Trying to identify type of moss/other substance

Hi everyone. My eastern white pine has had this grassy/mossy looking substance growing on it for years and it seems to be very hard to get rid of.

I don’t really think that it’s moss because when I pull it off, there are deep roots attached.

I’ve tried pulling them all out and it always seems to come back with time.

Does anyone know:

  1. what this substance is? Species?
  2. how to get rid of it without harming the tree?

Here’s a photo.


Birdeye pearlwort maybe? Can you check out photos online and see if maybe that fits?

That actually does look quite a bit like it.

Have you ever had experience with this stuff? It definitely feels invasive and aggressive.

There’s probably a variety of stuff online that I can check out for getting rid of it, but it likely won’t be specific to bonsai, and I’m not sure if it makes a difference.

My main concern is that it’s so close to the root system that I don’t want to hurt the tree. It was just repotted this year as well.

Thanks for the help!

Unfortunately, I don’t. I just used a plant app to find the most likely candidate. Ryan has discussed weeds in the pot before. I believe he recommended brushing vinegar on them or cutting them to the surface and to continue cutting every time a shoot tries to pop up so that it uses up all of its sugar storage and dies back.

Ah ok, cool, I’ll see if there’s still any video for that in the library. But that should help nonetheless.

Thank you again for the help!

It seem to be a sort of Irish moss. This is not an actual moss as the name intends, its simply a ground covering switch spreads like a weed.

When removing weeds from pots I have the best success by removing just after a large rain or watering. This seems to looses the soil a bit compared to dry substrate. I use a chopstick or tweezers and pull the plant up with my fingers while leveraging the weeds out.


looks like Irish moss to me. I hate it. Im always ripping it out of bonsai pots and its all over my garden. Highly invasive, hard to control and its sold at all my local nurseries. Theres even a bonsai shop in town who purposefully adds this to his moss. Yuk


The best way I control it is just to be vigilant. Irish moss pops up it green bastard head before my desired moss making it easier to remove. If you dont get the root, it will be back. Fast. Often I wait till its big enough to fully remove, because if its too small then i just pull out leaves and no root. Hate the stuff. Bane of my weeding existence


Ah yea that’s what it’s been like for me. I will probably try using some vinegar painted on or try the tweezers.

It’s strange how well rooted it is, as this growth just came up over the last month.

It took me years to eradicate these from my herd… I watch EVERY new plant for sneakers…
Never used vinegar, though it does work on real moss, larger amounts would acidity the soil…
On large stands, I’ve had real good luck with …taking a medium bristle art paintbrush, dipping into 10:1 diluted Roundup, and gently painting the ‘Irish’ moss. Don’t have the brush overly wet, or apply too much to wet the soil. Let the pot dry somewhat beforehand. Do not water for a day… It is tedious, but, there is a very satisfying outcome.
WAIT FOR IT…It takes a week for the moss to realy dry up and turn yellow. I dont pull it up.
Do this early in spring / summer, BEFORE the flowers / seed sets. The seeds are viable for several years. The pot temperature MUST be above 50F.
I STILL have new plants pop up. I use tweezers and fingers to pull up the plant WITH the root. DO NOT let them go to seed…
This process has NEVER affected any tree I have used it on.
Excess Roundup CAN kill trees. Use caution. Good luck…

Ok good to know, thank you. I have some round up, so I may try that method with the paint brush.

When you’re saying not to let them go to seed, are you referring to that round knob at the end of them?

There’s a few that have that already. Luckily it’s never spread to any other trees I have, although last year I did pull some out by hand and just threw them into another container of dirt and of course it grew there.

Yup, them little nobs…pull the entire plant WITH tweezers and discard. Don’t compost…
I just took thirty plants off five bonsai… only one had the flowers. Musta hid last fall and overwintered…:fearful:


Ah alright. Yes will do it this weekend. Thanks for the help!