Moss Mystery

I am relatively new to the art of Bonsai and have recently been given an incredible collection of trees. That being said, unlike my trees, these came complete with beautiful moss coverings. I have been doing some extensive reading about Bonsai and have discovered through that process that the moss needs to be removed in preparation for the winter dormant season. If that is true, is that for the health of the tree or to preserve the moss for the following spring/summer? If it needs to be removed how does one go about it without causing damage to the tree?
None of the trees in my small collection had a moss covering.
I am eager to learn and would be very appreciate of any help you might care to render up!
Gaylene

Hello Gaylene. My trees don't generally have moss on the soil surface, unless I am exhibiting. There are 2 reasons for this. 1, I like to see the soil to gauge the moisture and 2, the Blackbirds in my garden are rather fond of the stuff, and pull it all out at any opportunity. Moss will not harm your trees but during the winter, the moss can hold a lot of water. Roots that sit too wet, can develop problems. If you intend to keep your trees in a conservatory, greenhouse or covered area, during the Winter, then you will be able to control the moisture a lot better and the moss is less of a problem. Saying that, it is still more difficult to tell how wet the soil is, with the moss left on.

I must add that we have very wet Winters in the UK and all my trees are out in all weathers. If your Winters are mild and dry, then the moss will help retain moisture. I hope this has helped.

Moss can be a sign that the trees are too wet. The bonsai soil I use drains so well that I don't get moss on it.
Many growers believe that the conditions that promote grow of moss are not good for trees. In Japan moss is applied before shows only.

Much more of a problem indicative of bad drainage is of course liverwort, I have had no problems with the moss on the surface of my soil.

O f course liverwort can be used effectively as an accent especially when in flower.
But never in the pot with trees.


This is 'Island in the sun', with the liverwort looking like waving palm trees. The island is a pot by John Pitt.

Never thought I'd see Liverwort used in a planting and so effectively too. Well done Dave. The pot looks a little like shortcrust pastry....quite peckish now.

Great use of that moss Dave

I use mosses in the pots of some of my Shohin, to keep them from drying out too fast. On the specimens that like a faster drainage and dislike steady moist soil, I either avoid mosses in the soil totally or limits it.
I have newer had a problem controlling that. The main reason that you don't see mosses in the bonsai pots in Japan besides when the trees are exhibited, are the same reasons and because it will not grow well in the Japanese soil mixes - plus the heat dries it out rapidly making it unable to grow well in many soil mixtures.

The advantage of having fine mosses steady in the pots, is that it adds some age to the trees when it grows controlled and limited at parts of the trunks.
I know most people cleans it off, but it adds an aging and appealing expression that also is sought fore by some Japanese bonsai artists at certain bonsai (often Pines I have observed) when it harmonises with the tree. Others removes it and cleans the trunk like on Junipers. I prefer the aged bark, also on Junipers and mosses that apply an aged expression.

Here a few examples from late Saburo Kato garden, Mansei-en, that shows successful growing of mosses in the pots and at the lower trunk parts of Pines and a Spruce.

Regards
Morten Albek

Hello Morton. The first 2 pics you posted seem to show Lichens, not mosses. Lichens are a good sign that the air is fairly clean and trees arent over watered. They don't hold water like moss does either. The 3rd shows a raised planting where it is important to have mos to stop soil erosion. That type of planting dries out quicker too.

Sorry. That's my English that doesn't manage that. I called it all mosses, but now I know a new word. I am aware of the difference in water keeping between the different types. It was also more to show that a great effect can be achieved by not cleaning of mosses or Lichens
The mosses that requires moist conditions are difficult to grow in Japan in the soil mixes used and because of the heat. Lichens cope that far better.
Thanks for clarifying the Lichens part too Will.

Best regards
Morten

Gaylene,

I am just "up the road" in Klamath Falls, so I have some experience with our unique and problematic climate.

To keep the moss you would likely have to water several times a day during the dry and heat of summer, much to the trees detriment. I imagine that with a watering regimen that is aimed at the health of the tree, the moss will simply fade away. Regardless, I wouldn't worry about removing the moss at this time, If anything I might feel it would provide some insulation and frost protection.

I find myself more concerned regarding where these bonsai originated. If they are local, then they are acclimated to your climate. If they came from somewhere else, I would take care to baby them and make sure they are in a sheltered location this winter. I have to be careful when buying stock from other areas due to our late and early frosts, and generally dry climate.

I've assumed your mean "outdoor" bonsai in this response, so if they are not, that is a different matter!

I agree with Morten that surface mosses tend to add age to a tree's image.
I never allow the mosses to extend up the trunks of the trees and always use a tooth brush to clean it off when it forms.

As to regards mosses on the surface for exhibition, a judge in the UK once told me he actively marked down trees which had moss placed on the surface? I just hope he never goes to Italy to judge

Thank you for all of the great information! The trees were indeed local - they were raised just up the Interstate in Yreaka. Mt. Shasta is prone to cold wet winters; however, I will be moving my trees to a sheltered environment to prevent damage. After reading all of your great information, I have drawn the conclusion that the moss will not damage my trees if not removed and may prevent damage during the cold season. The chop sticks are a great idea for checking soil moisture. They were raised on a drip system twice per day, and I have been concerned with the amount of rain we received this past weekend. All of the pictures posted were amazing! I am greatful for all of you for sharing your knowledge!

As to regards mosses on the surface for exhibition, a judge in the UKonce told me he actively marked down trees which had moss placed on thesurface?

When preparing for a show, moss is placed in the pot 6-8 weeks before the show to let it "grow into" the soil and look natural. I would score down moss that had just be plopped down on the pot, too.

Gaylene, the one thing you do NOT want moss to do is grow up the sides of the tree. It can ruin/rot the bark on some species. So use a soft toothbrush and get rid of all moss growing ON the trunk.

I personally remove the moss before early winter especially if applying a lime sulphur wash for those
wee beasties,I always apply fresh when showing but only around and in between the surface
roots to emphasise them NEVER! the whole surface of the pot, with regard the moss holding water
using the right moss would eliminate most of that problem, we have all seen it! dollops of pompom
moss as thick as axminster carpet thrown on to the surface basically acting like sponges I,ve
spent hours out searching for that almost green baize type moss or any of the really fine variety,the japanese
dry there moss out then sprinkle it around the nebari when repotting. hope this helps!.

regards Alex e