They all show promise! I do really like that overarching elm branch. I tried to think what could be removed but I like the overall "pipework" look, although to me it more closely resembles a haunted tree shape. The lack of leaves certainly add to this!
The looking lemon tree reminds me of all the ones I've lost, but luckily I still have their mother. Many were lost in bonsai experiments/practice. However, the better and more recent ones were killed due to my caretaker friend being careless while I was on vacation. Now I never want to go on any extended trips...
The worst part is when people say, "I don't know if it's dead or not..."
WHAT DO YOU MEAN‽
it's completely dead...
(The leaves looked like those of your Chinese Elm and the soil is bone dry and hardened into a single cake!)
That is interesting about your citrus trees. Were they grown from seeds or cuttings of the mother tree?
What I did for my citrus was to make sure the soil was so porous, it would be impossible to overwater.
The mother, which I'm now pretty certain is a limo (lima tree), was planted from seed. But all the ones I lost were just cuttings from it. They died from lack of water. My friend had neglected everything for a couple of weeks.
My neighbors let me have some cuttings from their tree, which is a lemon tree. But I've been procrastinating while they're just sitting in water. I had planned to try grafting at least some to my mother tree.
What does your soil mix consist of? Mine always tends to be too heavy. Do you use lots of perlite?
Coir and perlite or pumice, and a little activated charcoal to balance fertilizer and pH. A little bit of sphagnum moss near the bottom roots provides some extra protection from dry indoor air.
No compost or smelly organic fertilizers. The outdoor microbes will die indoors anyway, so you end up with a fly problem once it starts leeching compost juices.
Liquid fertilizer and slow release Osmocote pellets are best, in low doses, or none when the tree is transitioning or sick.
You can try lime again. I know mine died a few years ago because the soil was too much wet organic matter (peat). A hardy variety might survive better year after year. Persian Lime I think is what local nurseries sell for our climate.
Store bought cactus/citrus soil has worked well in my experience in larger scales. It's good, really available, and serves as a nice low maintenance soil for periods when it just needs to leaf out. Not that heavy. Generalist stuff.
I will apply your tips in my next generation of bonsai clones. Small amounts of the big bag soil really fluctuates unpredictably in terms of moisture content.
Yeah that sounds like it will work. Rooted cuttings probably need no fertilizer at all. Just keep it covered with a cup or humidity dome if you can. Same with a graft, keep it tightly wrapped in plastic.