Drosophyllum lusitanicum - the uncompromising giants
Drosophyllum lusitanicum is one of the species I love the most. I never get bored of it and keeping it is an ongoing challenge. It is still a thrill six years after I started my first batch of seeds. It was also a success story for me. I started with 25 seeds, got 22 seedlings and kept them for several years. They flowered and scattered seedlings all over the place. During these years I learned a lot about them. I experimented with burning them, feeding them, observed the self sown seedlings landed in different pots with different substrates. I will tell you about all of this, but let's start with some concise germination and growing instructions:
First scarify and soak the seeds in distilled water until they imbibe visibly.
Sow them superficially, widely spaced, on a mixture of perlite and a little coarse sand.
Place them in a warm, bright, sunny position and keep the substrate constantly moist until germination.
Soon after germination, while they are developing their first leaves transfer them to their final pots.
Use big, deep pots - at least 3 L per plant and the same substrate as above with just a handful of peat moss added.
Take extra care not to damage their roots during any stage of their development.
Try to mimic a rainy season during the cooler months and a dry season during the summer.
In summer water the established plants only in the morning and do not let the pots sit in water for extended periods of time. Imagine them getting water from morning coastal fog/dew and water with small amounts. Tall pots help keep the water level low.
Provide as much sunlight as possible.
There are various methods of scarification, but as long as you make possible water to reach the embryo and you don't injure it in the process it will be enough. Using very fine sandpaper or a sharp triangular file is the easiest method for small batches of seeds. Don't touch the pointed end, this is where the radicle will emerge. The embryo is really close to the seed wall there and you can easily injure it and make it uncapable to germinate. Soaking large batches of seeds in concentrated sulfuric acid will also do the trick.
Scarification will ensure quicker and more simultaneous germination. You will still obtain good germination rates without scarification, but over a much longer period, especially in the case of fresh seeds.
Smoke, gibberellic acid or any other stratification is not needed for the Drosophyllum seeds.
Drosophyllums are very different from the other carnivorous plants. First of all they can live in almost any substrate. I had self sown seedlings in pots with non carnivorous plants like Aristolochia, Agave, ornamental grasses and others. Most of them I had to weed out before shipping those other plants to customers, but one that grew in the pot of a stock Aristolochia had more luck. I left it alone. And it grew undisturbed for more than half an year. Eventually it died during the winter, but what killed it was not the composition of the substrate, but the inadequate (for them) watering regimen. I almost uprooted it once while watering and this surely disturbed it, but it was already rough - deep shade, low temperatures, constantly wet feet. Another one, that germinated in a pot of an Agave is still alive today, two years later. In this case too I take care of the Agave, not the Drosophyllum. The big difference is the watering regimen. Others that tried to grow with Sarracenia seedlings drowned soon, some that landed in very deep pots with mature Sarracenia that are never watered from above and the upper layers of the substrate are dry lived happily until hard frosts killed them.
So the substrate I recommend is very sharply drained, mineral in composition and this is done to ease your life. It should contain a good amount of larger particles. Do not use substrate that consists only of equally sized particles of any kind. Adapting the watering to heavier substrate is a pain especially during the late autumn, winter and early spring. Too little oxygen and their roots suffocate. Aside from this you can grow them in almost anything.
About replanting - the best moment to do it is while the plant is very young, soon after germination and the best way to do it is by moving it with the soil around the roots intact without disturbing the roots. The problem with replanting mature plants is that they do not readily regrow roots and even root hairs. They develop their root system very fast at a very early age, claiming as much substrate as they can and then the growth of their roots stops or at least slows down a lot. If you manage to move them without disturbing the roots and with the whole bale of old substrate intact there will be no problem even for a mature plant. However if the plant is already root bound there will be not much benefit either because they do not expand their roots readily into the new volume.
