Each leaf is host to a number of glands that produces a mucus which lures, traps and digests unsuspecting insects. In Victorian times, the butterwort was commonly used as a natural means of controlling whitefly, and I have found them to be of incredible benefit in keeping fungus gnat invasions at bay.
My journey with Pinguicula started in 2010 upon the receipt of Beatrice, a Pinguicula 'Weser', and although my enthusiasm for carnivorous plants was started through the world-renown Venus fly trap, butterworts will always be my passion and focus in the carnivorous plant universe. Years of research, joyful successes and innumerable failures have left me wanting to share my experiences, and so I have compiled various guides for your viewing pleasure.
Pinguicula are typically divided into different groups depending on their general care and winter needs, to that end I've divided my own care guides into three main sections, which you will find below; each section contains care instructions and species lists. On this page you will also find topics that pertain to any of the Pinguicula groups, such as identifying problems and diseases; simply click the topic title to expand on it, and click it a second time to hide it. If you are ever in need of further assistance, or wish to simply explore the carnivorous plant world more in detail, I highly recommend the Flytrapcare.com website and associated forums; you can find me as Grey.
(Image courtesy of dimitar @ Flytrapcare.com)
This group of Pinguicula is subject to cold, ometimes harsh, winters and so many species develop hibernacula in the winter to keep them safe. Beginner species include: Pinguicula grandiflora. Countries of origin include Turkey, France and Greece.
Mexican Pinguicula have two growth phases: summer and winter (or carnivorous and succulent). They are by far the easiest group of Pinguicula to care for and there are many robust hybrids available. Beginner species include: Pinguicula moranensis. Countries of origin include Mexico and Central America.
(Image courtesy of parker679 @ Flytrapcare.com)
Subjected to somewhat mild winters, warm temperate Pinguicula have no natural defence against snow and frost. Beginner species include Pinguicula lusitanica. Countries of origin include Spain, the United States of America and the United Kingdom.
Browning heart disease (BHD) is a swift striking, often deadly plant disease that is caused by two factors: an unusually high population of female nematodes and a naturally occurring fungus known as Fusarium. Ordinarily, Fusarium would not harm a healthy Pinguicula but if female nematode populations are high enough they start to feed on the roots of the plants, which gives the fungus an opportunity to take hold and destroy the plant from the inside out. When populations are at normal levels, nematodes are believed to be of benefit to plants.
You can identify if one of your Pinguicula might have BHD by looking closely at its leaves; if affected they will usually be dull and dark green, lacking mucus and appear pitted (as though collapsing in on themselves) or wrinkled. If you uproot your plant you will likely notice that previously white, healthy roots are brown, black or have withered away altogether; the base of the plant may have turned black and the centre of the rosette (the heart of the plant where everything grows from) will eventually turn brown and shrivel or become “crispy”. The affected plant may have already died but retained green leaf tips despite that.
It's important to assess each of these symptoms and consider whether or not it is the growing environment that is to blame rather than BHD; dark and dull green leaves, for example, may be a sign of lack of lighting and brown roots could be a sign of rot. The two key symptoms here are the pitting of the leaves and the rosette drying out – although by the time the latter becomes noticeable it's usually too late to do anything.
Preventing this disease is easier than curing it and can be achieved by removing excess water from water trays as soon as possible (as Fusarium spores can travel through water), keeping plants potted individually and re-potting them regularly (once every one to two years) in an airy soil mix (in the case of Mexican Pinguicula in particular), avoiding over-watering, keeping air circulation at a maximum and carefully top watering during particularly warm weather. You don't need to micro-manage your plants, just use simple common sense. With regards to Mexican Pinguicula (which are particularly delicate when it comes to this disease), you can allow the plants to dry out a little between each watering cycle to reduce the chances of them having problems – but this is a good common practice anyway.
Treating BHD can be a bit tricky as many fungicides can harm Pinguicula, but if the plant is looking as though it will succumb to the disease anyway it's probably worth the risk. Hydrogen Peroxide (H202), Benlate, Oxquinoline Potassium Sulfate are all recommended in the treatment of BHD, but please be extremely careful and do research into each of these before you use them to avoid risks to your own health.
