- Approximate height: Leaves float on the water surface
- Recommended water depth over crown of plant: 15 - 45cm (6 - 18 inches)
- Flower: None (insignificant)
- Supplied in the solid 9cm pot we grow them in - for best results we recommend potting on into a 1 litre pot
This pretty British native oxygenator has small rosettes of green leaves, approximately 3cm across, which float on the water surface. Below these are finer, more elongated, leaves on delicate stems. Unlike many oxygenators, it stays in leaf all year, not even minding when its surface leaves are frozen overnight into the ice (the fifth picture shows the plant frozen solid into ice in January). It is a good oxygenator for small spaces, as its growth is not particularly fast, its foliage is soft and dainty, and it is easy to control. Its fine foliage will not compete well with algae, so it is better either in an established pond (a pond that has been set up for two years or more), or in a shady place. If it is going in a new or sunny pond, check it occasionally to ensure it is not being swamped by algae. It is also not really suitable for ponds with fish, or at least any fish other than very small ones, due to its very soft foliage.
Please note that these are potted plants; Callitriche is usually sold as loose stems because these are very easy for nurseries to crop and sell, but this is a delicate plant and loose stems are not likely to survive and root.
We grow these in fairly shallow water here at the nursery, so would recommend having no more than 6 inches of water over the pot at first. If you would like the plant to go deeper than this, lower it gradually, allowing the leaves to reach the surface each time before lowering it again. (House bricks or pots filled with gravel can be used to raise plants to the required level).
A note on taxonomy: This plant is usually called Callitriche stagnalis. However, the taxonomy of the British Callitriche species is complicated; it can be difficult to distinguish between species and it is possible that the name Callitriche stagnalis is applied to more than one species. We acquired this plant many, many years ago when even less was known. Hence we have just used the primary name of Callitriche.
If designing a planting scheme, we recommend approximately 1 Callitriche plant per square foot of water surface. Read more on how to pot and care for your plant.