Propagation
Propagating Aldrovanda
Propagating Aldrovanda, the waterwheel plant: break the rootless floating stem into pieces, and each piece carries on growing.
Aldrovanda propagates itself: the stem grows at the tip, branches freely and rots away at the back, and every branch that breaks off is a new plant. The whole skill is in keeping the water right, not in the propagation. Set up a sunny, peat-bottomed tub with companion plants and water fleas, let it settle, then drop in stem pieces of three or more nodes. Temperate forms must be allowed to form turions and rest cold over winter.
Fragmentation
Moderate
When: Summer, while the plants are growing and branching strongly; temperate forms are dormant as turions from autumn to spring.
Snap or cut a healthy stem into pieces with at least three whorls of leaves and float each in the same tub of peat-stained water. Side branches form on their own and can be broken off as they lengthen.
- Set up the water first: a shallow tub with 2 to 5 cm of wet sphagnum peat and leaf litter on the bottom and about 15 cm of pure water above it, with a few potted sedges or rushes to condition the water, left to settle for a week or more before plants go in.
- Lift a plant and break the stem between whorls so that each piece has at least three nodes; the growing tip and the branches are the best material.
- Float the pieces on the surface, keep the tub in full sun and screen it against mosquitoes and animals.
- Add water fleas as food and to keep algae down; change part of the water if it greens.
- Temperate strains form small dense buds (turions) at the shoot tips as water temperatures fall below about 16 to 18 C in autumn. Leave them to sink and overwinter outdoors, or collect them in October or November and keep them in a closed jar of the same water in a refrigerator at about 4 C until spring, when they resume growth within days of warming.
- Medium
- Soft, slightly acidic water (pH about 5 to 7) over a thin layer of peat and leaf litter; never deeper than about 15 cm.
- Conditions
- Full sun outdoors, warm summer water, Daphnia present; temperate forms need a cold winter rest.
- Time to result
- A single shoot can give 15 to 30 plants over a season in good conditions; counts of growing tips can rise tenfold in about a month in warm weather.
Watch out for
- Algae are the usual killer, especially for tropical strains kept indoors; shade the water with floating plants, add water fleas and tadpoles, and never let the tub stagnate.
- Water that freezes solid kills the turions; the tub must be deep enough or sheltered enough that only the surface freezes.
- Plants that stall, with pale, flattened tips, are usually short of minerals in over-pure water; a little clay or soil on the bottom helps.
Sources for this method
- Peter D'Amato, The Savage Garden, Revised Edition (Ten Speed Press, 2013), The Other Savage Plants chapter, Aldrovanda section. ISBN 978-1-60774-410-8
- Adamec, L. 1997. How to grow Aldrovanda vesiculosa outdoors. Carnivorous Plant Newsletter (accessed )
- Darnowski, D. W. 2002. A method for growing Aldrovanda. Carnivorous Plant Newsletter 31 (accessed )
- Growing Tips for Aldrovanda (Carnivorous Plant Nursery) (accessed )
Sources
References for the facts on this page.
- Peter D'Amato, The Savage Garden, Revised Edition (Ten Speed Press, 2013), The Other Savage Plants chapter. ISBN 978-1-60774-410-8