpose was to have video content that was visually helpful for my clients. Over time, tree workers started commenting as well. Thanks for your kind words. Keep on keeping on😊

[@u4987]

Great video Blair, very informative as always. Thank you for sharing it.

[@thehomeplatespecial597]

Very interesting video on filling tree cavities! I just watched one at the Univ of Tennessee on youtube where foam (Great Stuff), cardboard, paint and wire fence were used. I was surprised as a lay person. I had forgotten cement and even bricks and morter were used in the past. I immediately thought to ask you about the foam and your video was already queued by youtube.

[@General_reader]

The Home Plate Special saw the same video. They seemed to be saying the opposite as Blair. Would like to hear a response from him...

[@thatguythatdoesstuff7448]

The application of what UofT did is completely different than what you see here. Many of the the wounds on this branch were too large for the size of the branch to consider filling with foam. Second, many of the wounds were exposed in way (skyward, or exposed to runoff) that water is definitely going to get in. Branches themselves are not candidates for foam filling in the same way as that trunk of the sugar maple in that video. That branch probably should have been removed ages ago.

[@jasonsejkora4578]

I also saw that video. I have a cavity that's coming practically straight down into the main log of a 100-year-old plus oak. I'm super tempted to fill it with foam and shoot it with that aerosol tree paint to cover it and seal the wound it was created while the limiting it this spring. I'm going to take a ladder and go look at the cavity it's been a month since I was up there last. I painted it when I was in the tree but I haven't been up to take a second look since. 👀

[@timfowler4642]

Good info but please post video of what you trimmed off and what it looked like afterwards.

[@arboristBlairGlenn]

Sorry about the shaky camera, I'll do better

[@rln970]

Did you do a follow-up on this tree? It would be interesting to see the decay progression in the affected limbs.

[@poppys3728]

I know this is an old video, but the sound track was distracting.

[@arboristBlairGlenn]

Agreed

[@outonalimbtreesvc]

Symptoms of cavities can often be misleading- To the trained eye, there are signs that are evident, they scream that there are internal problems. Convincing a client that these problems warrant further investigative work, can often be quite difficult, because of the old saying " I will believe it when I see it". Unfortunately, often we have found the reverse is true- "I will see it when I believe it". I use books & pamphlets to show similar examples- Great Video Blair-

[@General_reader]

You say adamantly that foam is bad. But what do you do with the cavities after removing said old foam?

[@General_reader]

Have a void at the trunk base of a 100+ yr. Old oak. About 1/3 of the way through the trunk. I want to fill in order to keep animals from burrowing in, making the problem worse... Not to mention it's a real eye sore on such a beautiful thriving tree. Any suggestions? Thanks in advance.

[@arboristBlairGlenn]

Identifying Hazardous Trees This is really an area that needs to be done by an expert but there are many signs that indicate a problem or potential problem. It is important to understand that different types of trees have different characteristics and problems unique to the variety. That said, I will give some general advice that are “red flags” to a potential problem. Cracks in the limbs This sounds pretty basic but I am amazed at how few people really look closely at their trees. It is often obvious when a limb is splitting open but not always. Small cracks in main crotches can sometimes ooze water or pitch (sap).This can happen suddenly or take some time to develop. If you see cracks or openings, call an Arborist immediately. That may be the only warning you get. Cracking noise I have heard and been told by people that they heard a loud crack, but could not see anything. Sometimes the crack is on top of an upper canopy crotch or running along a large horizontal limb. Don’t ignore this obvious clue. Change in tree trunk angle Many times in my career, clients have called me to say “it seems like the tree is leaning more than it was before”. Sometimes it is a persons fear or imagination but many times there was a weakness underground that caused a change. The large Stone Pine in Blaney Plaza was saved because a city worker noticed a change in angle. Sure enough, when we looked close, the whole root ball was coming up and this huge tree was on the verge of going over. Sometimes cracks in the soil are a good indicator of movement. Also look for a separation in the soil line around the base of the trunk. In rainy weather, the soil becomes muddy and these clues are often harder to read. Drooping limbs Do some branches seem lower than they did a few weeks ago? Is there a dramatic difference in the way a tree looks? There is a situation that is very common during hot weather called “summer limb drop”. A drying out of the limbs can cause a sudden limb failure, even on a windless day! Some of the species that this happens to include; Monterey Pines, Italian Stone Pines, Valley Oaks, Eucalyptus species, and large Ash. This can happen on other varieties of trees as well but these are the most common in the Bay Area. (Correct me if you think of others and I will list it as well). Mushrooms at tree base Some types of wood decaying organisms will push up fruiting bodies or mushrooms. It is not the actual mushroom that is the problem but what causes the mushroom. Rotting roots or trunks cannot always be identified at a glance. There are techniques that help us to determine the extent of the decay and likelihood of total tree failure and this inspection needs to be left to an expert. However, if you see these clues, get help before it is too late. Fungal bodies on trunk Just like the ground mushrooms, there are many types of growths that indicate decay.If you see anything unusual on the trunk of the tree, other than moss or lichen, then it is a good idea to get it inspected. It may not be a big problem or it might just be the flag to a bigger problem. Black balls on the trunk and limbs that look like charcoal are a big indicator to a possible disaster. Get the tree checked out! Girdled roots This is a tough one to identify as a problem but sometimes there are surface signs to girdled roots. When roots twist around each other they can sometimes cut off normal root development. If a tree was in the pot too long, then the roots can grow in a circle, rather than spreading out. Sometimes you can recognize a girdled tree by a lack of a root flair. If the trunk seems to indent at the ground, that may be a clue to girdled roots. Canary Island Pines are one type of a very fast growing tree that we see failing from having lived in a pot too long. The fast growth on top can exceed the root development and a girdled root ball can cause the tree to snap off at the ground. There are many other signs of potential problems such as hollow trunks, cavities, past trunk damage, insect activity, improper past tree work, etc., but these are really areas that you would be guessing at. The main point that I am trying to make is that if you notice anything that worries you then you should get the tree checked out.

