[tsunami]

I believe that glass/plastic dividers are usually used to contain plants that spread with runners.

With those two plants, you will need to thin them out reguarly. However, I don't see a glass divider doing much good as the Hemianthus micranthemoides can easily grow up and over it. IMO, I would just prune them regularly to keep them tidy.

There is nothing wrong about having a few spikes of hairgrass poking out of your Hemianthus micranthemoides, though. Nothing wrong with some sprigs of H. micranthemoides spreading into your hairgrass. The small transition from one plant grouping to the next looks natural, IMO.

Unless you are trying to create a Dutch tank with regimented, homogeneous groupings.

Carlos

 

[tsunami]

Micranthemum sp. (Hemianthus sp.?) does grow much more upright than H. micranthemoides. IME, I found it to grow every bit as fast as the four leaved per node variety. Either way you look at it, you're going to have to prune these stem plants at least weekly.

Carlos