Begonium family. This is a type of rhizome begonia that is grown for colorful leaves. Their flowering is quite modest, the leaves are incomparable, but there are difficulties in care, which are often insurmountable for an ordinary flower grower.
The parent species Begonia rex (translated from Latin - "king") was discovered in India in the state of Assam, introduced into the culture in 1850, and was, of course, beautiful: dark green leaves with silver-gray spots. Immediately, its enhanced hybridization with other rhizome (rhizome) begonias began, so all modern begonias belonging to the Rex group are hybrids (in fact, this group of begonias bears the name of one of the parents), although the correct name is Begonia Rex-hybrid or Begonia Rex Cultorum. Many of the common begonia rex have been known to the world for centuries: Begonia rex 'Abel Carriere' was obtained in 1878 and is still grown today. Subsequently, hundreds of varieties appeared. But at a certain point, hybrids began to be attributed to the Rex group, in whose genetics there was no original parent (wild) species begonia rex, which fundamentally distinguished this group. They just turned out to be extremely similar (Brad Thompson). It should also be noted that Rex begonias were used in crossing with Upright Joined Rhizomatous begonias, and beautiful hybrids were obtained, which, like all Kings, have spectacular leaves.
In general, according to the classification of all types of begonias, the Rex group belongs to rhizome (rhizome *) begonias, but due to some features (initially - origin, later due to the peculiarities of care) they are distinguished separately, separately. Most plants are low, reaching a maximum of 1-1.5 m, with a lying, creeping, eventually hanging stem, which is a rhizome. Traces of old, already dead leaves are clearly visible on it. Leaves on long petioles. The shape of the leaf can be: simple rounded, oblong, oblique, snail-shaped, cirrus (slightly dissected or deeply dissected, star-shaped). The edges of the leaves are whole quite rarely, more often dentate or wavy. Leaves, petioles and "stem" are covered with dense hairs of various colors (whitish, yellowish, reddish, etc.). On the surface of the leaf, the hairs are very short, dense, which makes the leaves appear velvety. Hairs are rarer and longer on stems and petioles.
The variety of color of the leaves is striking: a different combination of colors, patterns, marbling of the pattern, in some royal begonias the leaves have a metallic silver sheen. The dimensions of the bush and leaves can be from miniatures, when the leaf is about 5 cm in diameter, to large, with leaves about 20 cm in diameter.
Caring for the royal begonia
Temperature
Begonia Rex is relatively thermophilic, in summer they prefer the usual, room temperature, the one that weather conditions dictate to us, but they do not tolerate the heat (above 28 ° C). Optimal temperatures for growth are 21-26 ° C during the day, and 18-20 ° C at night, i.e. daily temperature differences should be 5-6 ° C. Begonia collectors have noticed that in regions with hot climates, begonias grow better on low stands with wide pallets filled with moist gravel. The stands are located at a level of 30-50 cm from the floor, or right on the floor, here the temperature is slightly lower, this is noticeable on hot summer days.
It is possible, and even necessary, in the summer to expose begonias to fresh air - in the garden, on the balcony or on the veranda, but it is necessary to bring them into the house at the end of summer, and not in the fall, like many other houseplants. In many countries with a warm climate, begonia rex is grown as an annual garden plant (only for the spring-summer season), put right on the street, but the temperature never drops below + 5-6 ° C. We grow this beauty in Russia in order to preserve plants as long as possible, therefore, given the tenderness of Rex begonias, do not leave them outside if the temperature can drop below 12 ° C. They do not tolerate these begonias and cold drafts; when ventilated or placed on the street, they need to be protected from the wind.
In winter, it is advisable to keep royal begonias in cooler conditions than in summer, optimally 16-18 ° C, at least 15 ° C. In this case, the air humidity should be 45-50%, not higher.
Lighting
The general requirement, like all deciduous begonias, is bright diffused light. Rex begonias respond well to some direct sun in the morning or evening. In spring and summer, shading from direct sunlight is required from 11 to 16 hours. The best option is to place on the east or northwest windowsill.
