Although the hard fern is actually quite robust and hardy, it is particularly sensitive to some care mistakes. These can then cause different diseases.
If the nest fern (Asplenium nidus) is given ideal site conditions, the occurrence of diseases and pest infestation can be minimised. Mistakes in care, above all drought and insufficient humidity, weaken the plant and promote the development of diseases.
Observed more frequently in nest ferns:
- scale insects
- Leaflets
- Thrips
- Reproductive Diseases
Pests at a glance
Scales - stubborn and voracious
Scales are sucking insects. The pests are more common on the underside of the leaves and are therefore often not recognizable at first glance. Honeydew on the upper side of the leaves is often an indication of an infestation. This sticky substance is the vermin's excrement.
Scales are well protected under their hard shell. Nevertheless, the room gardener can remove scale insects without using chemical pesticides. If the infestation was detected early, it is quite possible to remove the scale insects manually.
» Tip: Scale insects should not be scraped off with your fingers. It could be females carrying their offspring under the shell. This would then spread to the plant.
The pests can be removed quickly and completely with a sharp knife. Treating scale insects with a cotton swab dipped in alcohol, olive oil or soapy water is a bit more time-consuming.
Leaflets - small and annoying
While aphids tend to avoid the warm, humid environment of nest ferns, aphids are relatively common. The roundworms are only about one millimeter in size and cannot be seen with the naked eye. The transmission takes place via the irrigation water. The pests penetrate the leaves through stomata and feast on the plant sap. This remains for nowunnoticed. In the advanced stage, glassy spots appear on the fern fronds. In the further course it comes to brown discoloration and loss of leaves.
» Tip: To prevent the infestation spreading to other plants, isolate the nest fern.
Targeting the leaflets is difficult. If you react quickly, the infestation can be contained by removing affected fern fronds and using boiled water. Heavily infested plants should be disposed of better.
Thrips - Thunderstorm creatures with a good appetite
Thrips are brown-black insects that are only a few millimeters in size. The narrow wings have black and white stripes. The nickname thrips indicates the frayed wings. The yellowish, translucent thrips larvae have no wings. Thrips are generally not particularly good at flying and therefore mostly crawl. With their proboscis, the pests reach the outer leaf cells, where they feast on the plant sap. First, the apple-green coloring of the fern fronds decreases and the leaves appear yellowish. In the advanced stage, air penetrates the damaged areas and this results in a silvery-white colouration.
Thrips can be eliminated with a shower of soapy water and olive oil. It is particularly important to treat the underside of the leaves, because this is where the pests prefer to be. With predatory mites, the thrips has natural predators. The mites can be purchased and are then positioned directly on the nest fern.
Detecting reproductive diseases
Now and then reproductive diseases can also occur in nest ferns. This causes the spores to rot. A widespread pathogen is the fungus Rhizoctonia solani. The disease can be identified on a wide variety of plant species and is particularly infested in a warm, humid environment.
The fungus can survive in the soil for several years. The infestation goes unnoticed at first and begins to spread from the roots to the other parts of the plant.
» Attention: Peaty substrate promotes the occurrence of diseases. Always disinfect the substrate.
Especially young plants are affected. This leads to rotting of the spores and root rot. The rotting process on the fern fronds is evident from the formation of brownish to reddish spots.
The occurrence of reproductive diseases can be prevented by sterilizing the substrate. Appropriate watering behavior is also onegood preventive measure.
Other care mistakes
The nest fern shines in a rich apple green. If this is not the case, the cause usually lies in faults caused by care errors. A location that is too sunny can rob the fern fronds of their colour. If the leaves dry up from the edges and dark spots appear on the leaves, the nest fern has definitely gotten too much sun.
Brown leaves can also be an indication of incorrect watering behavior. The nest fern does not like to be watered directly over the leaves. A similar pattern of damage is also evident if the location chosen is too drafty. Brown leaf edges indicate a lack of water and low humidity.