First of all, Begonia Rex loves warm rooms in which the temperature does not fall below 18 degrees, and even better - always above twenty. In addition to the winter period, when, on the contrary, acclimatization of the plant goes better in a cool room (up to 16 degrees). And although in the tropics and subtropics, where they come from, thunderstorms and storms are frequent, avoid blowing rooms with begonias by drafts, otherwise the flower may die. All of the above conditions would be perfectly matched glazed loggia, or a balcony with insulation.
Location also relates to the factor, how lit room. The heroes of our article are very fond of sunlight, otherwise their foliage becomes a pale shade.
Description and photo
In Europe, the Rex begonia appeared in the second half of the XIX century as a guest from the hot southeast Asian tropics and was instantly taken for breeding by growers and breeders. To this day, they managed to bring dozens of new species, among which is the royal begonia group. 
Professional classification identifies this variety as a rhizome variety. Creeping root system, thick and fleshy, turning into a fleecy stem, from which large filigree leaves with long pubescent petioles and forming a closed bush 30-45 centimeters in height recede.
There are versions of this variety and lower, inferior in size to the older brothers in half.
In the course of breeding and breeding hybrids, varieties appeared with splashes, leaves twisted in a spiral with a catchy scarlet color and contrasting lines. 
Humidity and temperature
Humidity is very important for this room culture, especially in hot weather. With large succulent leaves, the royal begonia evaporates much more fluid than it compensates for the rhizome.
To increase the humidity, you can use an air humidifier, an atomizer with a fine spray, and also install pots with plants in summer over pallets, on the bottom of which you should put wet pebbles, a rag and periodically add liquid there.
Lighting in the room
The flower prefers a lot of diffused light. This is due to the origin of the plant from the places where it was constantly covered with the crowns of trees. The royal species does not like direct hit by the sun, the leaves dry out and lose their brightness.
It is recommended to put the flower on the shelf, cabinet or table, which is distant from the source of direct sunlight, or darken the room with a curtain of tulle.
Begonia substrate
Special root system needs a certain soil. Creeping roots, called the rhizome, are located above the substrate, weak branches are separated from them, which require light, breathable soil for breathing, moisture and nutrition. 
A mixture with a weak acid peat that adores the royal flower will be suitable. The composition of the mixture: half is occupied by peat and one-sixth capacity of humus, sheet or sod land, baking powder (vermiculite, perlite).
Division of roots
For reproduction, you should remove the begonia from the occupied container directly with the roots and ground, so as not to damage anything. Next is the removal of old stems, stalks and large foliage. Extra soil is removed and the rhizome is carefully stratified into smaller parts.
The presence of shoots or buds in each of them is obligatory. Wood ash is used to process the cuts. Divided roots are placed in a special soil, which can be purchased at a flower shop.
Abundantly watering seedlings, they are placed in places with good illumination and room temperature. 
Cuttings (leaves)
This is the most common method to propagate begonias. It is used because of a number of advantages:
- ease of execution,
- getting quick results
- preservation of all varietal traits.
Next, cut off all the foliage, except for one or two upper leaves. If they are too large, it is worth cutting them a little.
For rooting, cuttings are placed in water at room temperature. Suitable only soft water, the use of hard or cold will destroy the future plant. 
The room should have a temperature of 19-21 degrees Celsius and good illumination without direct sunlight on the plant.
The use of transparent containers is recommended for continuous monitoring of the state of the cuts.
When rotting is found in the cuttings, new sections are made and fresh water is poured. Replanting into suitable soil occurs when the two-centimeter roots grow.
For rooting cuttings in the soil, it is recommended to buy a special soil mixture in a specialized store. As an alternative, you can use a mixture of peat and sand in proportions of 1 to 3. For successful germination, it is necessary to ensure the air temperature in the region of 23-25 degrees Celsius.
The capacity for this procedure is chosen small, so that not only the root system develops, but also flowering occurs. 
We recommend treating the lower section with the help of root-growth stimulating drugs. The shoot is placed in moist soil to the leaves. Then the container is covered with a transparent cap, in the role of which may be a glass jar or a plastic bottle, you must not allow the plant to touch it.
The correct microclimate should manifest itself in the form of condensate on the surface of the cap. Daily airing will lead to additional hardening of the flower. After the germination of new leaves the plant is no longer covered.
Propagating begonia with seeds is not an easy task. This is justified only by preserving the varietal qualities of the flower. Seeds are purchased in specialized stores. The grains are very tiny, so they are covered with soluble material. 
The best time for sowing is the first two months of the calendar year in order to get an already strong flower by the autumn cooling.
If planted with the arrival of spring, we will get later flowering, and since April, they do not advise planting, because the root system does not have enough time to develop, the tubers will be too small, which can lead to the death of the plant.
For planting seeds suitable transparent plastic box. The bottom is covered with a half-centimeter drainage layer and a drain is made. It is recommended to mix the sand with the ground in equal proportions. Also suitable is a homogeneous substrate, in which leaf soil, peat and sand are related as 2: 1: 1.
The soil for some time before sowing is slightly moistened. Grains spread to the surface and slightly pressed down, but not covered with soil. The lid is made of clear glass or film, maintaining the required level of humidity. 
Sprouts will die even with a slight drying of the soil. The temperature of the room should be 20-25 degrees Celsius. Use a spray or drip irrigation to prevent small seeds from being washed off.
Shoots will appear in one to two weeks depending on the properties of the acquired seeds. After this is carried out the rearrangement of the capacity with seedlings on the window sill, where a little cooler. A large number of bright scattered rays of the sun will allow stretching and strengthening of begonia sprouts.
If the weather is cloudy, be sure to use artificial light. To do this, you can build an external frame of conventional light bulbs. Place a thin object under one edge of the lid so that the drops of the condensed liquid flow to the side, not fall out on the shoots and not destroy them.
Air tank once a day for half an hour. 
After three weeks, small shoots should sprout true leaves. They should be carefully seated every couple of centimeters and placed in small plastic containers. The soil used is the same as when sowing.
Keeping the shape of the roots, sprouts are planted in moist pits and watered a little. This procedure is repeated several times with a further increase in disembarkation, each time increasing the distance by several centimeters.
Recommend twice a month to make special fertilizers to stimulate root growth. After three months from the moment of disembarkation, the begonia can be transplanted into pots or to permanent places in the garden.