On the northern windows, begonia rex also grows very well if these windows are not shaded by anything from the street (trees, buildings). However, these general recommendations are very arbitrary, the light requirements depend on the varietal characteristics. Some varieties grow perfectly in rather shaded places, others only in well-lit ones. The fact that the light is not enough will tell you the change in the color of the leaves, or rather the loss of brightness and intensity of the pattern on them.
If the light hits the begonia constantly on one side, the plants begin to form a one-sided crown, lean towards the window. This is especially noticeable in spring with a sharp increase in sunny days and a rapid growth rate. In this case, you need to turn the pots with flowers weekly, doing about a quarter of the rotation of the pot.
Watering
Royal begonias are watered moderately, with drying of the earth, so that between watering the earth is almost dry. Royal begonias do not tolerate complete drying of the earth, but they tolerate even worse constant dampness, prolonged drying of the earth. Some hybrids and varieties are especially sensitive to overflow, easily rot. The most common care error is trying to compensate for the lack of air humidity with more frequent irrigation, and this cannot be done. The quality of irrigation, so to speak, depends on the correctness of the selected substrate (quickly absorbs and quickly dries, breathes). The water should be soft, better boiled. Avoid water on the leaves, especially in cold weather.
Fertilizing
Royal begonias are supplemented only in spring and summer, weekly with fertilizers for ornamental and deciduous plants at a dose of 1/4 of the recommended. Begonias are sensitive to excess fertilizers, especially those where there is too much nitrogen, choose those fertilizers where there is slightly more nitrogen than potassium and phosphorus or all components are the same amount (NPK 20-20-20). Unfortunately, I did not find special fertilizers for royal begonias, obviously we simply do not have them in Russia, of the same that are on sale, Pokon is suitable for ornamental deciduous plants with NPK 8-3-5, or Pokon universal with NPK 7-3-7, it is quite possible to use fertilizers for orchids, in the dose recommended by the manufacturer, for weekly top dressing
There are special fertilizers for begonia, for example, the Merry Flower Girl Fertilizer 2 in 1 Multiproduct for Violets and Begonia with NPK 5-5-9, or the Begonia Miracle Garden with NPK 4-5-6, but they are not intended for royal begonias, but for blooms. In addition, the Garden of Miracles fertilizer has a high alkalinity: its pH is 8-10, it is completely unsuitable for begonias in general, and even more so for begonias. Therefore, be careful when reading labels, if it is written that for begonias, first read the composition, and not blindly believe the manufacturer.
Royal begonias with dark leaves are the most shade-tolerant.Air humidity
Optimal humidity 50-60% constantly. There are among begonia rex, especially miniature varieties, more demanding, they need 60-70% humidity. The problem of begonia is that for all their exactingness to high humidity, they are hypersensitive to diseases that develop with increased dampness. Not only the ingress of water on the leaves, but also simply stagnant moist air around the plants, contribute to the appearance of gray rot on the leaves. Therefore, it is important to ensure good air ventilation, to avoid crowding of plants, although there is a great temptation to put pots with beautifully deciduous begonias together, in a dense group.
How to transplant begonia
Royal begonias love slightly acidic soil, pH 5.0-6.0. But the main requirement for the structure of the soil is that it must be very loose, airy, rich in humus and dry out quickly, no longer than 2 days completely. Not suitable for planting begonia Rex only garden land from the beds, and pure peat. Pure leaf land is more suitable (collected under last year's leaf litter somewhere in a linden park). There can be several options for soil mixtures:
- 2 part of leaf, 1 part of peat, 1 part of coarse river sand (or vermiculite).
- 2 part of peat land, 1 part of coconut substrate (from briquettes), 1 part of coarse river sand (or vermiculite), 1 part of pine bark.
- 2 parts of universal soil, 1 part of vermiculite, 1 part of sand, 1 part of pine bark.
As you can imagine, sand and vermiculite are baking powders. Pine bark also loosens and further acidifies the soil. And even with the addition of loosening components, it is necessary to ensure that the substrate in the pot does not cake, periodically loosen it with a thin sharp stick. And when a salt crust forms on the soil surface, it is imperative to replace the top layer of the earth and soften the water for irrigation.
