Cultivation and describtion of Aldrovanda vesiculosa, the waterwheel-plant

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ALDROVANDA VESICULOSA

the waterwheel plant

Aldrovanda vesiculosa (the only species of the genus) is a very strange and amazing carnivorous plant. Once common throughout almost the whole "old world" it has now vanished to few places in India, Japan, Africa, Australia and Europe. It hasn't been recorded in Germany since 1986.
Aldrovanda is a rootless plant floating below the surface of small waterponds which get quite warm during summer. Aldrovanda prefers water which is very low in nutrients and and this is the main reason why it has become so rare in our agricultural dominated environment.

Some years ago the plant was very rare and thought to be extremly difficult in cultivation (Carow&Wrono, Braem, D'Amato). But with improved cultivation techniques the plant is relativly easy to maintain and propagate.

There are several types of Aldrovanda in cultivation, two Australian types (green and red), a Japenese clone and one from Poland (East Europe). I have grown the temperate clones from Poland and Japan which are building turions if the daylenght gets shorter and the water temperature lower in autumn. In nature the turions will sink to the bottom of the lake where water temperature will be 4°C during the period of freezing.
It is posible to grow Aldrovanda with avarage water temperatures of 25°C during summer and 10°C during winter. The plants are growing well and are dividing several times but they never flowered for me. It seems that they need higher temperatures between 30° to 35°C to flower.
The most important thing in cultivation of Aldrovanda is the water quality. The water should be only slightly acid (PH 6-7) and low in nutrients. But Aldrovanda needs some a high concentration of tanins and some minerals to grow well, especially Boron. I grow Aldrovanda in a small aquarium and use a mixture of loam, peat, dead reet leafes and pieces of broken clay pots as a ground cover. When this soil brakes down it releases carbon dioxid and minerals which Aldrovanda needs.
I also put in some living reet plants which will reduce the amount of nitrogen and phosphor in the water.
Finaly I add some water snails which will feed on the growing alges and are extremly helpful in controlling this "pest" which otherwise would overgrow and kill the Aldrovanda plants.

At the beginning of winter 2001 my Aldrovanda turions have accidetly been facing a freezing night with temperatures down to -7°C. They had been out of the water, lying on moist ground. All of them survived and started growing as usual in spring 2002.