Eriocaulon - Collecting and Germinating Seed
Many hobbyists multiply Eriocaulon plants in their aquarium by plant division (the separation of plantlets from a mother plant). This method is reliable but can be slow in building up plant numbers. An alternative is to grow plants from seed, which is both rewarding and an efficient method to propagate Eriocaulon species.
Seed harvesting and storage is a good way to maintain finicky types, long-term. The process of seed collection and propagation is relatively straightforward.
Flowering: Eriocaulon can flower while growing submerged, but the best chance of collecting seed is through growing some plants emerse. If you’re not ready to embark on emerse growing, an easy alternative is to grow plants in shallow water as emergents, with the upper part of the plant (and its inflorescences) growing above water.
Harvesting the Inflorescences: Allow flower heads to mature fully before harvesting to ensure seed viability. Wait for some to start falling apart, then collect the oldest/largest flower heads and place these into a paper bag and leave to dry for a week or two.
Seed collection: A small number of seeds may fall from the dried seed heads without assistance, but manual removal is required to maximise seed harvest. Place the dried seed heads onto a sheet of aluminium foil (or paper). Rub each seed head between thumb and index finger to break it apart and release the dust-like seeds onto the foil. The foil now holds a mix of seeds and flower debris. Gently blow to remove the light-weight debris without blowing away the seeds. Once clean of flower debris, the foil can be folded to allow you to pour the seeds into a storage container. Cap the container and store it in the fridge until the seeds are required for sowing.
Seed sowing: The biggest challenge to germinating such fine seeds is controlling algae and fungus taking hold on the surface of the moist propagation media. To minimize this, sterilize the media in boiling water for a minute or two. Tankquility uses a commercial peat/perlite propagation media for sowing fine seeds like those of Eriocaulon. Place the damp sterilized media into a clean seedling punnet (preferably sterilized) and tamp the media down to achieve a flat even surface. Sprinkle the Eriocaulon seeds from the storage container onto the surface of the media (a minimal amount is required, as heavy sowing can be detrimental). Finally, using a trigger spray bottle filled with sterilized water, mist the surface of the media to bed-in the seeds. Place the seedling punnet into a sterile rectangular take-away food container, attach the lid, and put under artificial lighting at between 20°C and 25°C (our plant room is set to 23°C). Mist the surface of the media after a couple of weeks and await germination.
Germination and Growing-on: By following the procedure outlined above, the first green shoots should appear on the surface of the media after a month or so. About two months after germination the seedlings can be pricked from the propagation media and planted into a growing media (we use Fluval Stratum).
The pictures below show seedlings of Eriocaulon quinquangulare germinated using the procedure outlined above. Germination time was about 5 weeks (37 days), and the seedlings are 20 days old at the time the pictures were taken.
