I've been working on a new(ish) concept for a couple of years and just starting to see more convincing results from some of my trees. Indoor Espalier is an adaptation of traditional espalier tree training to create indoor living wall/vertical garden features with artificial light.

Among other parts of this is a planter mount assembly that positions as close to the wall as possible to maintain the 2D effect. So far I've had good results with a simple potting soil made of one part pro mix + one part coarse perlite. The trees are illuminated with energy-efficient PAR-base LED lamps, which support growth very well.

I have started the Indoor Espalier with a few different indoor-adaptable fruit trees, including Ficus carica, Black Mulberry and Loquat, but the citrus have made the most progress. The biggest established tree in the photos below is a Calamondin, while the one with the fine leaves is an Australian Finger Lime. I also recently started a Citrus hystrix.

I'll add more progression photos as these specimens continue their development. It really has been gratifying to watch them take shape as espalier trees.

and why exactly do you post this on a bonsai forum??

leatherback wrote: and why exactly do you post this on a bonsai forum??

Because it is related as a way to train trees for a visual effect. And some of the theory and methods overlap. I thought there might be interest here.

But nevermind. I will depart.

Moderator please just remove this thread.