It’s time to get a good understanding of how to grow Dionaea muscipula (Venus fly trap).
As in all relationships, finding the balance to achieve peaceful coexistence is crucial! Well, yes, if it is true that each plant has its particular needs, it is also true that the enthusiast has them as well.
So if we have come here to find out how to grow a carnivorous plant, more specifically, how to grow Dionaea muscipula, let us also try to do so with us in mind. Thinking about us means not overcomplicating life by learning the tricks of the trade that make growing simple!
Lasting relationships are those in which things, after an initial break-in, run smoothly. So it is worth wasting some time right away to figure out how best to recreate the ideal conditions for growing Dionaea muscipula, management in the various seasons, managing our absences, and how to have maximum results with moderate effort.
Dionaea muscipula is a carnivorous plant belonging to the family Droseraceae (related to the genus Drosera) and native to the USA in a small coastal belt located between North and South Carolina. It lives in peat bogs, “flooded” peat plains constantly soaked with rainwater. The almost constant presence of water causes the soil to be anaerobic, or devoid of oxygen.
The absence of oxygen causes the decomposition of organic matter to be anaerobic (a peculiar decomposition, typical of oxygen-deprived environments, in which predominantly bacteria operate that use an energy metabolism to live that exploits other gases, such as nitrogen or sulfur, instead of oxygen).
The decomposition of organic matter in anaerobic mode follows very slow steps lasting millions of years and gradually leads to the production of peat, lignite, and anthracite (what we call coal, one of the most famous fossil fuels).
This explains why we call these particular and delicate ecosystems peat soils. As a result, peat differs from other soil types in several ways:
- It exhibits an acidic pH.
- has a very low nitrogen content (and other easily assimilated compounds).Nearly zero
We can well imagine how in an environment with an extremely low pH and low nutrient content, there are very few plants that are able to proliferate (it is interesting to start from here to better understand the evolution of carnivores). Dionaea muscipula is one of them.
Here, the description of the ecosystem that hosts Dionaea muscipula allows us to understand its cultivation basis in an indirect way. with the difference that knowledge allows us to consciously cultivate them.
Let us summarize the main aspects:
Venus flytrap Care Guide
Full sun all year long ! It is possible to shade slightly in the warmer summer months to avoid excessive temperatures that can stunt the plant’s growth.
Why a full sun?
Energy issues. Capturing the prey (i.e., closing the trap, starting the digestive process, and reopening the trap) requires a lot of energy from the plant. The energy comes indirectly from photosynthesis. So, increased light intensity = increased energy = increased catches!
for habitat-related reasons. In peatlands, the number of plants able to grow is very limited, and these are mainly small shrubs or sporadic trees that can withstand acidic, nutrient-poor soil. A lack of large vegetation means that there is nothing to cast shadows on the plant, shielding it from direct sunlight.
How to water?
3–4 cm of distilled or rainwater is always present in the saucer. Alternatively, all waters that have an extremely low mineral salt content are suitable. For example, all condensation water (air conditioner, dehumidifier) conductivity of the water should have a value of fewer than 50 microsiemens.
Peatlands are ecosystems with an impermeable, mostly clay bottom, which does not allow rainwater to penetrate the lower layers. The result is permanently waterlogged soil that results from the condensation of atmospheric water vapor, which is naturally devoid of mineral salts.
Mineral salts, on the other hand, are commonly found in fresh water and in our aquifers and result from the dissolving of limestones that make up rocks and go into the waters of rivers and lakes. Dionaea muscipula has adapted to grow in an environment devoid of mineral salts derived from water, particularly carbonates that would, in the long run, raise the pH of the substrate, irreparably damaging the plant.
Dionaea likes stagnant water. 3–4 cm of distilled water in a container, even in the winter, even if it freezes. This is to faithfully imitate the naturally soupy environment in which they live.
50% pure sphagnum peat / 50% perlite
Dionaea does not tolerate nutrients. We avoid pH-neutral or nitrogen-amended peats often found in acidophilic potting soils. Peat must be pure.
Perlite is an inert substrate that helps aerate the substrate. In nature, there is obviously none, but forced cultivation in small volumes (our pots) requires adaptation to increase the shelf life of the constantly wet substrate. CAUTION: Do not breathe in unprotected perlite dust, moisturize it properly before handling it, it is a very fine dust and harmful to our lungs!!!
What to do in winter?
Outdoor plant. outside even during the coldest months!
It evolved to grow in a coastal area between North and South Carolina. So in a temperate climate with hot summers and cold winters, It also tolerates subzero temperatures for extended periods if, during the day, the substrate can thaw and the plant can absorb water properly.
What happens during the winter?
