Use of Boric Acid to remove moss from trunk

I attended last weekend's Brussel's Rendezvous. One of the guest artists suggested the use of boric acid to help remove moss from tree trunks. They also suggested the usage of vinegar. My notes are not clear as to the formula (the dilution ratio) for the boric acid, although my weak brain seems to remember a 1:1 ratio of vinegar:water. My google search has been non-productive. Can anyone offer a suggestion as to the correct formulas for either of these suggestions? or alternatives beyond scraping? Thanks in advance.

hi,
any acid will kill moss - vinegar - acetic acid, works but smells, citric works too - lemon juice etc, boric i have not heard off but it will work i'm sure.

dilutions are dependant on how carefull you can be - weak solutions kill moss in 6-8 weeks and wont mark pots etc, strong acids work in 2-3 days but must not get on soil or pot - just experiment on wild moss then use on your trees

cheers Marcus

I have used a product called Simple Green. It's a green cleaning product that is safe to use on plants. Like any cleaner you need to keep as much out if the soil as you can.

Mitch

I've used a soft bristled tooth brush before on my Oaks, worked out pretty well.

logan3 wrote:I've used a soft bristled tooth brush before on my Oaks, worked out pretty well.

yes, this works well on smooth or tough bark but would ruin delicate flaky pine bark plates. Tha advantage of spraying an acid product is the lasting protection - I treated a black pine trunk in january and it is totally clear of moss - on the same tree a branch was not treated, just brushed, and the moss is showing still.

cheers Marcus

logan3 wrote:I've used a soft bristled tooth brush before on my Oaks, worked out pretty well.

My recommendation, too.

The world may revolve around chemistry, but bonsai needn't.

I am in agreement with Jim on this...I have a utilized a toothbrush for years for this purpose with good results and I am a chemist.

Regards,
Tom

I assume this will work for lichens as well? I have a lot on some of my collected trees and wonder how to properly remove them (tooth brush won't work...I tried). IF I elect to clean with vinegar or simple green, what is the best practice?

My plan is...
1. Water the plant thoroughly, saturating the soil.
2. Place a towel around the base.
3. Cover the pot with plastic including the base and the towel.
4. Clean with vinegar/simple green.
5. Wait for the vinegar/simple green to work (HOW LONG TO WAIT?)
6. Flush/wash the tree (top portion).
7. Remove plastic and towel.
8. Water/wash the tree.

Anything you would add/delete/change from these steps?

Thanks!!!

Dario
Your outline looks good to me. I use a soft tooth brush on all my trees. It works very good on boxwood. I use the spray bottle on a small area wait for a few seconds you will see the algae and moss start to come lose then use a soft tooth brush to work harder areas. Then I wipe off as much as possible. The rense off the remainder.

Mitch

Thanks Mitch. The lichens are more on the cedar elms...and there are lots of them. I pulled the ones that I can but there are various types ( can count at least 4)...some extend out, some are flat.

I have a question in return: Why do you want to remove the lichen? Lichen does not hurt the tree and adds to the sense of age (& I really don't want to hear people saying that lichen hides <shudder> bugs).

Jim,

I know they do not hurt the tree and as I posted, I am not sure yet (there is the big IF there). I know I do not want too much of it and I reduced it tremendously on some already.

My trees from Puerto Rico seem to be self cleaning though and the lichens on them reduced on its own.

How do you get moss off your cork bark and flaky bark trees ? Toothbrush doesn't seem to work so good. I agree with marcus, for certain types of bark, an acid solution works well without damaging bark, and also gives long lasting protection.

On flakey barked trees like pines and larches, you simply paint full strength vinegar on the moss and put into the sun. Takes awhile but you preserve the bark.

Thanks Fore, that was my point. I use vinegar solution on all cork bark elms and black pines. Bark stays on the tree.

Maybe Jim and Tom dont have any trees with extremely old flaky bark in which case the tooth brush is perfectly ok, but the old bark flakes are precious and must not be brushed or rubbed as a decade or two of age can be destroyed in a moment. Moss and lichen in these circumstances is bad as it grows under the plates, lifting them further away from the layers below until they fall off by themselves.

This works well Dario - cover the soil with a plastic sheet, make sure the top of the tree is bone dry, spray (or use a soft small brush) full strength white vinegar on the moss, start at top and work down. Revove sheet and place tree in full sun to dry vinegar - moss will die off over 4 or 5 weeks. dont water tree before or after the ttreatment - all you are doing is diluting it, making it work slower and with less effect. Once vinegar is dry water tree as normal, but not the trunk really

Vinegar is a weak acid so is about as safe as you can get for this job - (i personally dont think any harm comes if a little gets on the soil either) - moss can be totally killed in 6-7 days with stronger acids but you need to protect the soil, the pot and foliage so is probably best not tried until you have practiced on a real tree and observed. Using this treatment can keep moss away for a year easily.

Bonsai needs science and chemistry guys - or the trees would often be weak, sick, mouldy, mossy, bug infested and slowly rotting to compost rather than maintaining beautiful dead wood - just put every string in your bow and know when to use them.

cheers Marcus

I agree, but I think you mean put every arrow in your quiver.