Plants Cultivated on Stones and Tree Roots

by Claus Christensen

In Nature, some plants used in the aquarium grow naturally on stones and tree roots. Prime examples are Anubias, Microsorum, Bolbitis and Javanese moss (Vesicularia).

The typical biotope for such plants is the proximity to a waterfall; either the lake formed beneath the waterfall or the area around the waterfall which is continuously bathed in a fine mist or spray. The plants colonise fissures and hollows in stones and tree roots. With their special adherent roots known as 'crampons', however, they can anchor themselves so strongly, even to very slippery surfaces, as to be almost impossible to remove undamaged.

The idea of systemising the production of such plants was born in an aquarium shop. Plants were not a feature of the shop's aquaria as they were a nuisance when the fishes had to be netted and when the aquaria needed cleaning. The logical solution was to grow the plants on easy-to-move stones and tree roots! A trial production on Tropica was initiated.

Although aquarists have been growing plants on stones and tree roots for years, establishing a fast and efficient production system was far from easy. The production process is space-requiring, and the plants often grow so slowly that they take up to a year to reach their target size. Tree roots heavy enough to weigh down the plants had to be obtained in the right sizes and in a sufficient volume. And for reasons of freight the stones used could not be too heavy. So instead of chunks of rocks, lava imported from Iceland was chosen.

The shops purchasing the end-products were delighted. If their fish were difficult to catch they simply removed the plants and the rest was straightforward! But soon other benefits also materialised. Newly introduced fish acclimatised much more quickly to the tank environment - they assumed their natural colouring in record time and appeared less stressed. Sales soared!

But Tropica was soon faced with a new challenge. This arose when the shops had difficulty in explaining to customers that the plants were not for sale! Tropica were initially sceptical about the sales potential to aquarists due to the high price of the plants, which was a result of the difficult production process. In the event, however, the demand far outstripped supply even when production was substantially increased! Aquarists were more than willing to pay the high price in return for the advantages with regard to aquarium layout.

An aquarium can now be planted in no time while at the same time avoiding the newly-planted look! This, and the fact that the plants can be swapped around without retarding growth, has made them enormously popular for display purposes. The plants can also be 'stacked' and used to cover cables and other technical installations in the aquarium.

Many aquarists dismiss the use of fish bowls as totally unsuitable. And even bowl enthusiasts have to grapple with the planting difficulties caused by inadequate depth of substrate to hold the plant securely. Plants anchored to stones and roots provide an admirable solution to this problem, while at the same time they are naturally robust and require minimal light. The use of fish for decorative purposes is superfluous in such cases - the plant and the root are decorative in themselves!

The production of aquarium plants began with the cultivation of individual specimens, a practice quickly overtaken by the sale of plants in plastic pots. The production of plants cultivated on stones and roots - the 3rd generation of aquarium plants - is a natural continuation of this process.