[@Quadflash]

(grin) A bee suit would be fine addition to the tool set. Working around the various tree-loving Vespids is a painful chore!

[@TokinWhiteKid]

Hi Blair, to prevent mosquitos from breeding in standing water in a cavity, would it be okay to staple some window screening around the opening to prevent insects from getting in and out? It would still allow for inspection and airflow plus it would be relatively indivisible. Also, would BT dunks be okay to place in the cavities to prevent mosquitos larva from developing?

[@arboristBlairGlenn]

Geoff Melle yes, that is a very good idea

[@Jamestreeman]

very good vid.

[@glumGlumm]

interesting video. I'm learning more here than watching tv

[@mooosestang]

You'd think we'd have a solution for this problem. Some sort of tar seems like a good way to displace water. I've got a great big oak with multiple large shoots coming off it in every direction and as a result it has started to rot in the middle from standing water. eventually one of those large branches is going to break off and take out my roof. I noticed it years ago, but there wasn't any solution that i could find. Being in florida it rains all the time so it's constantly filling up and drying out.

[@arboristBlairGlenn]

Tree sealant, also known as wound dressing or pruning sealant, is a substance that is applied to the exposed surface of a tree wound intended to protect the tree from decay and infection. The idea is that by sealing the wound, moisture and other contaminants are kept out, which hopefully might help to prevent decay. However, research has shown that sealing wounds with tree sealant is not necessary, and in some cases, it can actually do more harm than good. For example, in certain species of trees, such as oaks and elms maples and birch, sealing a wound can trap moisture and create a favorable environment for decay-causing fungi. In general, the best approach to preventing decay in trees is to promote overall tree health through proper pruning, watering, and mulching practices, and to avoid damaging the tree in the first place. If a tree does sustain a wound, it is best to simply clean the wound and allow it to heal naturally, without the use of sealant.

[@Craigdna]

I knew someone that on smaller trees, they would bleach wounds/cavities, and then apply tar to seal it. This seemed to work and I was curious as to what your thoughts are on this.

[@arboristBlairGlenn]

Evidence does not concur with this concept. Dr Alex Shigo has debunked this very old process as having no beneficial value.

[@rcatyvr]

Would you scrape out the damaged/rotting/infected wood in a cavity--sort of tree debridement? You mentioned that most fillers allow water to infiltrate. What about waterproof compounds like the plastic in glue guns, or layered applications of tar? Either of those perhaps in conjunction with a hard object like a shaped concrete plug imbedded in the waterproof substance to add some more strength. What I am envisioning for a large wound(s) on a tree otherwise worth saving, is debridement followed by tar painted/sprayed into evey crevice of the wound to perhaps 1/2 - 1" thickness. Then filling the cavity to 95% with rebar concrete. When the concrete is dry, topping off with a final layer of tar and embedding a brass plaque with the dimentions of the cavity engraved on it. What do you think?

