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Propagating and growing Drosophyllum lusitanicum
Drosophyllum is a highly desirable carnivorous plant which is rarely found in most growers collections. The reasons for this include the fact that Drosophyllum cannot be reproduced by any other means than seed, it is very sensitive to movement and will often die even if great care is taken to protect the plant, and it is sensitive to water levels, preferring a much drier soil than most cp's. Finally, seedlings and adult plants produce phytotoxins which inhibit the growth of other Drosophyllum grown in the same pot or even nearby in a greenhouse.
Given the above drawbacks, it is not surprising that this plant is not easily obtainable commercially. However, once it has passed the critical seedling stage, this can be quite a magnificent plant to have in the greenhouse, and if not disturbed, will thrive for many years. Through discussions with one grower who has been relatively successful, I have discovered some hints on getting this plant to the adult stage, and keeping it that way.
Soil
Drosophyllum appreciates a relatively open soil mixture, with very little peat moss. A good mix is equal parts of sand, perlite, and vermiculite. When kept moist, seeds germinate quite readily and grow until about 1 inch high. At this point, they often succumb to damping off disease, a fungus that attacks the roots of young seedlings. The grower I talked to had such a simple solution, it surprises me that the majority of us never thought of doing this before (including myself). That solution is to prevent the fungus from ever having a chance to germinate from the spores in the soil by sterlizing the pot and soil itself.
The best method for doing this is to put the entire pot with soil into a pressure cooker. Sterilize for at least half an hour, and definitely let it cool down before planting the seeds. The seeds should be sown as soon as possible, as the soil will be open to contamination immediately upon exposure. However, it will take significantly longer to get to the point where the fungus can harm the plant, at which time you've hopefully got some sturdy juvenile plants that can resist the fungus. The pots can be kept in a covered aquarium which has been cleaned with a mild bleach solution and rinsed out. This will also cut down on fungus problems.
Seeds
Unfortunately, Drosophyllum seeds do not readily germinate without a bit of help. While GA3 (gibberelic acid) and pouring boiling water over the seeds does work, the easiest and cheapest method is to take a slice off of the coat. Of course, then you have to worry about how big a piece you are removing! Just a small slice off of the larger end will do.
Care of seedlings and plants
Drosophyllum grows incredibly fast. Flowering plants can be obtained in just over a year, but sometimes they will flower within their first season. Remembering that they produce phytotoxins, the first thing to do once the seedlings are about 2 inches high is to remove all but the one healthiest individual. This may be hard to do, especially with the work put into it, but is necessary if you want any of the seedlings to survive at all!
Once the remaining seedling reaches a height of about 6 inches, you may need to repot it in a larger container. Contrary to popular belief, the plant can be removed and put into a new pot, provided you do not significantly disturb or expose the roots, and the plant is put back in the same position.
While Drosophyllum certainly prefers dry conditions, the grower I talked to had his in a bog garden with Sarracenia and other wet loving cp's. The Drosophyllum survived, but was not happy. The occasional overwatering will probably not harm your plant, but it's definitely better to keep it on the dry side.
Hopefully these tips will help you with growing a large, healthy plant that can be the envy of all of your cp friends!