Exotic, robust and decorative – the Antarctic tree fern, which originally comes from Tasmania, the eastern Australian mountain forests and some sub-Antarctic islands, is becoming more and more important as a container or outdoor plant in domestic gardens. The tree fern (Cyatheales) presents a thick trunk and numerous green fronds, which are decorative both in the bucket and in the field. The plant is characterized by a rather slow growth, which does not exceed an increase of 5 cm per year. Overall, the trunk reaches a maximum height of four meters, with the crown having up to 60 fronds. Properly cared for and, above all, optimally wintered, both passionate hobby gardeners and laypeople enjoy the plant, which brings an exotic flair to the garden.
Table of Contents
Suitable location and optimal soil
The Antarctic tree fern is considered to be quite resilient and thrives in both shade and partial shade. However, intense sunlight or a location in the sun can damage the plant. There is a slight risk that the leaves will burn and turn brown. The ideal location offers additional protection from the influence of strong winds, which can injure the plant. The humidity also plays a role when choosing a suitable location. For example, particularly humid areas in the garden, which also offer high humidity, are advantageous for cultivating the tree fern. The plant thrives outdoors as well as in the tub on the balcony or in the winter garden. If the plant is cultivated in the winter garden, it must be ensured that that not too much heat reaches the location of the tree fern during the summer months. In order to find a suitable place in the field, an orientation can be given to
be useful for certain types of plants.
Areas on the house facade or on walls are ideal locations. Within the chosen area in the garden, the plant can be cultivated from spring until the onset of the first light frost.
A change of location or optimal winter protection is then necessary.
The use of the substrate also plays a role in ensuring optimal growth. The earth should have certain characteristics:
- fumes
- slightly sour
- poor in lime
- loosened up
Normal potting soil is particularly suitable for successful cultivation, but also rhododendron soil. Bark humus, to which coarse-grained proportions of expanded clay, gravel or lava gravel are added, is suitable as a self-made mixture. This composition allows for better ventilation of the plant.
Watering and fertilizing – caring for the plant
The Antarctic tree fern needs adequate irrigation for healthy development. Overall, the plant must never dry out completely; Watering must therefore be carried out regularly, especially in very dry weather conditions. Not only should the soil in which the plant is planted, but also the leaves and the trunk should always be kept well moist. Especially in older specimens, the root network needs sufficient water. From a temperature of 30 ° C, watering must even take place daily. If the humidity is also low, it has proven useful to also provide the fronds with moisture. For this purpose, the irrigation water is applied to the appropriate parts of the plant with the help of a spray bottle.
Even if the plant needs a lot of liquid, on the other hand the formation of waterlogging should be avoided. Persistent moistening of the roots by standing water can cause various diseases, for example root rot. Therefore, in the case of potted plants, water drainage should be made possible in the bottom of the container. Water with little lime is generally suitable for irrigation; however, rainwater is particularly suitable. The addition of a fertilizer has also proven to be helpful so that the plant can develop optimally.
In principle, fertilization is only used during the growing season. So the first dose should be given in April; the final fertilization is carried out in September. During this time, the individual doses of the fertilizer should be made every four weeks. Products that contain little phosphorus are particularly suitable. A liquid fertilizer or a commercially available long-term fertilizer or a special fertilizer for green plants is optimal. The individual fertilizer portions are added to the irrigation water. Then the mixture is best poured into the top of the leaf crown; in this way the roots along the trunk can absorb the necessary nutrients.
Propagation and sowing
The reproduction of the Antarctic tree ferns takes place – as with all fern species – via spores. Until the plant is fully developed and fully developed, the plant goes through different phases:
- Formation of the pre-germ from the spores
- Fertilization on the pre-germ
- Formation of the main germ
- Beginning of plant growth
The spores can be taken from your own specimens yourself. For this purpose, a fern frond with the mature spores is separated from the plant. These can then be easily removed. To do this, hold the frond over a sheet of white paper and brush the spores down with your hand. These can then be used for cultivation.
