Sundew (Drosera) Cultivation Information
Germinating Drosera can either be extremely easy or difficult depending on the species. All of the species start from incredibly small seeds that need to be handled with care. Research the species you are trying to start to find out if it requires cold stratification or some other treatment to have good germination rates. Sow the seeds directly onto your desired medium and keep the pot moist and in a humid location. Mediums for Drosera tend to be Peat/Perlite, though some species prefer more sandy soils. Most species will grow in Long Fibered Sphagnum Moss, though the more desert adapted species will likely rot in these conditions. Fungus can attack, so airflow is key, but not extremely necessary. A quick spritz with a spray bottle on a misting setting every few days will prevent most fungus from establishing. Germination can take a few days to a few months depending on the species. For best results temperatures between 70-80F, humidity around 70-80%, and at least 14 hours of light are needed for most species.
The seedling phase is relatively easy going for most Sundews. The difficulty comes from their small size and difficulty that comes from spreading the seed when sowing. It's a usual site to have large clumps of seedlings sprouting up together if a large amount of seed was sown. To best combat this, a patient and steady hand is required along with forceps or tweezers. Carefully remove the small plants when they've grown at least 6-8 leaves, once again for most species. Some species will only produce a few leaves at a time, so usually after 1-2 months post germination is a good timeframe to repot. After that point, the plants start to overcrowd each other and stunt in growth. Keep seedling Sundews in an environment of 72-80F, 50-70% humidity, and with 300 ppfd of blue lighting. Some species can grow under red/blue, but this is not a general case for the whole genus.
The adult phase of most Drosera happens within the first year of growth. The first curly flower stalk is the signal the plant has reached maturity. While the flowering displays vary from species to species, the one consistent factor is that they are usually rather short blooms. It's a common practice to cut the flowers off more prolific species such as Drosera Capensis or Drosera Spatulata in order to prevent their unintentional spread throughout a collection. Unhealthy Sundews may flower as a desperate last resort if they are unhealthy. Generally speaking, Drosera should not lose mucilage or look unhealthy from flowering. If yours is, seriously consider cutting the flower stalk before it is too large to help preserve the plant's energy. The “dew” is the best indication of health for a Drosera. Typically it will return within 2-3 days after shipping, 2-3 weeks at most. Outside of dormancy periods, Drosera will always have their dew present on newer foliage. If only parts of the leaf are producing dew, light, humidity, or pests are the usual issues. Poor medium, water, or airflow will cause the same problems as well. This makes Drosera a great indicator for a new collector, as a healthy Sundew means conditions are right for most other carnivorous plants!
Propagation
Sundews are some of the easiest to propagate carnivorous plants. Some species can quickly become weeds due to their ability to self pollinate without any help. This is compounded by the fact Drosera usually produce immense amounts of seed. As always, this is a major generalization. Sundews are incredibly diverse, with some species requiring manual pollination or cross pollination from a genetically unique specimen.
Other species, such as the Pygmy Sundews, have adapted to focus on more unusually strategies such as producing gemmae that explode of the central rosette. Due to this incredible diversity, it makes it difficult to give precise information on the specific methods for each species tedious. Generally, touch the yellow anthers to the white stamen in the center of the flower. You will see the yellow pollen on the stamen if you were successful. Paintbrushes can be used, but almost every method I've tried is tedious to say the least. Thankfully, since most species self pollinate readily, this isn't a problem you'll encounter with every Sundew.
Asexual reproduction of Sundews is incredibly easy and quick. Using a sealed container, like a sauce cup, jello shot cup, test tube, or kitchen container anyone can have success. For most species, leaf cuttings are the go to method for reproduction. Cut a healthy and preferably newer leaf and place submerged in water in a sealed container. Keep under shaded light and within a month to two months most species will form small bumps and new plantlets will form. At this point the plantlets can be transferred to a prepared pot with your preferred medium. Keep the plantlets in conditions that are incredibly humid, 80%+, for the first month. Fungal issues can happen, so increase airflow gradually and reduce humidity after 3-4 weeks. Once the humidity is near the normal for your collection, transfer the newly cloned Sundews like you would seedlings to avoid over crowding.
It should be noted that some Drosera are best cloned from leaf pullings, similar to the Venus Flytrap. Petiolaris and Pygmy Drosera in particular can only be cloned by either their normal vegetative divisions/gemmae or leaf pullings. Pull downward on the desired leaf and make sure to get some of the white stipule on the end towards the center. This tissue is the only area where new plantlets will sprout, unlike other Drosera that will sprout plantlets from their carnivorous pads. Tuberous Drosera in general also prove difficult to clone, as they usually do not have enough time to establish before environmental pressures force them to go dormant.