Some people have reported success in defeating browning heart disease in Mexican Pinguicula by allowing their plants to dry out for lengths of time; this may spur the plants on to enter their succulent growth state, but this shouldn't harm the plants in the long term. You may find that removing affected leaves and other plant matter, re-potting the plants and then attempting the “dry-out” method resolves any issues you have. Another alternative for Mexican Pinguicula is planting them in a purely mineral-based media, but you can read more about this in the Mexican Pinguicula care guide.
When given the right conditions for growth (light, water, soil, etc.) Pinguicula tend to thrive and experience few issues in the long run, however as with all living things problems can be encountered and so it's important to know what those problems are and, more importantly, how to tackle (or prevent) them. Please note that it can and does take time for a plant to recover if it has received treatment for any of the following, so if your plant's overall health declines for a brief period (or it stops producing mucus), this may be a normal part of the recovery process.
Root & Rosette Rot
Most commonly experienced in Mexican Pinguicula species & hybrids (though this does not mean that cold or warm temperate Pinguicula are immune), rot in its various forms is not an uncommon problem for those new to keeping these plants; you can tell a plant is experiencing rot if it has brown, mushy roots or its heart (the “rosette”) is becoming soft, brown and squishy. You might be able to identify rot in its early stages by observing your plant's growth: is it growing abnormally slowly for the time of year? Is the leaf growth looking limp?
The keys to avoiding rot are simple: make sure your plant is receiving the right level of moisture for its species (consider that Mexican Pinguicula typically do not need as much water as cold or warm temperate species, as an example) and the time of year, also ensure that your growing medium has some form of product in it that allows oxygen to flow, such as peat or perlite. Re-potting your plants once every one to two years will also help, when the species allows, as soil compacts over time and this will reduce the oxygen flow through the container.
If you believe your plant is experiencing mild rot, the best course of action is to reduce the watering and see if that helps; if it doesn't, or you find your plant has a severe case of rot (brown, mushy parts), you can carefully uproot the plant, cut away the rotten bits and re-pot it in fresh soil. If you find you continue to experience issues, it might be worth looking at the soil mixture you use and adjust it accordingly to make sure it has something in it to allow air to flow freely around the roots of the plants in particular.
Mould & Fungus
Mould and fungus can come about through a combination of factors: temperature, moisture, humidity and lack of air circulation; a particularly warm (or cold) environment combined with high humidity, lots of moisture and very little air circulation is ideal for mould and fungus to take hold. Ordinarily you can easily remove mould from the surface of the soil using something such as a spoon or piece of kitchen towel, but if this keeps coming back then you need to look at your growing environment and assess whether or not you need to change anything – it's a bit of a balancing act, but you don't need to micro-manage it.
Please be aware that there are lots of naturally occurring fungi in peat, and these in and of themselves shouldn't be harmful to your plants if they are healthy and their conditions stable. Please also be aware that most Pinguicula seem to be quite sensitive to certain kinds of fungicides, so it's important to do your research before attempting to use any chemical products.
Leaf Issues & Death: Identifying the Causes
It is completely normal for old leaves to dry out, shrivel and die as new ones grow to replace them, these leaves will ordinarily be the ones that are closest to the surface of the soil. If your plants are kept in the right conditions, continue to put out new growth and have healthy roots, minor leaf loss (referring to older leaves) or damage isn't ordinarily a major cause for concern, but it is definitely important to run a mental check list if you spot unusual growth or damage, particularly in younger leaves, and assess what the potential cause(s) might be.
(Before we continue I'd like to emphasize that Pinguicula, as a whole, are very robust and you really shouldn't need to micro-manage your environment except in the most extreme climates; granted, some species can be a bit tricky but in general it is simple to set up the right environment for your particular species.)
The first thing to consider is what kind of damage you are seeing. Are leaves shrivelling and dying? Are they moist and mushy? Do they have holes in them or brown spots/splotches? Are there abnormal leaf shapes or apparent “cuts” in the leaves? A lot of the time it seems that the environment in which plants is kept is responsible for these issues; too much humidity and moisture with lack of air circulation, for example, can cause brown patches on lower leaves, and a lack of sunlight may be responsible for abnormally shaped leaves as well as dark green, floppy leaves in the case of Mexican Pinguicula. Ultimately, the first thing you need to do when trying to determine the cause of your leaf issues or loss is look at your growing environment, because you may find that a minor change in any of your conditions may benefit your plants in the long run.
