We sow seed and subsequently grow plants on a medium consisting of acidic, fibrous peat moss and mild, nonalkaline sand (1:3). We sometimes add cut dry Sphagnum, perlite, vermiculite or milled charcoal, but this is not necessary. The plants tolerate loamy-sandy planting medium too. Plants grew very well in a sample of this soil we imported from the locality near Ubrique. We always use unglazed ceramic pots 12 cm or more in diameter. Some stems of sphagnum are put through the drainage hole to act as a wick. We fill a pot with the planting medium to 2 cm below the edge and press the substrate down. The filled pot is placed in a tray of water to moisten the substrate. Now we are ready to sow the seed.
The minute black seeds have a hard seed coat. For successful and quick germination, scarification is necessary – you must scratch the seed coat. We recommend the following methods:
A) Before sowing you can soak the seed in water or 0.1% solution of giberellic acid (GA3, stimulator of germination) for 24 hours. Then you carefully cut very thin slices of the soft seed coat using a knife blade. We cut at the peak of the seed, while other authors recommend cutting the side or a wider part of the seed.
B) Dry seeds can be abraded using sandpaper or a rasp. This procedure crushes up the hard seed coat. It is better to use method A).
C) You can sow the seeds without scarification and place them in a heated greenhouse. Seed will naturally germinate in the spring. While method A) allows a more precise timing of germination, method C) unfortunately does not.
Prepared seeds are sown on the moist planting medium in 3 – 5 pits about 1 cm deep (dug by a finger). We put one seed into every pit. The previous recommendation of placing the pot in darkness (Studnička, 1984a) has been found to be unnecessary. In our experience the seeds germinate at the same rate when exposed to light. The statement that only one plant should be left in a pot after germination is also untrue. We always grow several plants (1 – 5) in a single pot without any problems. Their growth is comparable with the plants potted up individually.
Seeds germinate in ambient or slightly higher air humidity conditions within one or several weeks. Too high air humidity leads to death of the germinating seedlings. If seed is treated with giberellic acid (GA3) they will start to germinate after one week. Otherwise, seed germinates within 2 – 3 weeks. As soon as the seed germinates you must decrease air humidity and increase air circulation. Also we add substrate to the germinating plants so that we cover the sowing pits with the substrate and replenish the surface of the pot. High air humidity will certainly kill all the young seedlings. Drosophyllum requires maximum light. About 40% of the germinated plants die during the first 2 – 3 months.