Newly Registered
Posts: 2
Joined: Wed Jul 15, 2015 4:07 pm
Location: New York

Best Bonsai Soil


I purchased an indoor Catlin Elm (Ulmus Parvifolia) roughly 7 months ago. The tree thrived until after I first pruned it- around 3 months ago. New growth has been much more sporadic, so there has been no reason to prune it since. I was sure I was pruning correctly, but I have not noticed any new buds sprouting where I cut the branch. I am also sure that I have been watering too much because the soil on top of the mossy mound around my tree has begun to sprout a white mold.

At first I watered my tree whenever it started to dry out, every 3-5 days; I read somewhere to never let a tree go completely dry. Then I read some articles and watched some videos about dunking the plant, which I tried three times and then decided it was causing the root ball to be too damp and from then on the moldy substance has started to spread further.

I've been reading up on HG on how to deal with this mold and have seen suggestions to remove the rocks and also the tree from the soil and to re-plant it in bonsai soil. I have no problem digging around to see if it needs transplanting. If my bonsai does needs transplanting:

1. Can I use the same pot the tree came in? There are two gorgeously-placed landscaping stones growing through the moss on top of the root ball that I'd like to keep intact as well (if possible).

2. Any suggestions of the best bonsai soil?

Please Help! I don't want this lovely tree to die!

Newly Registered
Posts: 2
Joined: Wed Jul 15, 2015 4:07 pm
Location: New York

I took some photographs of my tree... and cat. :roll:

User avatar
Super Green Thumb
Posts: 25279
Joined: Sun Feb 15, 2009 6:04 pm
Location: TN/GA 7b

Watering by immersion isn't bad to be sure all of the soil gets moistened. But it should only be done every once in awhile.
You were right about watering only when the plant needs it. You don't want all of the soil to get completely dry, but you do want the top part of the soil to dry some in between waterings.

Use the search box to find information on chopstick method.

And you can do a site search on bonsai soil and find tons of info already here. Have you read the bonsai info in the non-forum part of this site:

The Bonsai Learning Forum here has tons of good information, including a very detailed thread about bonsai soil here: ... =36&t=3422

Enjoy! :)

User avatar
Greener Thumb
Posts: 787
Joined: Wed Apr 29, 2015 8:35 pm
Location: Upper Piedmont area of Virginia, Zone 7a

Since it's summer, I think your elm would do best outdoors. Elms are really outdoor bonsai except under extreme winter weather conditions. Yours - besides the overwatering issue - may very well be suffering from insufficient light & indoor conditions.

Return to “Indoor Bonsai Forum”