Another possible cause for leaf damage is scorching, which happens when the leaves of your plants are exposed to water, with droplets still remaining on the leaves themselves, then exposed to direct sunlight; this can cause burning which damages the leaf; in extreme cases the leaf can die off. This is easily avoidable by watering your plants from the bottom using a tray or dish.
Peat is amazing – it is highly water retentive, contains a natural acidity and lack of nutrients which is why it is considered one of the best, if not the best, base for many carnivorous plant soil mixes. Unfortunately this immensely useful resource is gathered from areas with a rich diversity of bizarre and wonderful flora and fauna, unique creations that are under strain because of the unsustainable nature of most peat mining operations. Not all of these operations are the same, and you can buy peat that has been dredged from rivers and water reservoirs which is more gentle on the environment than mining, but sometimes it is good to look at other alternatives that enable us to do our part to steward our planet. So what're we going to look at? Coconut what? Coconut peat!
Coco peat, also known as coco coir, is a natural fibre extracted from the husk of a coconut; coir has all manners of uses ranging from substrate for invertebrates and reptiles to the crafting of door mats, mattresses and ropes – and it has, with increasing finesse, started being looked into as the environmental “saint” for many in the horticultural and agricultural industries.
Coco peat is devoid of nutrients, bacteria and fungal spores, and compared to sphagnum peat is easier to acquire and can be much, much cheaper as it is usually sold in dehydrated bricks which can then be soaked in water and left to double or even triple in volume. In various growing comparisons coco peat appeared to settle around the roots of Venus fly traps better than sphagnum peat (this could be due to its soft and loose nature) and when mixed with silica sand has been said to be of equal or greater quality than sphagnum peat when used as a potting media.
Some of the husk (or pith) used in coco peat is recycled matter that may have otherwise been thrown away and left to decompose (which can take up to and over twenty years), and therefore wasted. In general, coco peat offers all that sphagnum peat does but without the environmental impact that peat mining incurs.
The one major downside with coco husk/peat/coir/pith is that it has to be processed before it can be sold in its dehydrated bricks, and this processing usually involves using vast amounts of sea water which will leave salt and other dissolved minerals in the coco peat itself. You have to wash it thoroughly (using pure waterr) before it is safe to use with carnivorous plants. How can you do this? Thankfully Steve from Flytrapcare.com has given me permission to share his method with you. Any reference to pure water, TDS and PPM can be read about in the related article on this page.
“ Ignore any manufacturers' or retailers' claims that their coir is low in mineral salts or soluble material. While the coir may not damage vegetable or flower gardens if used as a minor ingredient mixed with a lot of soil, it will almost certainly damage or kill plants when used as a primary ingredient in a soil mix, and this is especially true with plants that are sensitive to dissolved solids such as Venus Flytraps and other carnivorous plants. Much of the coir I have bought and used had an initial TDS (total dissolved solids) of over 1000 parts per million in the drained water from just the first soak of many! (under 50 parts per million is the suggested amount for carnivorous plants).
To desalinate coir, it can be soaked for 8-12 hours at a time, then drained and soaked with new distilled or other pure water, perhaps in 8-10 soak/drain cycles. A cheap TDS meter can be bought and used to determine when the drained water is consistently under 50 parts per million in total dissolved solids. At that time, the coir can be dried and stored, and the fluffy, dry coir can then be used as an ingredient in growing mediums mixed with other materials such as perlite and silica sand.
In the method I use, I put the rehydrated, expanded coir (it comes in a compressed brick that needs to be soaked for its initial expansion to usual volume) in a bucket and then barely cover it with distilled or rain water. That is to say, I pour only enough water to reach the top surface of the coir, then allow it to soak for at least 8 hours. I found that the maximum amount of soluble material can be extracted by the water in that amount of time, and soaking a greater amount than 8-10 hours did not produce a much different result, but soaking for less time than 8 hours did not extract the maximum amount of soluble material for the amount of water used.
