Classification, origin and description
Common name: Ficus.
provenance: tropical or subtropical countries (India, China, Southeast Asia).
Genre description: it includes about 800-1000 species of plants, with variable bearing and size: in fact we find both plants of modest size, and plants that, in their native places, become large trees; or evergreen or deciduous plants. Generally these are delicate plants because they come from tropical or subtropical countries (India, China, Southeast Asia). A characteristic common to all Ficus, indeed to all the species belonging to their family, the Moraceae, is the presence in the tissues of lacticiferous channels, containing a white, dense, sticky latex (or latex), probably produced for antipredatory purposes. This liquid can be irritating to eyes and skin. In the Dorigine countries, this latex, made to come out from small incisions made on the trunk of some species of Ficus, produces a good quality rubber; therefore these plants are also important from an economic and commercial point of view. Ficus elastica is one of the most used trees for the production of rubber; it is of such importance that it is often indicated by the common name of fig of the gum. Another certainly older use that some species of Ficus have in common is that of a sacred tree and for this reason guardian of the temples.
It is interesting to dwell on the large dimensions and the considerable heights that some Ficus reach in their natural habitats, to understand well the grandeur and majesty of these species: the Ficus elastica and the Ficus benjamina can easily reach 30 meters in height in the Dorigo countries; if these species are planted and cultivated at other latitudes, in an environment with many of the characteristics of the original one, such as Sicily, they can reach 20 meters, a lower but always remarkable height. In the apartments obviously they do not reach those heights, but many specimens of Ficus easily reach 2-2.5 meters from the height, beyond which you can proceed to a containment topping to get more bushy plants. The parts removed from plants for multiplication can be used.
Ficus benjamina (website photo)
Species and varieties
The Ficus benjamina it is a plant native to Southeast Asia, present from India to the Philippines. It has a straight and slender trunk, flexible and elegant, with a very dense crown. The bark is smooth and light in color and tends to darken with age. The branches are thin and pendulous; From the branches of the old specimens, columnar aerial roots develop which serve to distribute the weight of the foliage which expands enormously horizontally once it reaches maturity. Ficus benjamina is an evergreen species, the leaves are elliptical with sharp apex, petiolate, not leathery; their length is about 7-12 cm, the margin is whole. The color is bright green when young while the coloring is darker is when the leaves are adult.
The Ficus elastica it also originates from tropical Asia. It has a relatively thin trunk, and tends to branch very much. In fact, in the places of origin it presents itself with a very horizontally expanded crown and supported by long columnar roots that branch off from the branches. The young leaves are wrapped in a red sheath, are ovate and pointed at the apex, even 30 cm long and are equipped with a robust petiole. The leaves of F. elastica also have a leathery consistency: this factor, in addition to the size of the leaf and the color of the sheath, allows you to clearly distinguish Ficus elastica from Ficus benjamina. The coloring of the leaves is dark green and shiny on the upper part, while on the lower part it is a more pale green. On the lower page the central rib stands out, which is red and very protruding. It should be remembered that the one just described is not the typical species but is the Decora variety, a plant obtained after many hybridizations. The typical species, for example, differs from the Decora variety by the shape of the leaves, which are markedly oblong and non-oval.
The Ficus lyrata it is native to western tropical Africa and has also, like F. elastica, very large, shiny and leathery leaves. However, the size of the leaves of F. lyrata can be much greater than that of F. elastica reaching even a length of 60 cm and a width of 25 cm. Furthermore, the leaves of F. lyrata differ from those of F. elastica also in their shape, which resembles that of the violin: in fact, the end of the leaf is much wider than its base. The edges of the leaf are markedly wavy; this is another distinguishing element with F. elastica. In the places of origin, the F. lyrata is an imposing tree, whose crown reaches 8 meters in diameter. It is an evergreen species.