Royal begonias grow well in shallow and not too spacious pots, if the pot is large, the soil will dry out for a long time - this contributes to the development of pathogenic flora and rot decay. But it is better to transplant begonias annually, into fresh land, and into the old pot, if the root system has not grown too much.
Some miniature begonia rex can be grown in wide open aquariums, in fact, all conditions for them are similar to the requirements of orchids. Also air humidity, the same requirements for light and irrigation, even for fertilizers and pots. When growing Rex begonias on wide trays of water, and even more so in aquariums, it is possible and even necessary (!) To use pots with drainage holes on the bottom and sides of the pot. Basically, you can grow royal begonias in wicker (plastic) baskets, or make holes yourself. Perhaps I will surprise someone with such recommendations, this is my personal experience, but it helps to avoid rooting, bacterial spots and other diseases. In nature, begonia Rex grow in the surface layer of the earth, which is a leaf litter, branches and branches of trees - this is a very loose substance. Many begonias lead semi-epiphytic and epiphytic lifestyles.
I am against adding sphagnum moss to the royal begonia soil as it takes a long time to dry, absorbing moisture too abundantly, but you can spread wet moss between pots to increase humidity. And against the cultivation of Rex begonias in clay pots, the soil dries up quickly enough in them, but some of the roots stick to the unglazed sides of the pot, and the hole at the bottom is usually the only one and small. In plastic pots, you can always slightly squeeze the sides (walls), thereby loosening and airing the soil.
Breeding begonia royale
Begonia Rex, like all rhizome begonias, easily reproduce vegetatively. In nature, this happens with scraps of a leaf, pieces of rhizome, if it breaks off, a whole leaf, etc. The only thing that is needed for the success of rooting: high humidity, constantly evenly humid substrate, rather loose and air.
Salt deposition on the soil surface is too hard water. Ideally, use rainwater.The mixture for rooting a handle (leaf with a piece of rhizome), leaf or part of a leaf may consist of equal parts of peat and vermiculite, the main thing is that the soil does not dry out. It is not necessary to close with a bag, cap or glass, but it is necessary if the room is warm and the soil dries quickly. In this case, place the plate with the sheet in the bag, but do not tie the edges of it, but simply raise it high and straighten it. No growth stimulants are required.
The only thing that can prevent rooting is severe drying of the soil or vice versa, excessive dampness, causing the growth of putrefactive microorganisms and mold. It is not necessary to bury a piece of rhizome or part of a leaf in the ground, it is important here that there is only a small contact with the wet surface of the earth, no more. You can press a leaf or riza with a fruit skewer, toothpick or paper clip. A thick piece of rhizoma is placed horizontally on the ground and slightly buried in it, no more than half the thickness of the rhizoma, i.e. the upper part remains on the surface.
Re-establishment of old begonias
Begonia Rex very often increase the risoma, and at the same time they lose the lower leaves from the wrong care (too hot in winter, lack of light), of course, first of all, it is necessary to find out why this is happening, and in the future to correct the mistakes. But at the moment the plant needs to be re-rooted. Otherwise, it can fall out of the pot and be badly damaged. Usually, such specimens have a fluffy, well-leafy shoot top, but it is undesirable to cut it off and put it in a jar of water (like the top of a dracena or aglaonema). Usually such "cuttings" quickly rot in the water. You can root it in the usual way by sticking it into the ground, but at the same time you will most likely lose the beautiful upper leaves (they will not have enough food and moisture).
Therefore, in such cases there is only one way - an air branch. You can't call it any other way. If the length of the exposed lower part of the rhizome allows, then you need to bend the top of the begonia to the ground and fix it with an arched piece of wire (a braided aluminum wire bent with the letter U will do). When the crown is rooted and the roots grow enough (5-8 cm), it can be cut off and transplanted if necessary. The remaining stump must be cut as close to the ground as possible, and it will also give a new growth.
To propagate part of the leaf, it is necessary to cut it so that each part has a large central vein.The challenges of growing begonias
There are and will be problems with Begonia Rex. This culture is also demanding, as are orchids. No wonder they are singled out in a separate group among decorative-deciduous begonias.
