I have two stone bookends I want to use to do a ficus over a structure planting. See the pictures. I want to use them back to back with a gap between as in the second picture. I anticipate there will be trunks and roots in the gap and I will thread roots through the carvings on the fronts.
But if I don't connect them in some way, over time the trunks and roots in the gap will force them apart and destroy the planting. I thought about letting that happen and ending up with a 'decayed' structure look but the stones themselves will always look undecayed so that won't work. If I am lucky in time the trunks and roots will fill the gap so it will won't be seen.
Any suggestions on how to permanently connect them 1/4 to 1/2 inch apart without it being visible?


Thanks, I like the idea. That is what I am going to do.
I think if I place the rods across the bottom, one one each end, and then vertically down the middle, top-middle-bottom they won't be visible and so allow for one or two failures over the long term. I realize that if eventually I have roots coming from above cascading over the outside of the stones they will hold them together.
My current decision is whether to use soil or long fiber sphagnum moss to fill the gaps. I plan on using tinfoil to encase them to force the roots that develop to grow against the stone and downward. Leaning toward sphagnum as I don't think it will stain the stone like soil might. Probably either will work.
Final task is to find cuttings of a small leaf ficus to use. I have a couple and just need to decide if I sacrifice part of them for this project.
Hi David. What about cutting clear acrylic rods to 1/4 or 1/2 inches length and using a construction adhesive (liquid nails, gorilla glue, etc.) to attach them to the stones?
You can find some on Amazon in different diameters: https://www.amazon.com/Plastic-Rods-Acrylic-Plastics/s?keywords=Plastic+Rods&rh=n%3A11260349011%2Cp_n_feature_seven_browse-bin%3A3071216011&c=ts&ts_id=11260349011