Planting Acorus in a Riparium Planter
Japanese sweetflag (Acorus gramineus
) is an excellent riparium plant. It is a true marginal aquatic that grows along streams in mountains, so it adapts well to riparium conditions. Sweetflag has tidy, grass-like foliage that looks especially good if repeated in several planters and used as the main background plant combined with a few other different plants for contrast. I have had the best results with the cultivated variety, A. gramineus
'Ogon'. This cultivar is often available for sale as a pond plant or bedding plant and it has leaves striped with lime green and gold. 'Ogon' grows to about 14" tall with leaves that arch gracefully over the water's surface, a size and shape that works very well with most riparium layouts.
While it is pretty easy to grow in a riparium planting, Japanese sweetflag has a unique kind of growth habit. I offer here a few details that might be helpful for getting it started in riparium planters.
Tt has grass-like foliage, but sweetflag is not a grass and it is instead in its own group of plants. Sweetflag grows from a creeping rhizome, much like as Anubias
plant. This is an important detail, as will be demonstrated in this series of photos.
Sweetflag is often sold potted with many rhizome branches crowded together. I like to use a sharp blade to divide into rhizome sections about 1" long and with a few roots. This picture shows a division with roots rinsed clean of potting soil. The scissors is used to trim the roots back to about 3" long so that they will fit in the riparium planter. Trimming of long roots encourages new root growth.
The rhizome should not be buried in the substrate, but instead positioned on top so that it can creep forward as the plant grows. The following photograph shows the base of the rhizome seated against the rear of the riparium planter so that it will have some space to root down into the substrate as it grows forward.
The riparium planter has been filled to the top rim with gravel substrate. Notice again that the rhizome rests on top of the gravel substrate.
Since it is planted at a shallow depth and since the sweetflag divisions usually have just a few roots, the new plant will be top-heavy and prone to tipping out of the riparium planter. Use a couple of rubber bands wrapped around the planter to secure the sweetflag for a few weeks until a new roots have grown to anchor the plant.
Japanese sweetflag grows easily in a planted riparium. It will be happy with moderately bright lighting and some extra ferts in the aquarium water.