The composition of the substrate plays an important role in the cultivation of the Antarctic tree ferns. Basically, permeable soils that are also poor in nutrients are suitable. Special potting soil or coconut fiber have proven particularly useful for this purpose. The potting soil is also mixed with a small amount of sand. Before the spores can be used, the substrate must be thoroughly moistened. The spores are then sprinkled on the surface of the substrate and gently pressed on. The seeds are only covered with a very thin layer of substrate. Now the cultivation vessel can be moved to a bright location.
During the germination period, which can be between four and nine weeks, the substrate must be kept moist regularly. However, under no circumstances should the earth get wet! The cultivation vessel is also covered with a foil or a glass. However, this cover must be permeable to light and the rays of the sun. Regular ventilation of the pot during the germination period is of particular importance; otherwise, mold may form in the soil.
During the first six weeks after budding, the vessel must never be in full sun. The seedlings are repotted around eight weeks after budding. Proceed with caution and make sure that the very young and freshly formed roots are not damaged. In its first year of life, the Antarctic tree fern should by no means be kept outdoors; Continuous cultivation in the greenhouse is optimal.
This is how the fern hibernates
Wintering plays an important role in the successful cultivation of the tree fern. If temperatures of -4 ° C are reached, the fronds die. However, the plant is not damaged by this process, as it sprouts again in spring. According to the literature, cultivation of the plant is possible down to a temperature of -12 ° C without additional protection in the open air, but in practice overwintering is often not successful in this case.
Styrofoam is ideal as protection against cold and frost, which is why it should be attached as a precaution. The construction consists of cut-to-size panels with a diameter of 12 cm. To attach the winter protection, the first step is to tie the crown together with a cord. In this way, the fronds stand straight up. Now the polystyrene sheets can be attached all around and the cord removed again. The fronds fall apart and look out of the box. A suitable styrofoam lid is only placed on the construction when heavy frosts appear. The fronds are completely cut off beforehand. The addition of bark mulch on the sides provides additional protection.
The following aspects must be taken into account when potted plants are overwintered:
- Location: frost-free, unheated room
- A greenhouse or cold house is ideal, or a basement room as an alternative
- keep only slightly moist during the winter
- Avoid drying out completely
Fight diseases and pests
The Antarctic tree fern develops diseases mainly through incorrect care. If the plant is moved to a very sunny location, the fronds tend to dry out. Individual sections then turn brown. In addition, incorrect pouring behavior can lead to the development of diseases. If the plant is continuously exposed to waterlogging, the symptoms of root rot quickly appear.
In addition to certain diseases, various pests also occur on the plant. This makes it possible for scale insects to be attacked. In this case, pustule-like shields with a lid or cup-shaped structure that are densely packed within crusty coverings present a characteristic damage pattern. In addition, sticky excretions of honeydew can be found. The infestation with scale insects can lead to crippling and stunted growth. The use of natural enemies is worthwhile as a preventive measure; these include, above all, ladybirds and parasitic wasps. If there is an acute infestation, the affected fronds can be freed from the shields with a toothbrush. Sprayings with various oily products that lead to asphyxiation of the pests are also used for control. Such products have a particularly gentle and targeted effect on the pests. Variants are used that contain, for example, paraffin oil.
If the plant is affected by the mealybug, the animals and their flaky excretions present themselves primarily in the area of the fronds. To protect against predators, the pest excretes a furry and woolly shell made of wax threads, by means of which it can be easily recognized. The consequential damage is yellowing and stunted growth. As a preventive measure, the targeted application of beneficial organisms such as ladybirds, parasitic wasps and bed bugs is again suitable. In the event of an acute infestation, the lice can be stripped off directly. Oil supplements are also suitable. If the plant is mainly cultivated in the greenhouse, the Australian ladybird can also be used for targeted control.
Conclusion
The Antarctic tree fern is the right plant for gardeners who want to have a lot of patience and time to watch their plant grow. Optimally cared for and, above all, equipped with suitable winter protection, the plant can be described as quite robust and resistant. Held in the greenhouse or outdoors, the farm brings an exotic note to any green area.
