Underwater plants are usually rather inconspicuous, but perform important tasks in the garden pond. Underwater plants or submersible plants are often the most inconspicuous and at the same time most important plants in a garden pond. They usually float submerged and often floating freely through the water. So you don’t get much from them, but they also perform important tasks underground, evergreen representatives even all year round: they produce oxygen, consume excess nutrients, bind dirt and serve as food and shelter for many water dwellers.
Tips for planting and caring for underwater plants
Keep an eye on the stock and simply fish for lush colonies. For species that are firmly rooted in the soil, it often helps to put them in a planting basket and not simply to give shoots into the pond. Because so, without soil and pots, but in a container filled with water, many underwater plants are offered on the market. You just pour them into the pond. The necessary water depth depends on the species, but generally submersive plants are made for the deep water zone. It starts at 40 to 50 centimeters below the water level and reaches to the pond sole.
The year-round green water star (Callitriche palustris) shows dense upholstery with narrowly leafed shoots, most of which swim underground. Rosettes form at the tip of the shoot, which lie on the surface of the water. Ideal are low-calcareous, standing and only slightly flowing waters with rather low depths of 10 to 50 centimeters. Even lower water levels are maintained, under certain circumstances the plants then form landforms with modified leaves.
The horn leaf (Ceratophyllum demersum) is a mostly free-floating plant whose shoots, which are up to one meter long, sometimes anchor in the soil with the help of fine sprouts. It does not form roots. The slightly fragile shoots are richly branched, with dark green leaves that reach up to 25 centimeters in length and stand in quirles. Flowers rarely form when, then they are inconspicuous. The underwater plant feels most comfortable in standing or at most slow flowing and very nutritious waters in semi-shade. Sometimes it can also proliferate. Ceratophyllum produces a lot of oxygen and is therefore ideal to counteract the formation of algae.
Canadian Water Plague
The Canadian water plague (Elodea canadensis) also moves at a depth of up to 200 centimeters. The persistent, hardy underwater plant has meanwhile also spread in Central European standing and flowing waters and often distributes native species there. Its 30 to 60 centimeter long shoots are densely studded with dark green leaf quirles and rarely root in the ground, but swim freely under the water surface. The tiny white flowers appear between May and August, they are inconspicuous, but – as they are lifted over the surface of the water – visible.
The deciduous quirl-leafed thousand-leaf (Myriophyllum verticillatum) is native to us and can be found in slow-flowing as well as in standing waters. In garden ponds, the underwater plant often needs some start-up time or the best conditions to establish itself: Ideal is soft, nutritious, low-lime and above all very clean water. The water depth should be between 50 and 150 centimeters. The shoots of Myriophyllum, up to two meters long, float under water with the finely pinnate leaves arranged in quirles, up to the tip of the shoot.
As a native underwater plant, the water spring (Hottonia palustris) can be found in natural ponds, lakes and other calcareous and shaded standing waters. Just below the surface, it forms lush, cushion-like colonies of light green, richly branched, dense and finely leafy shoots that are rooted in the muddy soil. A depth of up to 50 centimeters is preferred. Only then do the pretty, white-pink flowers develop in May/June, which – unlike the leaves – protrude far out of the water.
Ordinary water hose
Utricularia vulgaris, the common water hose, is one of the carnivorous underwater plants. Mosquitoes and other small animals are sucked and digested at lightning speed when touched into special trapping bubbles that hang on the leaves. The native plant comes from nutrient-poor bog ponds, but also appears in nutrient-rich, quiet and weakly flowing waters. The deciduous leaves are threadlike and have a prickly edge. Utricularia is a submerged water plant that only “appears” during the flowering period between April and August.