First of all, the problem is the extreme susceptibility to bacterial rot and fungal disease in conditions of high humidity. And they need this humidity first. But even if we place begonias on wide trays of water, and miniature ones in a terrarium, there remains a problem - air movement. It practically does not exist in the apartment, and the one that appears during ventilation creates a draft. The lack of ventilation is not scary when the air is dry. But if it is very humid, in stagnant air, mold fungi and bacteria multiply several times more intensively. In orchidariums, for example, to avoid such problems, they arrange a fan, but not one.
Therefore, the success of growing royal begonias in an apartment largely depends on the ability to maintain high humidity and at the same time painlessly ventilate at any time of the year. Excessive humidity, by the way, is destructive to plants at low temperatures.
The second problem that occurs with Begonia Rex is the inability to pour soft water. No matter how you defend and boil, a salt deposit still forms on the surface, spots on the leaves. What to do? First, contact the pet store and ask for a means of preparing aquarium water for fish settlement. These funds soften water, and in a matter of minutes. But few people use them for indoor flowers, but in vain. Second, reconsider the fertilizer you use to water the begonias. Among them there are many completely unsuitable, as I wrote above: alkaline, with a large dose of nitrogen. On some, the composition is not even indicated. Only fertilizers that acidify the soil, with trace elements in chelate form, are suitable for us. At worst, it is safer to use fertilizers for conifers, azaleas or orchids than to take dubious ones for deciduous and deciduous or supposedly "for begonias" poured from the same barrel as for ficuses or palm trees.
Begonium pests
A beautiful composition, but these are usually short-lived - begonia will grow out of this vase too quickly. In addition, there are no drainage holes in it.Thrips - these pests are little noticeable on variegated leaves, found when gray or brown spots appear on them, irregular in shape, along the edges, in the center. Some of the leaves turn yellow. Black drops or crumbs, about 1 mm in size, are visible on the surface of the leaf. In this case, it is impossible to spray with insecticide, you can only water with a systemic drug: a solution of actara or confidor. As a last resort, use an insecticide spray. Trips are a flying pest, so look for signs of infection on other plants in the house.
Mealy worms: often appear on begonias, and can lead to the complete death of the plant. They hide in the husk from stipules in the lower part of the rhizome, intensively sucking out the juice. This becomes noticeable when the leaves fly around en masse, and the worms form entire colonies. Signs - white shaggy, as if cotton, lumps at the base of the petioles of the leaves. Examine the risoma carefully if the plant suddenly starts to dry. You need to fight the worms with the same insecticides - watering with actara solution (1 g per 1-1.5 liters of water). On the leaves themselves, worms usually do not appear (in extreme cases, hide at the very base of the leaf plate on the bottom side), so the rhizome itself can be treated with insecticide in a spray.
Begonium diseases
Gray rot - appears on begonias with high air humidity, prolonged drying of the soil (for several days), especially under cool conditions. Rot (soften, actually limp) parts of the rhizome, the lower parts of the petioles of the leaves. Gradually, the gray fluffy mycelium of the fungus becomes noticeable at the sites of decomposition.
Downy mildew is a fungal disease that usually appears as a result of a genetic predisposition in some varieties of begonia. Aggravated by high humidity, poor air ventilation. It begins with the appearance of yellowish or dirty gray spots, which are noticeable rather on the lumen of the leaf, or on the back of the leaves. On velvet begonia leaves, they are noticeable when necrotic tissues become extensive. Spots are rounded, formed anywhere in the leaf blade.
Bacterial rot is actually no different from gray rot, only mycelium of the fungus is not formed. And outwardly - the same rotten moist spots on pieces of rice, on petioles and the leaves themselves. The reason is the same waterlogging of the soil, its long drying out, lack of ventilation, excessive fertilization.
Fungal and bacterial diseases can be fought with the help of fungicides (xom, oxychom and other copper-containing drugs), as well as create more suitable living conditions (loose soil, proper watering, ventilation, sufficient illumination, optimal air humidity commensurate with temperature).
* Rhizome is a creeping root-like stem of some plants, most often underground, but can also be aerial. Usually grows horizontally, above-ground reese - lying, or creeping on the surface of the earth (low above the ground). New shoots and roots of the plant are formed from the rice in a sexless way. Underground rhizomes differ from the roots in that they have buds, nodes and scale-like leaves.