How can I restore foliage in a Chinese Elm bonsai?

Question

My Chinese Elm bonsai lost its foliage from the time of purchase (June) until now (November):

Roots seem fine (i.e. not rotten):

Is there something I can do (e.g. re-potting, pruning, feeding, wiring, etc.) to bring back its foliage? The loss of foliage could have been my fault (please see my other question).

How I cared for it so far:

• Initially watered it every second day; since last week, I've been using the chopstick method and have not watered it since. I'm waiting for the chopstick to come out completely dry.
• I fed it with a 4-6-6 feed every fortnight until last month; I haven't fed it for a month and I was planning to feed it monthly from now on.
• I pruned it twice during summer. After it lost most leaves, I realised the thiner branches are quite fragile. This week I removed all branches that had no leaves or only 1 or 2 leaves on the tip.
• It's still in the same pot it came in.

About the bonsai: 7 years old (according to retailer (Amazon)); now it takes about 1 week to re-water (the necessary time for a chopstick to come out completely dry); it stays by a well lit window in my kitchen, where it's constantly 20C; humidity in the flat stays around 60%. I'm in Scotland, so days are getting shorter quickly.

Answer 1

I have grown a few bonsais and trees and the number one factor that seems to affect their growth, at least as far as I have seen, is the Nitrogen content. Usually bonsais don't like extremely nutrient soil; however leaf foliage is usually affected by a sufficient amount of nitrogen in the soil. Phosphorous is more for flower growth. So your fertilizer (4-6-6) is higher in phosphorous and potassium than nitrogen. You want to use a fertilizer that is higher in nitrogen.

Answer 2

Chinese Elms do best when grown outdoor. It is not considered a tropical tree. You may want to look into a Fukien tea, ficus, or some other species that has good track record of doing well indoors.

Answer 3

Re-pot the tree in a 2 or 5 litre pot with fresh well draining soil and let the soil nearly dry before watering try to avoid feeding the tree.

if all the leaves fall off do a small scratch test on the trunk and main branches ,if you see green then your tree is still alive.

Answer 4

Shouldn't some bonsai trees be outside during the summer? I had a friend who lived in Inverness and had several naturally found bonsai in his garden. He left them out all year in all types of weather and they did fine. However, being gathered from the wild is probably the best thing too, I'm not sure how a Chinese Elm would do that far north?

I would ask the supplier for advice or see what he does with the other trees on display. The most I've seen here have been outdoors most of the time, but it's worth asking. You could ask any horticultural organisations or bonsai clubs online too. There are plenty down south. There are also botanical gardens nearby, and several up north, and you could ask people there.

As far as how cold it gets in the winter in Scotland, it depends where you live. Often enough it's the left side that gets the gulf streams and the warmer than usual winters, and the right side that gets the very cold winters from mainland Europe.

I've been to gardens with all sorts of South American trees growing outside in Shetland, and that's geographically the same as the southern most tip of Greenland. The place I worked at and a guy I knew had these bonsai in Inverness, which is again geographically further north than Moscow! There's a volcanic island called the black isle near Inverness that never really allows snow to settle on it during the winter. Having a local climate can offer some strange solutions for people wanting to grow trees in sheltered spots. Scotland can be an enigma!