HOW TO GROW AND CARE FOR OUR PLANTS
The genre Polystichum belongs to that group of plants which are commonly called FERNS includes very popular and widespread species in our apartments.
Clado: Ferns and related groups
Species: see the paragraph on "Main species"
The genre Polystichum belongs to that group of plants which are commonly called FERNS.
They are plants that belong to the great family of Polypodiaceaewhere we find from 193 to 223 genera and 7500 species. In Italy we have just over 70 species enclosed in about twenty genera.
For many years these plants have been shrouded in mystery because it was not possible to understand how they could multiply. Only in 1850 a German bookseller was able to unravel the mystery: he had observed on the underside of the leaves, the spores, through which the plant multiplied.
There are about 200 species of Polystichum, we recall the most common:
The fern Polystichum acrostichoides is a delightful fern native to North America. It is characterized by pinnate fronds of a beautiful very intense green color which when young, are covered with whitish and shiny scales.
It is a species that lives mainly in the open and reaches a meter in height and 60 cm in diameter.
The fern Polystichum aculeatum it is native to Europe and North America with fronds of a beautiful glossy green color and leathery consistency. Both the stems and the ribs are covered with brownish scales. It is a plant that grows mainly outdoors and develops up to a meter in height forming delightful bushes.
The fern Polystichum falcatum is a beautiful plant native to Japan and China with dark green and shiny pinnate fronds.
It is a plant that grows up to one meter in height and is very suitable for growing in the apartment. Very characteristic and beautiful to see are the sori that form on the lower page of the fronds (photo top left).
The fern Polystichum setiferum is an evergreen terrestrial plant that forms extraordinary dense bushes. In fact, it grows up to one meter in height and 1.5 m in width. It is very suitable for growing in gardens but is found spontaneously in different environments such as mountain cliffs or tropical forests.
The juvenile fronds are covered with numerous white-brown scales.
The species is divided into three groups:
The fern Polystichum lonchitis hto some very showy, leathery fronds of a beautiful intense green color. Very characteristic and beautiful to see are the sori that form on the lower page of the leaves (photo below right).
There are several cultivars among which the most widespread is the Polystichum lonchitis'Cristatum'.
The fern Polystichum munitum it is native to North America.
It is a beautiful fern suitable for growing in the garden where it forms beautiful bushes that are wide and up to one meter high.
The fern Polystichum lobatum native to European forests, very suitable for outdoor cultivation with shiny and leathery fronds.
In general, they are easily distinguishable from higher plants in that they are equipped with classic visible reproductive organs such as flowers and from lower plants (mosses, lichens, fungi, etc.) as the plant is a hornthat is to say a plant well formed in all its parts therefore provided with root, stem, leaves, pots, pith, etc. with the exception of the reproductive organs, that is the flowers.
Leaves with sporangia on the underside
The FERNS to reproduce they produce spores (hence the name ofSPOROPHITE) clearly visible on the underside of the leaves. The spores are contained within SPORANGIUM which are none other than the capsules in which they mature SPORES. In turn, the spurs are grouped into so-called formations SORI.
The spore is carried by the wind and falls into the ground and germinates. From its germination an independent plant is born that produces GAMETI said PROTALLO or GAMETOFITO. On this prothalus sexual organs are formed, ANTERIDS (male) e ARCHEGONI (female) where the ANTEROZOI and the OOSPHERE mature respectively. The male anterozoan moves in the plant thanks to the water (rain, dew, etc.) and goes to fertilize the newly fertilized oospherache (FERTILIZED EMBRYO) germinates immediately remaining in the Archegonium (in this phase the embryo produces a root asorta called austorium which sinks into the tissues of the gametophyte to be able to nourish). From this embryo the fern plant we know will be born.
Plants of the genus Polystichum they must be placed in an area of the house where there is not much light even if, among the different types of fern it is the most robust genus and tolerates exposure to light better than other plants (obviously never direct).
The dark green color of the leaves helps them to get the most out of any type of light and as they do not bloom, ferns do not need as much light as flowering plants absorb. Furthermore, in nature they are undergrowth plants for which the shade is their ideal environment.
Ferns do not need special attention: once you understand their needs, cultivation is very simple. First of all, remember that the optimal average temperatures are around 18 ° C and must stay away from drafts. If you see that the fern grows well in the place where you have placed it, do not move it. It means that in that place it has found a microclimate. ideal.
A recommendation that applies to ferns but which I recommend for all plants: NEVER use polishes for the leaves. In fact, these products block the plant's glistomas, preventing it from carrying out its normal physiological functions. To clean the leaves, simply use a damp cloth.
The main problem for ferns is humidity. ' In fact, an environment that is too dry or too hot causes serious damage.