Drosophyllums are very "stiff" plants. They refuse to adapt, regrow roots, overcome heavier damage or fight at all. They either like their place and grow like mad or die. And they die as slow as a cactus with rotten roots. By the time you notice the leaves wilt they are already beyond saving, the root system has died weeks ago. And most likely from suffocation caused by overwatering.
Drosophyllums are very stict in their requirements. About every one of them. Longterm they do not tolerate any shade. They etiolate easily and die soon.Direct sunlight is the best light for them. High quality full spectrum artificial lighting may be an option too, but it has to be comparable to natural light. Drosophyllums can withstand a temperature range from about -2 to +45℃. In my conditions they require the most sun and heat I can give them in the summer. However the situation will be different in Texas for example. When it comes to watering the situation seems to be really tricky. However if you understand that you should think about how to avoid suffocation of the roots and not about the water quantity or quality your life will become easier. Aside from this the time of year plays a major role here - they should be drier during the summer and moister during the cool months. Any other watering pattern will lead to problems. They do not require constantly high air humidity and dislike stagnant air. Generally speaking they are not very good as house plants - much like Sarracenia they prefer lots of sun and fresh air. They should be watered in the morning before the sun shines on them. Mistng them can be done at the same time, but it is not mandatory. They tolerate rain well and are best grown outside. It is best to water them with rain water or reasonably clean tap water - not too hard, no chlorine or fluor or other specific pollutants. Unlike many other carnivorous plants they can grow in alkaline soil (but don't have to), which makes them a little less picky about the water hardiness.
Drosophyllums should be fed much more than any other carnivorous plant. And the older they get, the more you should feed them. I learned this the hard way when I lost my largest 5 years old specimen and realized post factum that I have starved it to death. They don't really show any signs, and that's why I think this is the reason for the sudden Drosophyllum death syndrome that many people are witnessing (apart from overwatering). There is a dedicated article about feeding carnivorous plants here: Feeding and fertilizing carnivorous plants.
In my experience Drosophyllums don't regrow after burning, but I know that others claim otherwise. Out of 8 plants that I burned only one survived. I did it during the winter - February 2015, here is a link to my post on Facebook from back then with photos and some comments. Winter is not when fire can eventually occur in their natural habitat. This maybe played a role so someday I should repeat the experiment in the heat of the summer. The dry leaves that the plants retain as a skirt burn extremely furiously, at very high temperature and very fast. In just a few seconds the fire is over, but the thin stems are cooked, soft like boiled and the bark of the thicker stems gets covered with charcoal. Even on the oldest stems the bark is not thick enough to offer effective protection for the dormant side buds. Drosophyllums do not regrow from roots, there have to be intact buds on the stem in order to regrow. The instant loss of the actively growing aerial parts stresses the roots too much and as I have observed many times they don't overcome such stress easily. Evidence to this is the fact that some of the plants have woken up some buds and grew a little, but the new growth soon died - a sure indicator that the roots were no longer functioning properly.
Edit 20180520: The specimens from my original collection germinated October 2011. Only one of them is still alive and its vigor is declining during the past months so I am not sure that it will live long enough to see its seventh birthday. The rest have died one by one during the past year. Maybe this is the limit of their life span in captivity?
Edit 20180411: I am not aware how old is the oldest specimen ever kept in cultivation, but it seems that Drosophyllums are not very long lived. My oldest plants are almost 7 years old now, however during the last two years their numbers gradually declined and out of two dozens only a couple are still alive and they are declining too. It seems that after 7 years I'll have to start again. Luckily I stored a few thousand seeds and there are enough volunteers so I don't even have to start seeds on purpose.
Edit 20190303: The plant shown on the last photo got stronger again during the summer but the winter took it's toll and it died February 2019 at the age of 8 years and 4 months.
Even if they are so uncompromising they are well worth the effort and I love them!
Now I want to show you some photos of my plants with some further explanations. Enjoy!
See more Drosophyllum photos in the gallery.
Author of the text and photos: Petar Kostov, telopeanursery.com, 20170129. Updated June 2021.