The Magnolioid fig (Ficus macrophylla) is native to eastern Australia and is an imposing and majestic plant in its natural habitat, which reaches a height of 40 meters. It differs from the Ficus previously treated in many respects. First of all, the trunk in the old specimens is massive, voluminous and irregular, with a lead-gray bark. The aerial roots are imposing, in fact they descend from the large branches and when they are buried they form very spectacular colonnades. The foliage is impressive, because it is a plant that branches a lot, and for this it must be supported by the aerial roots. The most obvious distinguishing element is given by the leaves. The leaves of this tree are reminiscent of those of the Magnolia grandiflora (hence the name), therefore they are whole, have an ovate-elliptical shape and a length of about 25 cm. The similarity with Magnolia grandiflora is not limited to the shape of the leaves but also extends to the characteristics of the surfaces of the two leaf pages. In fact on the upper page they are green, shiny and free of fluff, while on the lower one, in addition to having a lighter green color, they have rust-red scales. Furthermore, they do not have a sharp stone as it is in F. elastica and F.benjamina. All the elements previously described differentiate it from the Ficus which is most similar to it or from the Ficus elastica. The magnolioid fig has in common with the Ficus elastica and with the Ficus lyrata the leathery and shiny leaves on the upper part and reads an evergreen species, a common characteristic of the latter also to the Ficus benjamina.
The genus Ficus includes a huge quantity of species, many of which have not had a large commercial diffusion such as F. elastica, F. benjamina etc. for a variety of reasons and are present mainly in some botanical gardens. The reasons for this absence or scarce diffusion can be traced back to the fact that some of them have little ornamental foliage and for this reason they are not among the marketable species, while others are more delicate and require attention that often the simple enthusiast is unable to supply and this limits their diffusion, or more trivially because some varieties, although beautiful and interesting, are not known by the general public, which does not require them. However, they deserve to be briefly described above all to offer a complete panorama of this genre and therefore to promote their knowledge.
The Ficus benghalensis finds its original range in Southeast Asia and tropical Africa. It can reach 30 meters in height and has leathery leaves with a largely oval or elliptical shape, whose length ranges from 13 to 25 cm. The leaves have a dark green color with bronze shades when young, while as an adult the pattern of light veins can be clearly seen on the leaf surface. On the lower page, a soft and short hair is detectable. It emits adventitious roots from the branches.
The Ficus buxifolia it is a plant originating in Zaire, with a rapid growth. The leaves, up to 6 cm long, are leathery and cuneiform, carried by thin and pendulous branches.
The Ficus cannonii it is a shrub that reaches 3 meters in height, but is very different from what we are used to seeing. The leaves are not leathery but membranous, up to 25 cm long. The shape is very varied, from roped to trilobed, always with a red central rib. The two leaf pages are chromatically different, in fact the upper one is brown-violet, the lower one is red-wine.
The Ficus diversifolia it is native to India and Malaysia where it does not reach large dimensions: we could call it a small tree. The branches are short, and bear broadly obovate or rounded leaves, with rounded or pointed apex. The leaves have a dark green color on the upper page, while the coloring can be from a more pale green to the fawn in the lower one. The fruits, yellow or red in color, are very ornamental.
The Ficus formosanum (Ficus from the island of Formosa) is a plant with round and persistent leaves, and needs more light than other varieties. It is very delicate.
The Ficus ispida (sin. F. oppositifolia), native to Asia and tropical Australia, is a bush or small pubescent tree, bristly in all its parts. The leaves, oblong and not leathery, have the whole or notched margin. Being thickly hairy on the lower page, they are particularly rough to the touch.
The Ficus neriifolia it is distinguished by the narrow and shiny leaves that recall those of the weeping willow. This species emits aerial roots easily, even in the first years of life.
The Ficus pumila, originally from China and Japan, is a climbing or creeping plant, the branches of which are dimorphic. In fact the young branches are thin and adhere to the support with adventitious roots. They have very small ovate and pointed leaves, dark green in color with very protruding ribs on the lower page. The adult branches, which however rarely form in our latitudes, are erect and woody and bear large ovate-oblong, whole, leathery and shiny leaves. The characteristic feature of this tree is that it behaves like a climber: in fact, the plant has a fickle stem that is incapable of supporting itself. In our latitudes it is cultivated by making it adhere to supports, or by letting the stems fall if we want to use Ficus for hanging baskets. In nature it is an epiphytic plant, that is, it is a plant that lives on another, using it only as a support.