Generally the Polystichum, despite being robust plants they are sensitive to dehydration, when they stay for too long in a dry environment. For obvious this inconvenience it is essential to keep the environment around the fern moist with constant nebulizations, at least twice a day during the hot season. slows down the loss of water by the fronds.
Another system is to put the pot on a saucer full of pebbles and then fill it with water, making sure that the bottom of the pot is not immersed in water as in this way the soil of the pot would become saturated with water, causing the roots to rot. This system allows, in hot weather, to evaporate the water in the saucer which consequently moistens the surrounding air. It is advisable to remember to fill the saucer whenever the water has evaporated.
In any case, the soil must always be moderately moist.
TYPE OF SOIL - REPOT
Generally the Polystichum they have a rapid growth therefore when the plant has reached an excessive size, it is repotted in March. The normally dry basic leaves are removed and placed in a slightly larger pot.
Put on the bottom of the vase a consistent layer of gravel and small stones that serve to facilitate the flow of water. The compost should consist of three parts of peat, 2 parts of coarse sand and a good dose of basic fertilizer.
Throughout the spring-summer season it is necessary to carry out regular fertilizations, twice a month, with liquid fertilizers to be diluted in the irrigation water. In other periods they must be suspended.
Use a fertilizer that in addition to having the so-called macroelements such as nitrogen (N), phosphorus (P), potassium (K) also contains the so-called microelements, that is to say those compounds that the plant needs in minimal quantity (but it still needs them ) such as magnesium (Mg), iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), boron (B), molybdenum (Mo), all important for a correct and balanced plant growth.
The Polystichum as ferns, they do not bloom.
For the Polystichum we cannot speak of pruning. The leaves that gradually dry up must simply be eliminated to prevent them from becoming a vehicle for parasitic diseases.
Make sure that the tool you use for cutting is clean and disinfected (preferably over a flame) to avoid infecting the tissues.
Multiplication can occur in two ways: for portions of rhizomeor for propagation by spores, the latter not easy to realize.
MULTIPLICATION BY PORTIONS OF RHIZOME
In February, before the vegetative restart, 8-10cm long cuttings are taken from the ends of the rhizomes bearing at least one leaf and small pots containing peat and sand are placed. They are kept in a warm and humid environment until the cuttings have rooted.
MULTIPLICATION BY SPORE
Spore multiplication is a difficult technique to implement in domestic conditions. In any case, if you want to try, a procedure that can be attempted in the home is explained below.
In spring, a fern leaf containing the spores is cut, scraped and dropped into a sheet.
A box is then prepared which contains moorland and peat in equal parts and the spores are arranged. Then water in moderation so as not to form pits or holes in the soil and put a glass plate or a transparent plastic sheet on top. At this point, put the box in the dark and at a temperature of about 20-23 ° C, taking care to keep the soil always moist. The glass plate or plastic sheet is opened every day to eliminate any condensation that forms.
After about 2-3 months the first seedlings will be born and at this point it is necessary to move the box to a brighter position (but not too much) and remove the glass plate. have a diameter not exceeding 6-7 cm.
PARASITES AND DISEASES
Falling dry leaves
This symptom means that the plant does not have the right water balance. It is necessary to increase watering and humidity.
Remedies: as a first step it is advisable to immerse the pot in a bucket of water so that the earth gets soaked, then it is drained well and then put it back in its place by regulating the watering and humidity in a more correct way.
Leaves pale and discolored
If the leaves show this symptom, it means that the plant is too exposed to the sun.
Remedies: move it to a more suitable place.
Curled leaves occur when the temperature is too low.
Put off: Move the plant to a warmer place.
Dark edged leaves that wither quickly enough
If this symptomatology occurs, it means that the environment where your fern is located is too hot.
Put off: Move the plant to a cooler location.
Leaves with dark spots
If this symptom is present, it is likely that the plant is undergoing a fungal attack, most of the time due to water imbalances, i.e. excessive stagnation of the water in the saucer.
Remedies: remove the affected parts and use specific fungicides products.
The leaves begin to turn yellow and fall off
It can be subject to infestations by the cochineal, both the brown cochineal and the mealy cochineal. Recognizing them is very simple: just look at them with a magnifying glass and compare them with the photos shown. They are unmistakable, you can't go wrong. If you try to scratch them with your fingernail, they come off easily.
Remedies: they can be eliminated using a cotton swab soaked in alcohol or you can wash the plant with water and neutral soap by rubbing gently with a sponge to remove the parasites. Once this was done, the plant was rinsed to remove the soap. Only in case of severe infestations is it recommended to use systemic pesticides.
The name of the genus Polystichum comes from two Greek words: poly"A lot" and stichos «Series» this to allude to the sori arranged in rows ordered on the lower page of the leaves.
This fern is widely cultivated for the production of fronds used for the packaging of flower bouquets like Asparagine.