Ferns are unproblematic contemporaries in many respects. They are easy to plant, spread quietly without much effort, and form beautiful fronds. Caution is advised, however, because some ferns are very poisonous. Here you can find out whether yours is one of them.

In a nutshell

  • Fern is one of the oldest plants in the world
  • all fern species are considered to be slightly poisonous
  • Poisoning usually only possible with oversized quantities
  • three ferns very poisonous
  • Most Poisonous Fern: Bracken

Fern species in Germany

Ferns generally like it shady and damp, which is why they are often found in forests or along streams. Due to its particularly beautiful leaf fronds, the fern is also often planted in the garden or in the house as an ornamental plant. There are 12,000 species of ferns worldwide, around 170 of them in Europe. The most common ferns are

  • Stag's Tongue Fern (Phyllitis scolopendrium)
  • Brown-stemmed spleenwort (Asplenium trichomanes)
  • Lady Fern (Athyrium filix-femina)
  • Male fern (Dryopteris filix-mas)
Stag's Tongue Fern (Phyllitis scolopendrium), Spleenwort (Asplenium trichomanes), Lady Fern (Athyrium filix-femina) (from left to right)

Ferns are also becoming increasingly popular as ornamental plants for the home. In contrast to domestic ferns, however, indoor ferns require warmth and quite a lot of light. Popular indoor ferns include:

  • Sword Fern (Nephrolepis)
  • Maidenhair Fern (Adiantum capillus-veneris)
  • Antler fern (Platycerium bifurcatum)
  • Polypodium vulgare
  • Nest fern (Asplenium nidus)
Staghorn Fern (Platycerium bifurcatum) & Sword Fern (Nephrolepis)

Toxicity classification

Most ferns are classified as mildly toxic. No species is completely non-toxic. However, usually such a large amount has to be eaten in order to suffer from poisoning that it seems almost impossible. Symptoms of mild fern poisoning would be diarrhea and vomiting. There are also ferns that contain a high concentration of poison and are therefore very dangerous for humans. Inhaling the spores is sometimes enough to cause poisoning. Garden owners should therefore know their ferns well and plant them with care.

Pet owners in particular should make sure that the plant with its magnificent foliage is not eaten by animals. Both grazing animals and pets can become ill after eating poisonous fern. Symptoms of the disease that could lead to death include the following:

  • (bloody) vomiting
  • (bloody) diarrhea
  • stomach pain
  • signs of paralysis
  • Increased saliva production
  • Tremble
  • cramps
  • difficulty breathing

Eating poisonous ferns can also cause life-threatening symptoms in children. Then there are similar symptoms as in animals.

Three highly poisonous fern species

Bracken (Pteridium aquilinum)

The bracken fern plant as a whole is highly toxic. This makes the bracken the most poisonous fern in Germany. It contains toxins such as hydrocyanic glycosides, thiaminase and pteridine. Even when drying, these substances are not degraded. The enzyme thiaminase destroys the vitamin B1 in the organism when it is absorbed and can thus cause disturbances in the movement process. Furthermore, poisoning with bracken fern promotes the development of tumors as well as esophageal and gastric carcinomas. Poisoning can be triggered by skin contact with spores or leaves. You should therefore wear gloves when planting and caring for them.

  • Location: semi-shady to shady
  • Soil: Fresh to moderately moist, gravelly to sandy
  • Planting time: spring
  • Growth height: 1.5 to 2 meters
  • Occurrence: Forests, meadows, pastures
  • Leaves: Green, long-stalked triangular fronds, three to four times pinnate, slightly hairy
  • Hardiness: hardy
  • Toxic: Entire plant highly toxic to humans, pets, and grazing animals

Notice: Cultivate the bracken with appropriate protective measures. If you are a pet owner or have children living with you, you should limit the plant with a protective fence.

Male fern (Dryopteris filix-mas)

The real male fern is also known as the common male fern or male fern. It got its name from its earlier use as a wormer in humans. Its ingredients, such as acylphloroglucinols and tannins, caused side effects even then that could even lead to death. Symptoms of the poisoning to date are:

  • nausea
  • diarrhea
  • visual disturbances
  • blindness
  • a headache
  • liver damage
  • fainting spells
  • cardiac insufficiency
  • damage to the airways

The external application of the male fern is also dispensed with today.

This fern species is just as dangerous for pets and livestock. In the past, it was used as a wormer for animals, but the danger that can lead to death in animals is now well known.

  • Location: semi-shady to shady
  • Soil: moderately dry to fresh, sandy to loamy
  • Planting time: spring
  • Growth height: 60 to 100 centimeters
  • Leaves: Short, pointed and bipinnate leaves on fronds up to 120 cm long, dark green above, light green below
  • Hardiness: hardy
  • Toxic: Whole plant is toxic to humans, pets, and grazing animals

Japanese cycad (Cycas revoluta)

The Japanese cycad is also known as the sago palm fern. The seed and roots contain the glycoside cycasin, which can cause liver damage, bloody diarrhea, and neurogenic effects in humans. The fern plant should also be planted out of the reach of animals. The fern is just as toxic to them as it is to humans. The fern causes disorders in the gastrointestinal tract and the liver. Animal experiments with rodents have even shown a carcinogenic effect.

  • Location: shady to semi-shady
  • Soil: fresh to moderately moist, sandy to loamy
  • Growth height: 2 to 3 meters
  • Leaves: Dark green, leathery and simply pinnate fronds up to two meters long
  • Hardiness: no - sensitive to frost

frequently asked Questions

What to do in case of poisoning?

Call 911 and your local poison control center. The staff there will tell you what you can or should do.

What do I have to consider when dealing with poisonous fern?

Wear gloves and long-sleeved clothing when planting, cutting or tending. After working with the plant, clean your hands properly and clean used clothing separately.

How toxic is fern to pets?

The above three very poisonous ferns are also very dangerous for pets and grazing animals. Other types of fern are more toxic to smaller pets than to humans. However, animals often have a sense of which plant they should not eat. In the event of poisoning, call animal emergency services or your veterinarian immediately.

Category:

Garden plants