Hi all,
Thanks for the kind comments. I have compiled a brief growing guide, which I hope will be of use:
• SUBSTRATES: this year, I have experimented with a substrate of approx 1:1:1:2:2 peat:loam
ordinary houseplant compost
perlite:lime-free silver sand for the annual species. I believe that the addition of some nutrients to the substrate in this way encourages vigorous growth and branching. I grow B gigantea in a standard peat:lime-free sand
perlite mix.
• POTS: large pots are absolutely necessary for B gigantea and desirable for the annual species
• SUNLIGHT: full sunlight is best, although I start my annuals off under envirolites in a heated terrarium, as the light levels in winter/early spring are insufficient. Plants brought from the terrarium into direct sunlight tend to branch particularly vigorously.
• GERMINATION: I always use GA3 for all species except for B liniflora. B gigantea do best with a 3-4 day soaking. 24 hrs is enough for the annuals. Substrate and light levels as above. The annual species seem to germinate best and grow best as seedlings in warm humid and bright conditions with some ventilation. B gigantea need strong light and good ventilation, as seedlings are very prone to damp-off.
• TEMPERATURES: adult annual plants are not fussy about temps. I keep some annuals in my greenhouse with the door permanently open in the summer. They seem to take temps down to at least 8 dec C without problems. Hot days are, I think, best, but as long as the light levels are high enough, they seem to manage OK with day temps in the high teens (deg C). B gigantea is a perennial, and can and can take temps as low as just above freezing. I keep most plants in a frost-free greenhouse all year long. I do keep a few plants on a very sunny windowsill in winter as an insurance measure, though. Low light levels and damp can lead to fungus and rot in the winter, though. In climates warmer than the UK, they will probably do well outside, at least in summer.
• WATERING: B gigantea likes to be kept damp. I stand it in a couple of cm of water, but I let the water all evaporate before adding more. If it sits in water for too long, it can rot. In the winter, I keep the substrate merely slightly damp, but I never let it dry out. I like to have a 1/2cm layer of silver sand on top of the normal substrate. This will usually remain bone-dry at all times if sufficiently tall pots are used. I generally sit the annuals in a bit of water, but they can also take quite dry substrate.
• POLLINATION: all except B liniflora and aquatica must be cross-pollinated for seed to be reliably obtained. The anthers need to be teased (a matchstick or suchlike is ideal) in order for pollen to be released. It can then be transferred to the female parts of flowers on another plant
• LOCATION: all are unfussy. B gigantea can be grown on a very sunny windowsill all year round, although it does seem to prefer my greenhouse in the summer. The annuals (especially filifolia, guehoi and rorida) are also unfussy as adults. They are equally happy in a greenhouse or on a very sunny windowsill.
• COMMON REASONS FOR FAILURE WITH THE ANNUALS: I have found the following to be causes of failure: insufficient sunlight; excessively dense substrate (hence my liberal use of perlite); in artificial conditions, plants being kept too close to fluorescent lights (I always keep a layer of glass between the lights and the plants- they can then be as close as you like); insufficient light, warmth and humidity (seedlings only); poor ventilation leading to sudden rot; inbreeding (try to keep a good genetic mix in your collection if space will allow). Note that B aquatica is far more fussy than the others, and requires tropical conditions with strong light and good ventilation- I keep them near a reptile fan in a heated terrarium, even as adults.
I sell spare seed every year on the CPUK forum. I also donate a lot to the British Carnivorous Plant Society’s seedbank (use of which is not restricted to UK-based members).
Cheers,
Greg