Chinese Elm - Needs Help

[moved on]

Hi All,

I'm fairly new to bonsai but have bought a few successful trees over about a year. This Chinese Elm has always been a bit of a problem. As soon as I got it home it shed a lot of leaves but it never entirely recovered its full canopy. It now looks very spartan compared to the others which are thriving. I monitor my bonsai water levels with a meter to avoid over-watering and they are located at a South-facing window (they are usually inside but, due to the heat indoors, I have placed them on a window sill in the image). However, this Elm has leaves that quickly turn a mottled yellow with spots and fall off (these spots are not spider mites, I have checked).

I've noticed recently black markings (and holes) on its leaves and think it could be black spot. I also suspect that the pot is too small for the Elm (although I bought it not long ago). Perhaps this is worsening the problem. The soil looks a bit fusty too. It's strange as I have other Chinese Elms given the exact some treatment that are doing great. I just don't get it. Any help or guidance would be greatly appreciated as I'm at my wits' end with this plant - it's definitely becoming the problem child!

 

[Shibui]

Pests and diseases are almost always worse inside. Sun is one of the best fungicides and outside conditions are what trees have evolved with.
The pot is not too small for the tree but it may be a little small for a beginner to manage. Small pots need better bonsai knowledge and techniques. Looks like it has not been repotted for some time and that will probably be contributing to your problems. Cutting back the roots gives room for new roots to grow. Fresh potting mix allows better air and water circulation which trees need. Far from hurting a tree, they usually seem to grow more vigorously in the year after repotting.
I know some growers repot Chinese elm any time of year but mid summer is probably not the best time for beginner to repot. I would probably just nurse it along until next spring then repot.

 

[fviljoen963]

The only thing I would add to Shibui's post is a good systemic fungicide like Kohinor

 

[Zach Smith]

The tree should be outdoors. You're asking a lot of a temperate zone tree by keeping it inside. As others have noted, it probably needs repotting. It doesn't look in bad enough shape to need an emergency repot now, but this should be a priority next spring. Chinese elms are pretty tough, so you should see fresh growth within a week of relocating it. Good luck!

 

[WNC Bonsai]

Unfortunately chinese elms are often sold as “indoor bonsai”, in general they are not. Smoe folks have managed ot grow them in doors but it takes special care, lighting, watering, soil, etc. and is not something for a beginner to attempt. One reason for the confusion over these plants is in China they have a large range growing from the sub tropics to the temperate zone regions. This means there is a wide range in their ability to handle indoor and outdoor conditions. Here in Asheville NC they ae grown as landscape trees or as outdoor bonsai. If you can find a variety that is from the Chinese sub tropics then you might be able to successfully grown it indoors. But one from the temperate region will not do well inside any more than an English elm would. Most growers however don’t know the genetic history of their nursery stock so it is unlikely you will be able to know which yours is—thus the confusion.

 

[Forsoothe!]

If you want indoor bonsai, buy tropicals. Anything hardy outdoors in London need the rest they get over winter to look good and be happy. Even tropicals will need some outdoor time in summer to regain vigor lost indoors over winter. There is no bonsai-able plants that will grow well indoors year-around forever. Figs and Dwarf Schefflera arboricola are your easiest starters for apartment dwellers.

 

[moved on]

Thank you everyone for your advice. I have now moved the tree outdoors to a sunny spot.

I will hold off on re-potting until the spring as suggested. If it doesn't improve, I'll try a fungicide.

It's bad that they're sold as indoor plants as I asked the seller specifically at the nursery for trees that would tolerate being indoors and that would be good for a beginner. I won't use them again.

On a happier note, my Chinese Sweet Plum and Ficus bonsai are doing great at my window!

 

[WNC Bonsai]

If it has been indoors don’t move it directly to a full sun location, you need to do it in steps giving it more sun every few days. Otherwise you risk leaf burn.

 

[moved on]

I came back home tonight and saw a wonderful thing:



Magellan (my Chinese Elm's name - don't judge!) has new growth all over him. It's amazing that just after a day in partial shade outside he's already looking so much healthier.

Thanks everyone! It looks like Magellan isn't going to share the fate of his namesake after all!

I don't think his leaves will burn where he is; as I said he's in partial shade and has been sitting outside in the Sun in the evenings prior to moving him outside.