Around 70 people tirelessly look after thousands of different plant species in the Botanischer Garten (botanical garden) in Munich. And they are not all professional gardeners. Christine Bernhauser, for example, was initially a banker before she fell in love with carnivorous plants. Now she works in the botanical garden and makes sure they are happy and thriving.
It is easy to recognise that the woman standing next to the pavilions is Christine Bernhauser. She is wearing outdoor trousers and a T-shirt with a picture of a Venus flytrap. Bernhauser looks like a person who likes to be outside. In Munich’s botanical garden, she is known as “the lady with the carnivorous plants”. She tries to sense their needs and makes sure they thrive.
Bernhauser shows us the pavilions in which her plants live. Small houses with a concrete base with a white wooden structure framing large glass panels. Venus flytraps grow in every corner, like the ones on Bernauser’s T-shirt. The trap leaves, red on the inside, green on the outside, are only the size of a coin.
The Venus flytrap – is this the carnivorous plant most people know?
Yes, many know them from films. But plants so big that you fall in and get digested don't exist in real life, of course. Nevertheless, many people are fascinated by Venus flytraps. I ask the children not to tease the plants too often. The leaf can only close a few times before it dies, and that costs the plant a lot of energy.
How does the mechanism work?
The trap leaves have several tactile hairs. When an insect touches them once, nothing happens. The trap only snaps shut the second time. The long bristles at the edge of the leaves interlock so that the insects are caught.
What fascinates you about carnivorous plants?
I think nature has come up with something very clever. There are so many different plants with different ways of catching insects. And they look very different: For example, there are the colourful tubular trumpet pitchers, the fork-leaved sundews with their glittering tentacles. I believe that these plants have a life of their own, a personality.
Christine Bernhauser did not always work as a gardener. Until 16 years ago, she was a foreign exchange trader at a bank and was often insanely stressed. Then she met her current partner, who was passionate about carnivorous plants and moved in with her "with his swamp", as Bernhauser puts it. Bernhauser took a sabbatical, spent a lot of time in the garden, discovered her love of nature – and her passion for carnivorous plants. After a short internship in the nursery, she knew: “This is what I want to do.”
Now a fly sits on a trumpet pitcher that looks like a tall, narrow funnel with red lines running through the white top part. “Oh, that’s dangerous”, Bernhauser says.
Is the fly about to fall in there?
It’s pretty close. The insects land on the edge and then often fall down the tube. When they try to free themselves, they slide down even deeper. In autumn, the tube-shaped traps are sometimes three-quarters full of insects.
Do you occasionally feel sorry for them?
I also love animals, so sometimes I have mixed feelings. Once or twice I have freed an insect that I heard buzzing in the tube of a trumpet pitcher. In this process I was once stung by a bee – because I acted stupidly when I tried to resuce it.
What other ways have the plants developed to catch insects?
Some have tentacles that are covered with slime. The insects than simply get stuck to them. Some can also move their tentacles towards the prey and completely enclose the insects. I also find the mechanism of the suction trap ingenious: It works with negative pressure. When an insect approaches, a kind of small door opens and the plant sucks in the insect.
To make sure the plants in the pavilions thrive optimally, Bernhauser tries to identify their needs. When it's not too hot, she opens the awnings so that the plants get enough light. On hotter days, she provides shade. In a greenhouse that is not accessible to the public, she meticulously cultivates Roridula shrubs.
How do you do that?
First, I had to pollinate the plant. Normally, only the buzzing of the pollinator insect triggers the pollen to fall out of the plant. I simulated that with a tuning fork. Then I collected the pollen and applied it to the stigma with a brush. After pollination, the plant develops the seeds. These I collected with empty tea bags, which I hung in the plant.
And then you planted the seeds?
Exactly, but that's not all. In areas where Roridula shrubs are native, there are regular bush fires. The seeds need that to germinate. So, I lit a fire and exposed the seeds to the smoke. Raising a plant from pollination to sowing – that’s a success story and sheer pleasure. When we do something like this, we also inform other botanical gardens and ask them if they would like to have some seeds, too.
Why are the plants called “Wanzenpflanzen” – bug plants in German?
There is a certain species of bug that usually lives on the plant. The plant catches insects with its sticky leaves. Then the bugs eat the insects and the plant feeds on the bugs’ excretions. We don't have bugs here. But the plants can survive quite well without them. However, they cannot independently digest the flies that stick to the plant all over here.
Another plant in the greenhouse has funnels shaped like little toilet bowls. It is called Nepenthes jamban. Jamban is the Indonesian word for toilet. Outside, a little way from the greenhouse, are dozens of Venus flytraps and trumpet pitchers in flowerpots. In one of the trumpet pitchers, an insect is humming in distress. "We spend a lot of time moving them in and out," says Bernhauser. "The plants are more robust when they are outside in the summer."
What has made you particularly happy recently in your work here?
When a plant flowers that has not flowered before, that is a personal success story for me. In my 13 years here, I have not seen the Brocchinia reducta flower. Now a blossom is appearing, and when I saw that, I really let out a cry of joy.
When you're not busy with your carnivorous plants – what other areas do you particularly like here?
At the moment, I'm a bit involved with birds, so I like to go to the forest of the botanical garden during my breaks. There are old trees, an incredible number of birds and benches to sit on. In summer, I like going to the crop plant section and looking at the herbs and vegetables. The ornamental courtyard at the entrance blooms beautifully in late summer. I'm really proud of my position here, and in retrospect it's a huge stroke of luck that my friend and his swamp moved in with me.