[@arboristBlairGlenn]

Richard Campbell -Richard, if you study the works of Dr Alex Shigo, you will understand that all the efforts to do what logically seems right, is actually making things worse. Decay doesn’t stop because the dead tissue becomes a growth of mycelium that goes deep into the tissue. Covering up a wound just hides the problem and you can no longer inspect it. Kind of like putting a bandaid over gangrene.

[@matthewblackwood4704]

She likes it when you bottom it out

[@yamahapeanut44]

Try not to kill honey bees if possible. They are easy to give away to someone who wants them. People will come remove them with little harm to the swarm. Honey bees are having a hard time in america. Yellow jackets are another story. Though in Alabama yellow jackets build hives in soil.

[@macalex3]

I see everywhere dont fill the cavities but I don't see what to actually do. I have a cavity in a tree where I can have 4 inches of water, I expect this moist environnement brings the insects and hurt my tree. I was thinking of not only treat it but fill it with foam. I don't think leaving it as is is the solution. Any suggestion?

[@arboristBlairGlenn]

The short answer is leave it be. The why is the long answer.

[@Thatsmessedupman]

Do what do you do to keep the water out if you can not foam or cement?

[@magkyt3636]

Nothing worse than pissed off bees. lol

[@rickreid15]

The material covering the foam kinda looks and sounds like fiberglass resin to me.

[@readysetsleep]

Most likely automobile body filler, they use to recommend covering the foam with it so it looks aesthetically pleasing from the ground. This video from 1997 talks mentions the technique kzbin.info/www/bejne/iGeUnql9nK2Dh80

[@Tryinglittleleg]

I hope the hard, concrete-like covering wasn't asbestos!

[@Patty-qd1lz]

I have Carpenter ants in my swamp maple, which is 43yrs. old, and my bug guy told me to leave them in there. He said better to be in tree then to walk over and into your house!! What do you think?

[@ydwtfwm9920]

Can you tell me a black ash, I'm in Northern CA, filled with cement that is now collapsing is likely to split and fall. I know the common sense answer, I just need a little back up to save someone's home, car and maybe life. Thank you for the educational and experience based videos.

[@arboristBlairGlenn]

I would be nuts to advise without seeing it

[@vitoamos2815]

grow a plant in it !

[@pozzee2809]

Just get to how to fill/protect cavities!!

[@arboristBlairGlenn]

I guess You really didn’t understand this video at all. The point is, don’t fill. Dr Alex Shigo did an extensive study and it is accepted in our industry that it is better to leave them alone. In other words, you can’t fix decay.

[@julianalderson6996]

bro i rekon its gota go, mainly cos where it is"

[@5herwood]

Check out some Charles Addams here: www.invaluable.com/auction-lot/charles-addams-1912-1988-gag-cartoon-new-yorker-61-c-7eilpswrab The caption is something like "Did they ever find out what happened to Mr. McSwain? "

[@danieloneil2012]

Just from the looks of this tree your recommendation is that you cut it down this is not a beautiful tree this is a tree that the wicked witch of the east might own and keep around but other than that it should be cut down just from the foliage alone it’s outlived its life

[@5herwood]

The foam looks like diseased flesh.

[@jimk5307]

Meanwhile in Tennessee... kzbin.info/www/bejne/m5e2Z2iMht53kNk Happily using foam in 2016.

[@dekonfrost7]

You are wrong about foam if capped

[@arboristBlairGlenn]

And your source is? Not wrong

[@dekonfrost7]

You aren’t an arborist, you are a guy with a chainsaw.

[@arboristBlairGlenn]

Serious insult. I have been an ISA Certified Arborist for 31 years. I have studied under many well recognized Arborists.

[@murphy4trees]

taking that entire limb off was such a bad idea.. about the worst thing you could have done. Even if you left a 2 or 3 foot stub, the tree would be better able to compartmentalize... I disagree with so many of your practices.. you make it sound all nice like you know what you're talking about, but you are way off in many area of arboriculture

[@arboristBlairGlenn]

Sounds like we need to talk trees then. I’m always open for other opinions. Leaving a two foot stub might be a better way to minimize future potential for trunk decay. However, in all my years of study, and listening to Dr Alex Shigo, the consensus as I have heard it is to maintain the branch collar and not compromise any of the four walls of protection. Now when decay is involved, before your decisions, that decay column inside may have already spread too far. Most of the big oaks I work on are full of old decay pockets. Most have been compromised from construction damage. So, Murphy, tell me in more detail about why I’m “way off”.