It's been a little while since the last post was released here, but then summer's been busy...nevertheless, there are a few groups of carnivores that I have had experience with growing from seed that need to be covered still, and this is the next installment of that series. Today's focus: Byblis, the Rainbow Plants.
A sticky-leaved group of carnivores from Australia and the island of New Guinea, these species are frequently overshadowed by other genera such as Drosera and Pinguicula, though they have their own charm. Those fond of the slender-leaved plants in the "Indica Complex" of sundews or the threadleaves will find a physical similarity in these, as they tend to grow as tall or branching stems of filiform leaves splaying out in all directions. The glandular tentacles are often larger relative to the leaves as well and cover the stems too, resulting in a complete overload of stickiness and refractive droplets that earned them their title of "Rainbow Plant." Most species are annuals and are built to grow quickly, set seed, and die, but two species from Australia's southwestern coast have adapted to be fire-resistant perennial shrubs and are an incredible show when they establish well.
Byblis is also frequently overlooked for two reasons: one, for healthy plants it is nearly required to grow from seed (cuttings frequently fail or result in weak plants for annuals, and are hit-or-miss with perennials), and two, because people hear about the special requirements that the seeds have to get them to germinate; unlike tropical pitcher plants, or most tropical sundews and butterworts, this genus in general is not set to simply have their seeds thrown on wet soil and sprout up with no further trouble. However, the difficulty of the extra steps needed is often somewhat exaggerated and in reality is quite a simple affair so long as you have the necessary items on hand. There are three primary methods used to induce germination and they are, listed in my personal preference from trickiest to most straightforward and reliable: bleach, smokewater, and gibberellic acid treatments.
The first step is to ensure that you have the right soil ready for the species you are working with. Pretty much all of the rainbow plants will grow happily in a 2:1 sand/peat mix, or even sandier, so long as it remains moist. Two species, liniflora and aquatica, are even more tolerant than the rest and will happily grow in just about any wet peat-based soil mix, wet even to the point of that soil being flooded (especially the latter species, which often prefers it that way). Second step: acquire seeds. B. aquatica and liniflora can self-pollinate, the former with some assistance, the rest of the species needing to be cross-pollinated between genetically different plants to produce them. The seeds must also be good quality. They are small, textured blackish seeds that, while large for a carnivorous plant, are also quite fragile and wasy to squish. Any seeds that have cracked shells are not likely to be viable, and larger, plumped out seeds are better than smaller off-shape looking ones.
With good soil and viable seeds ready, next is treating them. Bleach treatment is the method I first used, but it is also the most dangerous and uncertain to work with (not just for the seeds, but for us too; bleach on the hands is caustic and can cause burns). A 10% solution is prepared, and the seeds dropped in to soak, but they must be watched at all times because bleach works to literally eat away at the chemicals and physical coating on the seed exterior, and as such you can watch the black color melt off in a purplish trail. Seeds must be left just until they start to change shades, from black to a deep purple or brown, and immediately removed and washed (depending on the species, this may take as little as a minute to five or so, and exact bleach concentration may vary the time as well). If they are allowed to sit any longer, or not rinsed off, the bleach will eat through to the embryo inside and kill it.
The second method is smokewater treatment. This imitates directly the means by which these plants are stimulated to germinate in the wild: grass fires during the hot dry season produce ash and smoke that embeds chemicals into the soil and water when it rains, these chemicals acting to counter the germination inhibitors in the seed. Smokewater may be done in one of two ways: hardest, is to sow the seeds on the wet soil of the intended pot, cover the pot with a pile of dry grass and leaves, and light it on fire briefly before covering it to snuff the fire out and produce smoke that is allowed to saturate the seeds and pot. Watering the ashes into the soil also helps release the needed chemicals. One must be careful not to let the fire burn too long or be too hot however otherwise the seeds will simply end up cooked, and not enough smoke may not break the inhibitors well enough to work. The other method is to buy something like the "liquid smoke" sold for food prep at stores or specially made "smoke paper" that's already saturated with the chemicals; place a few drops of the former or a piece of the latter into water, and soak the seeds in that water for a day or two (exact timing I've not been able to track down regularly, so this is a method that may need personal testing to see what time and amount works best) before sowing.
The third method, and the one that I rely on as measurements are well-tested and reliable, is to use gibberellic acid. Good quality GA3 is sometimes difficult to pin down, particularly as the small quantities that any one grower needs may not be readily available and packets sold on eBay and similar locations may be expired or diluted, but it is sold by companies that offer lab equipment and chemicals and often tissue culture specialists. As pure as possible and fresh, well-stored compound is best; this is a natural hormone found in plants that promotes both germination and elongation of the stem. The latter is something to be aware of, as treatment with too much GA3 or for too long can result in weak, etiolated plants even under good strong light, so getting the measures right and timing is crucial. First, if you buy powder and not a solution: follow the instructions that the powder comes with to get the right concentration (a good starter solution is 1,000 parts per million, or ppm). Usually this is somewhere around a 100 milligram scoop into roughly a half cup or so of clean, distilled water. GA3 is not readily soluble on its own, so warm water with just a bit of rubbing alcohol in it to start can help, or just leave the solution to dissolve and settle overnight. Then, prepare the right concentration for the seeds: 1,000 ppm is suitable for the perennial two species, but 500 for annuals. The one annual Byblis liniflora is frequently claimed to not actually need any treatment beyond soaking in water, however I have found that it germinates faster and more readily when treated like the other annuals. Soak annual seeds for 24 hours, but soak the perennial seeds in their stronger solution for 4-6 days. If you have extra solution left over after portioning out what's needed to soak the seeds, note that it will break down and become unusable after a couple weeks or so at room temperature, but can remain viable and effective for many months if refrigerated.
No matter which treatment method is used, the next step is to make sure the seeds are sown on soil and watered in, and then wait. Strong light and warm temperatures (they're all either tropical lowlanders or experience very warm summers), as well as good airflow, are all necessary to make sure they germinate quickly and avoid damping off. Generally germination will happen between 2 days and 2 weeks from sowing, though may at times take up to three months. The annuals require regular feeding (tiny insects or insect pieces, or careful application of liquid fertilizer to the leaves) to grow well, and the perennials appreciate it as well though they are often slower overall. Also, they often do well with an appropriate time-release fertilizer pellet buried a couple inches below the soil near their roots, unlike some other carnivores. Again, the GA3 method is the one that I most recommend, but any method described may work with some practice if you can't get ahold of a good source of the hormone. Here at Carlton Carnivores, if there are Byblis seeds listed on the Seed List sales page I also offer small starter vials of 1,000 ppm GA3 solution to help germination as I purchase it in larger quantities and prep stored solutions for long-term use (directly usable for the perennials, and easily diluted to half-strength for annuals).
Hope this article is helpful, and good luck with your seeds!