Stratiotes aloides
Water soldier
Common names: Water aloe
At a glance
- Light
- Full sun
- Lifespan
- Perennial
- Flowering
- Jun–Jul
- Hardiness
- Hardy
- Origin
- Native to Germany
Photo: Jörg Hempel · CC BY-SA 3.0 · Source
Description
Stratiotes aloides, commonly known as the water centaury or water aloe, is a native floating aquatic plant that forms a rosette of sword‑shaped, serrated leaves reminiscent of aloe. For most of the year it drifts just below the water surface; in summer the rosette rises to display delicate white flowers. It provides habitat for dragonfly larvae and other aquatic organisms and is considered an indicator species for clean, low‑nutrient water. The species is legally protected in Germany; wild specimens may not be taken, but cultivated plants sold commercially are safe for use in private ponds. The sharply serrated leaf margins give the plant its name and require careful handling.
Care instructions
Plant the water centaury in still or slowly flowing water with a depth of 30 to 100 cm, preferably in a sunny to partially shaded spot. The plant regulates its buoyancy and will sink to the bottom in autumn to overwinter, rising again in spring around mid‑April. It does not need a substrate or fertilisation; it absorbs nutrients directly from the water, so overly nutrient‑rich conditions should be avoided. In summer, remove excess daughter rosettes that form from runners to prevent the water surface from becoming overgrown. A winter with an ice cover is harmless as long as the water does not freeze solid.
The care notes were machine-translated from German.
Garden year
FloweringJun–Jul
Soil & site
Soil pH
Soil type
moist, nutrient-rich, loamy, clayey
The water soldier needs no soil in the classic sense, because it floats freely in the water and takes its nutrients directly from it. Nutrient-rich, slightly alkaline to neutral water with a loamy-clayey pond bottom suits it best. In very nutrient-poor or strongly acidic waters it hardly grows.
Feeding
Medium feeder
The water soldier is not fed directly, as it supplies itself via the pond water. A moderate nutrient content in the water, for instance from rotting leaves on the pond bottom or a thin layer of pond soil under gravel, is entirely enough. Water that is too rich in nutrients encourages algae rather than the plant itself, so it is better to stay restrained.
Overwintering
In late summer the water soldier forms heavy winter buds that sink to the bottom and survive there, protected from frost. In spring the buds rise back to the water surface by themselves and sprout anew. The pond should not freeze through completely in winter; a water depth of 60 cm or more gives enough security.
Propagation
Methods
- Offsets
- Division
The easiest way to propagate the water soldier is via the daughter rosettes that the plant forms on runners; in summer you simply separate them and let them float elsewhere in the pond. Larger plants can also be divided by carefully splitting the rosette into two rooted halves. Raising it from seed rarely succeeds, as the water soldier usually occurs with separate sexes and needs both female and male plants within reach. For a garden pond, vegetative propagation via runners is the most reliable method.
For your garden
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