Recently acquired Chinese Elm is yellowing it’s leaves on half the tree. I recently repotted and placed in partial shade. Its I’m partial native soil and surrounded with Bonsai soil. Gets watered every day to every other day. Now with the summer rains coming I will be able to water less with the hose and rely more on the rain. Not sure why it’s yellowing so much other than I May have waited to late to repot. What can I do ?
When you describe the tree being in its native soil surrounded by Bonsai soil, it sounds like a slip potting. Common practise in the nursery trade, however creating very difficult circumstances for bonsai. The difference in the media normally creates a center that stays either to wet or to dry. The other issue is that the roots unless combed out at the edge for a distance have trouble extending into the bonsai soil. The yellowing suggests the centre is likely staying to wet at this time.
Effective in the nursery trade when the same media is used on the outside, ineffective in that the root ball remains congested in the core and difficult to adapt for Bonsai.