My usual coir growing mix so far, developed by experimentation and with an aim to mimic my favorite sphagnum-peat-moss based mix in water retentiveness and drying time between waterings is 12 parts dry, fluffy coir by volume to 5 parts silica sand. If I were to use perlite instead of silica sand, I would probably initially adjust the mix to include more perlite by volume: either 12 parts coir and 6 parts perlite, or 10 parts coir to 5 parts perlite.”
Here is a brief glossary that contains some of the phrases and terminology used throughout the articles and guides in this section of the site.
Clumping: a term used to describe a natural propagation method in which a plant produces new plantlets at its base, which grow in a “clump”.
Gemmae: tiny vegetative bulbs (similar to hibernacula) that can be planted like seeds; usually produced in late winter/early spring by some species of cold temperate Pinguicula.
Growing media: a combination of soil and other products (such as perlite) used to grow plants in.
Hibernacula: a vegetative bulb that enables some species of Pinguicula to survive the colds of winter.
Parts per million (PPM): the measurement used to describe the amount of dissolved mineral content within a body or water.
Photoperiod: a period of time, within 24 hours, where an animal or plant is exposed to sunlight.
Propagate (propagation): the act of increasing a living organism's population whether naturally or artificially.
Pure water: water that is extremely low in or devoid of dissolved mineral content.
Stratify (stratification): the preparation of seeds before germination
Terrarium: an enclosed and presumably “self-sustaining” environment that houses plants; often created through the use of a fish tank or glass bowl.
Each Pinguicula care guide mentions the importance of using water that is low in dissolved mineral content (which is also known as “pure water”), but they do not explain why this is important or where to acquire this resource. The unfortunate truth is that plain tap water simply isn't suitable for most carnivorous plants because it often contains large quantities of dissolved minerals that our plants simply wouldn't encounter in their natural environment; consistent exposure to high levels of minerals and nutrients can cause our plants damage in the long term and even kill them simply because their roots were not designed to handle processed or high mineral water (although a single watering with tap water in an emergency is fine). Thankfully there are alternatives available which are as follows:
I suppose this makes sense, right?? Rainwater is the cheapest safe water you can use for your carnivorous plants; collecting it from the open sky in a bucket or tray is usually better than gathering run-off from a gutter as gutters can collect all sorts that can leech into the water, which could be harmful in the long run for your carnivorous plants.
Reverse Osmosis (RO) Water
RO water is usually tap water that has been run through a multi-stage filtering process that removes all mineral content. It is usually available for mere pence (or cents) per gallon from aquatics stores, although some chain pet shops do sell it in their fish department as well. You can buy personal RO units that attach to your tap, which may be cheaper in the long-term if you have a large number of plants, although these do cost quite a bit in the short run.
These two types of water and produced differently but are equally devoid of mineral content and therefore safe to use with your carnivorous plants. They can usually be purchased in 5 or 25 litre vats but are, unfortunately, rather expensive. This water may also be advertised for use in car batteries and irons.
Please be aware that boiled tap water will not suffice and will, instead, increase the mineral content of the water as the steam escapes due to the decrease in water volume; distilled water is basically the steam that escapes from boiled water.
The Science-y Bits<
It is entirely possible to test your own water source to see if it's suitable for use with your carnivorous plants; this can be achieved by using a Total Dissolved Solids (TDS) meter, which can usually be bought online for between £10-£20 not including postage. TDS meters come in a variety of sizes and styles, most have two prongs which sit in the water, but as long as it gives you an accurate reading in parts per million (PPM), it doesn't matter what style you get. Please be aware that the instructions for each brand may vary slightly.
As mentioned briefly, TDS meters give you a reading in parts per million, this basically tells you how much dissolved content is in the water: the higher the number, the higher the mineral content. For carnivorous plants, it's usually advised that the water you use have less than 50 PPM.
The dissolved mineral content in each body of water around the world will vary, sometimes it will also vary at different times of the year or before/after treatment to make it suitable for human consumption; because of this it is important that you regularly test your water source, particularly if using low PPM tap water.