The Ficus religiosa it is the sacred tree par excellence in India, planted near temples, in fact it is commonly called the fig tree of pagodas. It is a tree originally from Thailand and Vietnam and is a tall tree because it can reach 20 meters. Its branches are angular, erect and have numerous adventitious and taproot roots. The leaves, long petiolate, are heart-shaped, ovate-triangular, but are characterized by having a linear appendage to the apex, that is, they have a very acute end. The shape of these leaves bring to mind that of black poplar.
The Ficus retusa it has a very wide diffusion area that includes all of tropical Asia, from Malaysia to the Philippines up to Hawaii. It is a large tree with an erect bearing that closely resembles F. benjamina. The persistent and leathery leaves are 5-10 cm long and have a beautiful bright green color. The leaves of the Ficus retusa, briefly petiolate, can take a largely or strictly elliptical shape until they are obovate. It is a very vigorous plant.
The Ficus rubiginosa it is a tortuous shrub and very branched even when young, of Australian origin. It has fittonanti aerial roots that then snake on the ground and sprout forming dense thickets. The leaves are leathery, whole, oblong and cordate at the base, 8-10 cm long. The leaves have a dark green color while on the lower page they are pubescent when young and then hairless, except for the ribs. This dense and thin hairiness that is present at the juvenile stage of the plant, is tawny or reddish in color (from this characteristic derives the name of the species) and recalls the lower page of Magnolia grandiflora. There is also a variegated leaf variety.
The Ficus sicomorus it is a plant native to Syria, Egypt and Sudan. It is a very long-lived tree that reaches large dimensions. The leaves are symmetrical and variable in shape: from broadly ovate to elliptical to almost circular, with a rough surface. The length is approximately 8-10 cm, bluish-green in color when young, dark olive green as adults.
The Ficus triangolaris it is native to tropical Africa. It is a small evergreen tree with triangular leaves, dark green, thick and fleshy, 5 cm long with rounded edge. There is also a variety with variegated foliage, whose leaves have a wide cream-colored margin, variegated from dark green to light gray.
Ficus elastica var. decorate (website photo)
Environmental requirements, substrate, fertilizations and special precautions
Ficus are plants that thrive in a substrate with a pH between 5 and 6, therefore slightly acidic, but can also develop in a neutral soil or in a decidedly acidic soil. The soil must be particularly permeable and fertile. The fertility of the soil is naturally linked to the presence in the soil itself of many nutrients that the plant needs, although a certain rusticity of the various species of Ficus must be noted, which can continue to live even in rather poor substrates. The permeability of the soil is however an essential feature. This importance is given by the fact that, although it is true that Ficus like water and a moist substrate, it is equally true that these plants do not bear those poorly draining substrates, where the water stagnates, and not even the too frequent watering, where the soil, even if with good permeability, it does not have time to dry. Indeed, root rot is one of the most frequent causes of death for these plants. The most suitable soil is made up of one third of mature manure, one third of well decomposed leaf soil and one third of deric soil. A soil based on well-decomposed beech leaves and clay, all enriched with manure, can also be used. Instead, the usable acid soil is based on peat, which can be mixed with leaf soil or used exclusively.
We have just said that there must be no stagnant water in the soil. This means that it is important that the pot has excellent drainage, obtainable by placing a lot of coarse material on the bottom of the pot (for example, in a pot with a diameter of 12-15 cm, at least 2 cm on the bottom must be made of gravel or expanded clay or broken pottery shards etc.). It is advisable to check from time to time that the drain hole of the pot is not obstructed with residues of soil, because this would mean that the drainage has not been done properly. If water stagnation should occur, the plant warns us of its state of suffering with yellowing and subsequently the loss of the basal leaves, and with the impoverishment of the foliage as a whole. If, following this event, which occurs more easily in winter, it is ascertained that drainage has been done properly, the suffering of the plant is due to an excessive administration of water with irrigation.
Irrigation must be very abundant and frequent throughout the summer season, while in winter the amount of water must be very small. It is difficult, in winter, to give a time limit between one watering and the other because if the Ficus is kept in a heated environment (home, office), the time interval will be shorter, while if the plant is kept in a sheltered environment but not very heated, as can be the land of a building, we can say that the interval of time between one watering and another can also be monthly. However, before watering, one must always make sure of the conditions of the substrate, from which we will understand if irrigation is necessary or superfluous; this caution can avoid unpleasant inconveniences. Irrigation must be understood not only in the classic way, that is, as the amount of water poured into the pot, but also as water sprayed on the leaves. The function of this type of irrigation is precisely to provide water to the plant through the leaves. In fact the leaves are provided with stomata, which are microscopic openings that regulate the gaseous relationships with the outside. In relation to the external temperature conditions and the water requirement of the plant, the leaf can decide whether to open or close these openings. For example, stomata can be left open when the plant is in a water stress situation, to absorb atmospheric moisture.
Since during the summer one must try to maintain a humid atmosphere, it is particularly recommended to spray water on the leaves (preferably rainwater, because it is free of limestone) and to pass on the leaves themselves a sponge or a wet cloth. This summer leaf watering has as further aims to lower the leaf temperature and to clean the leaves themselves. Since the plant lives in a protected, closed environment (apartment, office, etc.), a considerable amount of dust settles on the leaves day after day, which cannot be removed by the action of the wind and rain precisely because the plant does not live outdoors. Dust limits the functions of the leaves. By sprinkling water on the leaves of the foliage and then passing a cloth, or leaving the plant outdoors during a rainy day, the dust will be removed and the leaf will start to vegetate again without any obstacle.
We have mentioned many times the importance of atmospheric humidity. Paying attention to this aspect can be decisive especially in the home environment. The optimal humidity rate is around 70-80%, and to obtain this humidity it would be sufficient to place a good amount of water in the saucer, which, with the temperatures present in the apartment or office, will evaporate creating that atmospheric humidity to which the Ficus do not they can give up. It should be remembered that there must be no contact between the water present in the saucer and the vase; therefore a support preferably made of plastic material, high enough, on which the vase will be placed, must be placed between the pot and the saucer. This plastic support is also useful for separating the pot from the water we administer with irrigation; without this expedient the roots would always be wrapped in a wet earthen bread and this situation would be the bearer of root rot.
It is necessary to take great care of the light exposure for the Ficus. In fact, they do not need and do not like direct sunlight, but they also prefer bright environments. Exceptions are some varieties such as Ficus diversifolia and Ficus pumila, because they can live in very shady environments. If during the spring-summer season we decide to place our Ficus outdoors, we must remember this aspect, that is a lot of light but not direct; we will then place the Ficus under a transparent plastic canopy, which will ensure the necessary brightness by avoiding sunlight to hit the leaves. Furthermore, the Ficus can be placed under a pergola, or under a porch or inside a veranda; as you can always see in a sheltered environment. In fact, when the sun's rays hit the leaves, they present burns and discolorations, especially if they have spent the cold season in a place sheltered from the sun's rays. In winter the plants will have to be housed in the house because, being native to tropical environments, they fear the very low temperatures that can occur especially in the north. Even in winter the light is particularly important, in fact they will be placed near a window, through which they will receive the light necessary for photosynthesis. In the southern regions, where the climate remains mild throughout the winter, Ficus can remain outdoors without light and temperature problems.
These plants find good living conditions in apartments and offices, especially in relation to temperature. In fact, in these environments the temperature, even in the middle of winter, is always stable around 18-20 ° C. This temperature is sufficient for the Ficus to live and thrive in the apartment, even if the ideal temperature that the Ficus would need would be slightly higher, that is around 20-22 ° C in the hours of light, and around 15-18 ° C at night. Other Ficus, like F. benjamina, also bear lower minimum temperatures, around 13-15 ° C. F. pumila, which is a climbing species, can also live with a temperature of only 10 ° C and in mild climate areas it lives outdoors all year round.
Obviously it is impossible to reproduce the conditions of the original habitat in our apartment, however by adopting some minimum precautions we will avoid unnecessary suffering for the plants, such as those due to the air currents that can be created inside the houses, or the thermal shocks which are also particularly harmful.
Multiplication and pruning
Multiplication by cuttings is certainly the most used and easiest method to produce new plants. We said that pruning can give the opportunity to multiply the Ficus present in our apartment; however, it should be noted that the branches that root more easily and more quickly are those removed from the top of the plants. Portions of 5-10 cm long branches are taken, if we want to multiply Ficus such as benjamina, pumila etc., while if we want to multiply Ficus such as F. elastica and F. lyrata the cuttings can be even longer, between 10 -15cm. The cut must be made just below the point where the leaves are inserted, which takes the name of node; in fact it is precisely from the knot that the roots will develop. The leaves of the node where we made the cut will be removed because this part will be buried. The leaves that remain on the surface will be cut in half to avoid perspiration as much as possible, ie the loss of liquids. The cuttings thus obtained will be planted in a substrate composed of a mixture of sand and peat in equal parts. The most suitable period to carry out this operation is from April to August, but with different methods in the passing of the months, because the temperature conditions that occur in such a long period of time are very different. In general, it is necessary to ensure that the cuttings have a fairly high temperature, ranging from around 18 ° C for F. benjamina, up to 21 ° C - 24 ° C for F.elastica and Ficus lyrata. As if this were not enough, a high environmental humidity is required. In the months of April - May, to reach these conditions it is necessary to place the cuttings in a large and deep container, covered with transparent plastic film or with glass plates, in order to create the right humidity and the necessary temperature inside the container. The use of this mini-greenhouse is due to the fact that in April-May the external temperature is not yet such as to favor aging and the temperature drops are not uncommon, which can stop the rooting and damage the cuttings. The cuttings could also be housed in the house, but in homes the heaters are already off in those months and even here, to ensure the necessary temperature and humidity, one should resort to the mini-greenhouse. As we will see later, the use of plastic film, to ensure the necessary humidity, is not handcrafted, but is also used in large flower companies.
Later in the season, when the temperature begins to stabilize at 25-30 ° C and more, in June, July and August, the multiplication procedure must slightly vary. If we apply the method described above we risk seeing the cuttings rot and die. In fact, the temperature and humidity conditions that would occur inside our container covered by glass plates or plastic film would be excessive and, therefore, would not bring the cuttings to take root but to their death. To avoid this epilogue we will place the cuttings in a vase, placed in a large warm environment, as can be a greenhouse, always avoiding direct exposure to the sun's rays. This environment must be warm but also sufficiently ventilated; to create the right humidity, the waterings, in this season and in this room, must be frequent. With these measures, the ideal humidity and temperature conditions are created to stimulate rooting.
Another particularly simple method of obtaining new seedlings is to root the cuttings in water; repotting will take place later, when the root system is sufficiently developed. Even with this multiplication system the necessary ambient temperature must be guaranteed.
The large flower companies also practice multiplication in winter and, since the technique is similar to the one just illustrated, I will only mention it briefly. The cuttings are harvested between November and January, they are left to drain the latex for a day, after which they are placed in a container heated to a temperature between 25-30 ° C. The substrate is the one indicated above. Once the planting is complete, water abundantly and cover everything with plastic film, in order to create the necessary humidity for rooting. If the conditions are optimal, the rooting takes place after less than a month, in 20-25 days, and the seedlings can be immediately repotted, although it is preferable to wait for the following spring, maintaining the suitable temperature and humidity throughout the winter.
The multiplication of this genus of plants is not particularly difficult, little attention is enough; however, if we absolutely do not want to fail, we can use products that facilitate rooting, that is, rooting or rhizogenic hormones, which stimulate the release of roots and therefore take root.
The other multiplication system is that by layering. The layering is a multiplication technique consisting of a series of operations, carried out in May-June on the highest branches. The first of these operations is an incision, made with a knife, practiced in the bark of the branch which we would like to make a seedling. The incision can also be caused by tightening an iron wire around the branch, the thickness of which must be proportional to the branch. Once this operation has been carried out, it is only necessary to coat the part of the incised branch with sphagnum or peat and then wrap it all with plastic film, tied a few tens of centimeters above and below the incision. It is important to make small holes on the plastic film to allow the passage of air, and a larger hole to moisten the substrate whenever it appears dry.
There are two other secondary methods of multiplication: leaf cutting and root cutting. Leaf cutting is particularly used for F. elastica, while root cutting is applicable to all Ficus species. They are both underused multiplication systems.
If we have grown the Ficus plant respecting all the requirements required by the plant itself, such as temperature, substrate, brightness, humidity, etc., to live and develop, we will have in a few years a very lush plant that will occupy a growing space. Then pruning will be necessary, the residues of which can be used for multiplication. It is preferable to prune the plant in spring, at the vegetative restart, even if it is possible to do it throughout the year. Obviously the pruning has the purpose of containing, within certain limits, the development of the crown; when it is substantiated in the elimination of young shoots it is called topping. The topping obliges the plant to thicken the foliage, and therefore allows us to obtain more bushy and compact plants, especially if it is practiced on young plants. On the other hand, the trimming of the herbaceous shoots on highly developed and adult plants will not make us obtain particularly thick plants; it will be the removal of the lignified branches to stimulate the branching and therefore to thicken the vegetation. The pruning of the larger branches will be carried out in winter, also because in that period the latex is less abundant, and what will come out will have to be blocked with cicatrizing paste.
Parallel to the growth of the foliage there is the growth of the roots, and the plant may need to be repotted in a larger pot, because the previous one has become insufficient; or it may happen that, although the plant is already in a large pot, a reduction of the root system may be necessary. In the first case, it is sufficient to obtain a more capacious pot, to find the suitable soil for the Ficus, and to proceed with the repotting, paying attention above all to the drainage. This repotting can be done in any season. In the second case, however, we must remove the roots; it is preferable to carry out this operation in late winter or spring. In fact, in March-April the temperature is not yet high and, since we will have to remove a certain amount of roots, it is preferable to proceed in that period because the water requirement of the Ficus plant is rather limited. In this way the Ficus will not suffer excessively from the reduction of the root system, as would happen if this operation were carried out in the middle of summer, manifesting itself with evident wilting. Before cutting the roots, it is necessary to free them from the soil; sharp scissors must always be used to give a clean cut. La quantità di apparato radicale asportabile potrà essere anche della metà. Infatti le radici dei Ficus ricrescono in breve tempo e con facilità, per cui la pianta supererà questo momento abbastanza agevolmente. Non è possibile stabilire un intervallo di tempo fisso tra un taglio delle radici e il successivo, perché esso dipende anche dalle condizioni generali di salute della pianta. Se la pianta gode di ottima salute, alcuni segnali che ci avvertono della necessità del taglio delle radici possono essere la fuoriuscita delle radici dal foro di scolo, oppure il pane di terra sollevato rispetto al bordo del vaso, perché spinto in alto dalle radici. E possibile, però, ricordare una regola generale: quando il Ficus è giovane, il rinvaso può essere fatto anche ogni due-tre anni perché il suo sviluppo è rapido, quando la pianta ha molti anni, laccrescimento è più lento e possiamo ridurgli lapparato radicale anche dopo più di sette anni. Dopo aver collocato la pianta nel vaso ed aver versato il nuovo terriccio, è necessario pressare in modo deciso il terriccio intorno alle radici rimaste e annaffiare subito dopo. Nel periodo successivo presteremo qualche attenzione in più alla pianta rinvasata a cui abbiamo tagliato le radici per poter monitorare giorno dopo giorno la ripresa vegetativa e per non far mai mancare, come sempre, tutte le condizioni ottimali di vita.
Malattie e parassiti
I Ficus, come come tutte le piante, possono essere colpiti da malattie causate da funghi, oppure possono essere attaccate da insetti parassiti. Va sottolineato che i Ficus sono molto resistenti alle malattie, mentre sono sensibili agli attacchi dovuti a insetti parassiti, che provocano maggiori danni. Per evitare di avere piante pesantemente infestate, è opportuno monitorarle continuamente e con attenzione, anche perché alcuni insetti attaccano la pagina inferiore o si nascondono nelle gemme.