In late fall, the aerial part of the plant begins to blacken and eventually dry out. Dionaea actually conserves energy in an underground stem called the rhizome, which is white in color, and lets most of the aerial part die as the cold weather arrives.
Don’t be concerned.
This is normal. The plant is doing well and should be hydrated with a few inches of distilled water in the saucer as usual, in the same outdoor summer location. In spring, as temperatures rise and light hours increase, the aerial part will sprout again and the plant will begin to vegetate again.
What to do in spring?
In spring, temperatures increase, as do the hours of available light. These stimuli are perceived by the plant as the beginning of a new growing season.
Dionaea’s awakening is characterized by flower growth. If you are not interested in its pollination (see link), I recommend severing it at a height of 2–3 cm from the base with a common pair of scissors. By severing the flower, all energy will be focused on leaf production, which can then develop to its full potential.
Pests and Diseases
Aphids are variable-colored stinging insects (usually white or green), a few mm large, visible to the naked eye, and easily eradicated. They sting and suck plant sap, causing mainly leaf deformities and small galls.
The saliva of these parasites produces auxin-like substances. Auxins are plant hormones that, along with others, control the plant cell cycle. Disruption of the hormonal balance causes the plant to produce galls, which are small clusters of undifferentiated cells (tumors) that appear as leaf bulges.
Aphids can be removed manually or easily eliminated with organic pyrethrum-based aphicidal products. Repeat the initial treatment after 10 days to also eliminate any new hatchlings from the eggs laid initially.
Mites: The most feared pest of Dionaea muscipula is the well-known red spider mite. It is an arachnid (not an insect) of very small size (0.5 mm for females and even less for males) with stinging mouthparts. It stings the leaves of our plants to suck up sap and feed. The primary symptoms of red spider mites are leaf discoloration and leaf wilting or browning that occurs much faster than normal, often when it should not.
Why is it dangerous?
Its small size makes it difficult to detect, and its symptoms can be mistaken for normal leaf browning due to excessive heat or the arrival of cold weather and vegetative rest.
However, an infestation of red spider mites can lead to tremendous stress on the plant, which, with the arrival of heat, tends to almost completely halt the production of new leaves and completely darken old ones. Many growers report almost complete stunting of growth and a tendency for the plant to shrink until it almost disappears.
How do I get rid of it?
For minor infestations, a contact acaricide insecticide is used, followed by a systemic acaricide for major relapsing infestations. If neglected, it can become really difficult to eradicate this pest.
It rarely infects Dionaea. It usually occurs when nearby Sarracenia are attacked by a mealybug. In this case, manual removal of the easily recognizable pests can be done first, and only then, if they reoccur, with systemic cochineal treatments during the growing season and/or mineral oil to get rid of the eggs during the winter.
Light shading is recommended during the warmer months to prevent temperatures from rising too high. Excessive heat can cause Dionaea muscipula to become stressed and stop growing (especially when grown in small greenhouses in full sun during the summer).
If the plants have been in the same substrate for more than one season and the flower has not been cut in early spring, the symptoms of this summer “stunting” are even more pronounced.
What do we recommend doing to avoid heat stress?
1) Provide shade in the hottest months with the aim of lowering the temperature.
2) Repot our Dionaea every year, around the end of February, in the fresh substrate. They prefer slightly larger pots, 10-12 cm in diameter if kept on the same substrate for 2-3 years.
3) Receiving a flower in the spring Flowering, especially when associated with flower pollination, leads to significant energy consumption.
Tips for Holidays
What if you need to leave your carnivorous plants for some days?
Managing our Dionaea when we are on vacation is easier than expected. The fact that they not only tolerate but even love water stagnation makes it possible to use the raft system.
Using a suitably sized piece of expanded polystyrene or any other floating support, a floating platform can be made for our pot.
1) We drill a hole in the center of our floating raft so that the jar can be placed there. The holes in the bottom of the jar must protrude from the bottom surface of the raft.
2) We choose a bucket or container large enough to hold the water needed to cover the plant’s water needs for as long as we are away (be careful to also consider evaporation and not just water absorption by the plant).
3) We place the raft with the pot in the container filled with water. Make sure the buoyancy is stable!
This way the raft will adapt to the water level, which will gradually decrease, keeping the peat moist and the aerial part dry!
In this article, we have tried to talk about all the main aspects of cultivation, not in a schematic and generalist way, but by trying to follow a logical thread that starts from the natural habitat and aims to make the needs of the plant compatible with those of humans (including vacations). For all aspects not related to cultivation, including the mechanism of prey attraction and capture, evolution, and curiosities inherent to Dionaea muscipula, visit the appropriate article here: