Begonia belongs to the begoniaceae family and is widespread in all regions, from tropical to warm temperate ones. There are about 900 species, most of which are perennial, which can be divided into 3 main groups: tuberous begonias, rhizomatous begonias and collated root begonias.
The begonias they are most famous for their cultivation as annual plants. The varieties used for cultivation as flower annuals are the begoniette also called foreverfiorite and from the Latin name Begonia semperflorens. These are annual seedlings to be placed in full sun and with limited growth: they reach a maximum height of 30-35 cm.
The begoniette, given their low cost and their splendid blooms, are much used in the ornamental field. There are many varieties of begoniette that differ mainly in the color of the flower and the color of the leaves. They are mainly begoniette with light green, dark green or red-leafed leaves. As for the flowers, on the other hand, these are usually white, pink or red and this allows you to create nice color games with different cultivars.
Origins and classification
The begonias they are part of the family Begoniaceae formed by more than a thousand species. These are herbaceous plants, most of them usually with persistent leaves. We can find very different sizes and bearings. It is difficult to give a general description and it is better to deal with each variety individually in order to be able to best describe its characteristics and specific needs. The only aspect common to all the species is that of having on the same plant male flowers and female flowers. From these develops a capsule containing a large quantity of very small seeds. We can generally divide them into three categories: those with roots tuberous, those with rhizomatous roots and those with collated roots.
The tuberous begonias prefer positions in the sun or partially shaded, in any case however, sheltered from currents of cold air. The ideal temperature for this plant is 18/20 degrees; during the winter the temperature must not fall below 5/7 degrees. The best time to plant them is March-April. Initially it is advisable to place them in small pots, about 7/8 cm deep, and then, when the first shoots appear, to medium pots of about 10-15 cm and, finally, to 15/20 cm containers. To obtain large flowers it is necessary to reduce the plant to a single stem, with some lateral jet.
General cultivation advice
Climatic requirements: they absolutely don't like the cold. There are more or less rustic ones, but almost all do not tolerate temperatures below 10 ° C. However, they are generally delicate plants that can react badly even at a slightly colder current. This is why many of them are considered indoor and greenhouse plants.
Exposure the ideal location is the sun or the partial shade. They are undergrowth plants and place them under a tree or in any case in an area where the light is shielded from the leaves can be a winning choice.
Irrigation they love a high environmental humidity, so during the summer you have to irrigate them regularly, without leaving stagnations (due to rot). It is also important to create a habitat similar to that of the rainforests, therefore vaporisations on the leaves are welcome, especially on the hottest days. However, care must be taken that the area is well ventilated because if the humidity is too stagnant it can cause cryptogamic problems.
Fertilization: from the vegetative restart the bi-monthly administration of a liquid fertilizer with a high potassium content is advisable.
The faded branches of the rhizomatous species and the fasciculata roots must be cut in March, before proceeding with the repotting. If the species is particularly luxuriant, it is important and recommended to trim often, to prevent the branches from becoming too long and thin.
they must be fairly frequent but not excessive; in fact, between one watering and another, the root surface must have time to dry. More frequent in the summer, to be reduced to a minimum during the winter. In summer it is important to vaporize the leaves.
Use one of liquid type, which should be administered from May to September every 15 days.
Rhizomatous and fasciculated begonias can be grown both in greenhouses and in apartments. These plants love illuminated positions but not direct sunlight; in summer they like the shade especially if the temperature is above 20 degrees. In winter the temperature should be around 10-15 degrees. They are generally planted in 15-20 cm pots.
Pests and diseases
The tubers and roots are often affected by the punches, which feed on their own roots and pierce the tubers, and from the eel-eelula, which deprives the plant of nourishment. Mite attacks are also frequent, affecting all species and preferring younger and tender plants, damaging the buds, weakening and deforming the leaves.
Among the most common diseases we find gray mold, which manifests itself with dark spots on the leaves and on the flowers and white and powdery spots on the stems, the black rot of the roots, which causes them to rot, and finally the bacteriosis of the begonias, which causes the formation on the leaves of spots that gradually extend to the whole leaf, making it rot.
- Various types of mold and cryptogams: lead to the appearance of spots of various colors. Usually it is Botrytis cinerea or oidium. In any case it is good to regulate the environmental and soil humidity and to aerate the area as much as possible. If the problem is serious it is good to resort to specific curative products. Facilitated in its diffusion by very dense plantations. The affected parts and any moldy soil must be eliminated, as well as treating the plant with an anticryptogamic product.
- Root rot: manifests itself with leaf yellowing and subsequent loss of vitality of the plant. We can try to save it by extracting it from the ground and after careful cleaning of the tubers or rhizomes (and maybe a wash with specific products) insert it in a new container with a new substrate. You can continue the treatment with irrigations added with the specific product.
The flower of perfume
The Begonia is considered one of the fifty plants identified by NASA scientists for possible use within spaceships or aerospace projects.
Although in the vegetal landscape it is not known for its particular curative properties, the Begonia plant is optimal for perfuming the rooms and giving each space a pleasant and relaxing atmosphere.
The peculiar characteristic of this species is the conformation of the roots which are dark and irregular tubers. They are usually rather compact plants but rich in foliage. The leaves are large, palmate and serrated. They carry flowers with very bright colors and there are cultivars with simple, semi-double or double flowers and various sizes.
All the varieties need a complete winter rest during which the tuber must be kept in its pot in the dry and protected from the cold until the vegetative restart. The tubers must be planted outdoors or in pots at the end of May and beginning of June after having them "strengthened" in a cold bed. For the cultivation in pot it is advisable to follow the period of "vegetation", described for the B. evansiana, in March-April. The vases can be kept outdoors or indoors. Once a month has elapsed from the final planting in pot, it will be useful to administer liquid fertilizer every fifteen days for the entire duration of the vegetative cycle.
They are varieties as we have said of tropical origin so almost all over the Italian territory need to be withdrawn. The tuber can be kept in the dry pot throughout the winter at temperatures no lower than 5 ° C. If instead they were in the open ground they should be extracted and left to dry in the air, so that they do not create mold, and then withdrawn to a cool, dry place.
The fastest methods to multiply b. tuberoses are the division of the tubers and the cutting.
The first is done by dividing a large tuber into small sections, paying attention to the presence of at least one eye in each one.
The cutting, always spring, is obtained by taking basal stems with a portion of tuber and putting them to root in a very light compound with temperatures of about 20 ° C and high environmental humidity.
The species is native to the Asian continent. They are compact plants and therefore ideal for cultivation in the open ground, but also in pots.
It has large leaves colored in medium green on the upper part and carmine on the lower one. It blooms in summer producing racemes of pretty large pink flowers. They want a light soil based on peat or woodland and still acid. Before planting (usually done in April or at most March in the hottest areas of our country), you have to wait for it to become acclimatized. It is sufficient to place them in a box with light substrate and expose it to the sun so that the tubers feel the warmth of the sun. As soon as you see the first leaves you can put them permanently.
They can always be kept in the ground only in those areas of Italy where temperatures never drop below 5 ° C. Elsewhere it is better to extract the tubers and let them dry in the air and then withdraw them in a cold greenhouse where you will never have to freeze.
Note: in recent years, nursery owners have managed to create some varieties much more resistant to cold. They are also recommended for continental climates, therefore they can reach around -10 ° C. It is about begonia grandis subs. Evansiana and the begonia grandis subs. Evansiana var. Alba (the first carries pink flowers, the second white). They reach 60 cm in height and are an excellent opportunity for shaded areas, both for beautiful decorative leaves and for flowers. An abundant straw and leaf winter mulch is recommended.
They have long rhizomatous stems that widen horizontally and sometimes have a falling pattern. They are more appreciated for the leaves (decorative due to their shape and bright colors) than for the flowers, which are very difficult to obtain in domestic cultivation.
They tend to be indoor or greenhouse plants. They want a bright environment, but not direct light and temperatures of at least 15 ° C (but the ideal is from 18 to 23). They need regular irrigation and fertilization with products for green plants during the vegetative period. In winter the treatments can be almost totally suspended. They should always be kept in rather small pots due to the size of the plant.
They multiply easily by division of the rhizome or by leaf cutting.
The technique is very particular and specific almost only of the begonias: it is necessary to make incisions along the veins of the leaves. They must then be placed on a light mixture which must be kept constantly humid and at a temperature of about 25 ° C. From the engravings will start new plants that can be transferred to individual jars.
Some rhizomatous begonias: Masonian, Cleopatra, boweri, manicata, x erythrophylla
We will look into the Begonia rex in particular since it is the best known and most widespread.
It is native to the Himalayas and over time many cultivars (in particular belonging to the Cultorum group) have been developed that are appreciable for the great variety of leaf shapes and colors.
It wants a bright exposure, but sheltered from the direct rays of the sun. The crucial aspect is to keep irrigation under control. The soil should never be too wet due to the risk of causing rottenness. During the vegetative period in general the ideal is to water a fly a week leaving the substratum to dry well between once and the other. Liquid fertilizer can be administered weekly. As the growth slows down, the water intake is also reduced. The pots must have good drainage and the ideal composition for the substrate is formed by a 1/3 of garden soil, 1/3 of compost and 1/3 of peat.
It is also important to maintain a high environmental humidity, especially during the winter if the area is heated. The ideal is to place the plant on a saucer filled with water and pearls of expanded clay (without however the roots being in contact with the liquid). The ideal temperature ranges from 13 to 20 °.
BEGONIE WITH ROUNDED ROOTS
They are generally begonias of small dimensions but with very developed roots.
There are many varieties and they can have a prostrate, hanging, but also shrubby habit. The best known are: B.albo-picta, B.coccinea, B.corallina, B.fuchsioides, B.haageana, B.metallica.
However, the one most commonly found is begonia semperflorens, the begonietta commonly used in flower beds or pots. In reality it is a hybrid between the begonia cucullata and the schmidtiana. It is treated as an annual visa that in most of our country fails to survive the winter. In the far south we can also keep them for a second year. They prefer a slightly acid and well-drained soil. The ideal exposure is the partial shade. They also support full sun, but it can happen that the leaves dry up on the edges. The ideal temperature ranges from 13 to 20 ° C.
The irrigations must be very controlled because the most frequent problem is root rot, the cause of most failures. The fertilizations must be weekly.
Begonia rex is a begonia belonging to the group of rhizomatous begonias and is most probably the most known and purchased variety of this species. Its origins are Indian and it is a plant that at our latitudes is mainly cultivated in the apartment. Much appreciated for its variegated leaves with white and red shades, begonia rex blooms in summer, in the months between June and September, and produces small white flowers that are inconspicuous compared to the beautiful leaves. The leaves are also very appreciated for their rough and wrinkled appearance.
Begonia rex does not reach large dimensions and has a height almost always between 20 and 40 centimeters.
If you decide to grow this plant in your apartment you will need to ensure it is bright but without direct light. Begonia rex is a plant that lives well however also in semi-shadow environments. Despite being a plant that suffers intense cold in the winter months, begonia rex during the summer can be without problems outdoors, as long as it is not exposed to direct sunlight.
As for the watering of this plant, it is a plant that has normal needs but suffers from water stagnation.
Do not overdo it with water and take care that the soil always dries between one watering and another. In winter the quantities of water must obviously be reduced but without a standard: in this period the best method is to touch the ground to understand when this is dry before proceeding with a new watering.
The cultivation soil of the Begonia rex must be of good texture and drained, a soil with intermediate characteristics in short, even if this plant is not demanding in terms of soil.
One of the most widespread varieties of begonia, most cultivated and most appreciated in the ornamental field is without doubt the Begonia elatior. It is a plant that is easy to find in nurseries almost all year round, with flowers available in many different colors ranging from pink, red, orange, white to yellow.
There begonia elatior It is a begoniacea cultivated mainly as a houseplant which however can be exposed outdoors during milder weather months. Of small dimensions that never exceed 20 cm in diameter and form small compact bushes, the begonias elatior are plants that look good in bright environments with diffused light and temperatures above 18 ° C but possibly not too high. Watch the Video