Tra gli insetti che aggrediscono i Ficus troviamo i tripidi, gli acari e le cocciniglie.
I tripidi sono piccoli insetti, appartenenti allordine dei Tisanotteri, i quali posseggono un apparato boccale pungente-succhiante. I tripidi provocano danni allapparato fogliare, sotto forma di deformazioni e bollosità; quando lattacco è avanzato, questi sintomi possono evolvere in delle tacche di colore marrone.
Altri tripidi, oltre alle deformazioni fogliari, provocano delle decolorazioni fogliari con strisce di colore verde chiaro a puntini. Alcuni tripidi possono attaccare la pagina superiore della foglia mentre altri quella inferiore ma in entrambi i casi leffetto causato dalla loro presenza è un rallentamento della crescita. Si combattono con prodotti a base di piretro.
Se sulla pagina inferiore della foglia troviamo delle ragnatele e le foglie cominciano ad assumere una colorazione giallastra, siamo di fronte ad un attacco di acari. Gli acari sono insetti affini ai ragni (classe Aracnidi), dotati di un apparato boccale pungente-succhiante come i tripidi. Provocano danni simili a quelli provocati dai tripidi ovvero decolorazioni sulle foglie, a volte puntiformi, e rallentamento della crescita. In più, le punture di questo insetto causano raggrinzimenti e incurvature del lembo della foglia. La condizione necessaria per il loro sviluppo è la secchezza dellambiente, infatti il loro periodo di massimo sviluppo è lestate. Se lattacco si verifica dentro una serra, la soluzione più semplice per combatterli è aumentare lumidità allinterno della serra stessa. La lotta agli acari è difficile perché essi si rifugiano nelle fessure della corteccia e delle gemme, e perché riescono a generare ceppi resistenti agli antiparassitari. Si possono combattere con alcuni dei prodotti usati contro i tripidi.
Le cocciniglie sono insetti emitteri che si nutrono della linfa delle piante. La cocciniglia che trattiamo è chiamata comunemente cocciniglia cotonosa ma il suo nome scientifico è Planococcus citri. Questa cocciniglia, oltre a rallentare lo sviluppo della pianta, per riduzione dellattivita fotosintetica, lascia sulle foglie una secrezione biancastra e cotonosa. I rametti attaccati deperiscono, le foglie ingialliscono e successivamente seccano. La presenza di cocciniglie è sempre la condizione ideale per lo sviluppo di una malattia chiamata fumaggine; la fumaggine è un fungo che prospera sulla superficie delle foglie in presenza delle secrezioni zuccherine delle cocciniglie. Per combattere questo insetto ci si può avvalere di prodotti chimici specifici, però si può anche adottare qualche sistema semplice, economico ed innocuo. Infatti, se le piante sono coltivate in un appartamento, in ufficio o comunque in un ambiente chiuso e abitato, è sempre sconsigliato ricorrere alla soluzione chimica, perché rischiamo di inalare noi stessi i prodotti usati contro i parassiti, e perciò ritengo sia giusto, ove possibile, promuovere soluzioni alternative. Infatti, basta una minima quantità di qualsiasi detersivo da stoviglie, diluito in acqua, per ottenere una soluzione saponosa, che, una volta spruzzata o distribuita con un pennello sulla pianta, contrasterà efficacemente il parassita. In alternativa, si ottengono gli stessi risultati utilizzando alcool denaturato, passato sulle superfici della pianta infestata con un batuffolo di cotone.
Eovvio che queste sono soluzioni ideali per ambienti domestici dove le piante non sono in gran numero ed hanno dimensioni limitate.
da I FICUS: GLI ALBERI DA SOGGIORNO di Paolo Pecchioli
Altre immagini (clicca sulla specie)
Ficus hispida con frutti (siconi)
Ficus rubiginosa variegata
Ficus elastica var. originaria
Ficus elastica var. decora variegata