Begonia, one of the most known indoor plant, a genus of 900 species, more or less fleshy annuals, herbaceous perennials, evergreen shrubs and climbers, including some succulents and epiphytes is the perfect choice if you like color and variety in your indoor plants. Begonias are prized equally for their flower as well as their showy leaves. They offer a huge range of foliage texture and color as well as color of bloom. With lots of variety, begonias are popular in flowerbeds, for hanging baskets, as container plants, and for indoor houseplants.
Begonias don’t tolerate cold temperatures, do not like frost in the spring or fall, most of them are frost tender, only a few are half hardy and are grown either as annuals or dug up in the fall, stored and replanted in the spring or grown as indoor plants that can be taken outside over the summer. Set them out in containers, hanging baskets, or your flowerbed after all risk of frost has past. Most houses, especially those with forced air heat, where the humidity is too low, are not suited for growing begonias indoors, but most begonias can be grown in your home, if you are careful enough to provide each with its particular requirements.
Begonias may be divided into 7 informal groupings based on their growth habit and differing cultivation needs: cane-stemmed begonias, rex-cultorum begonias, rhizomatous begonias, semperflorens begonias, shrub-like begonias, tuberous begonias (including the Tuberhybrida, Multiflora and Pendula begonias) and winter-flowering begonias.
Cane-stemmed begonias: are woody, fibrous-rooted, evergreen perennials with the slender, bamboo-like stems. As the plants age, the canes sometimes turn black, giving the appearance of bamboo. Cane-stemmed begonias are among the easiest type of begonias that you can grow. Showy hanging clusters of red, pink or white flowers open in spring and summer. Some cane-stemmed begonias flower all year long. These begonias also have beautiful foliage beside their attractive flowers. Most leaf surfaces are glossy, but some have a dull surface. Leaf color ranges from pale to dark green to mahogany. This type of begonias will not tolerate continuous, direct sunlight and tend to shed their lower leaves if they are overwatered. To keep the plant in a good shape, cut back overlong canes to 2 or 3 buds in spring or early summer. When not pruned, cane-stemmed begonias may reach 10 feet in height. It is a good idea to cut back overly-long stems in the spring or early summer to encourage new growth at the base. The tall, bamboo-like stems may require staking. This type of begonias can be propagate by tip or stem cuttings.
Rex-cultorum begonias: are mainly evergreen, rhizomatous perennials that offer remarkable foliage, where bright and unusual shades of green, pink, red, silver, purple and gray combine to make bold patterns on the leaves. These begonias are less spectacular in flower than the flowering types of begonias, but they have the advantage of keeping their leaves all year round. There are also trailing types that are used in hanging baskets. They can be trickier than most other begonias - try to maintain them at an evenly warm temperature, at an optimum of 21-24 Celsius degrees (70-75 F). This type of begonias like to be grown in bright indirect light. Bright light deepens the re coloration of the leaves while lower light levels enhance the metallic sheen of many cultivars. If the light is too low, leaves will revert to one color. Minimize rhizome rot by immersing containers in water and let the soil dry slightly between waterings and increase the humidity, if possible. You can propagate this type of begonias by seed, rhizome sections or by leaf cuttings. To propagate by leaf cuttings use a clean, sharp knife to cut a large, healthy leaf from a mature plant than make small cuts, about 2-2,5 cm apart, across the main veins on the underside of the leaf. Lay the leaf face up on moist potting soil holding the leaf against the soil with small stones. Cover the pot with a plastic bag. Remove the plastic covering when you see that new plants are forming at the leaf cuts. When the plants are large enough to be handled easily, they can be separated and potted individually.
Rhizomatous begonias: are usually evergreen perennials that flowers in winter or early spring. They like bright filtered light with shade from hot sun and an optimum temperature of 19 Celsius degrees (66 F). to minimize the risk of rhizome rot water them by immersing the pot into water. This type of begonias can be propagate by seed, leaf cuttings or by sections of rhizome. These begonias send down roots along their stems, making them easy to propagate by cuttings.
Semperflorens begonias: are bushy, usually compact, fibrous-rooted, evergreen perennials and have an abundance of dainty flowers in shades of pink, red or white. These begonias are more tolerant of sun but not direct overhead sunlight, will flower best in partial shade and are frequently used as bedding plants or for color in a hanging basket or windowbox. Keep them just moist and well-ventilated in winter at 10-15 Celsius degrees (50-59 F). Those begonias can be propagated by seed or basal cuttings.
Shrub-like begonias: are mostly bushy and sometimes succulent, evergreen perennials, grown mainly for their leaves which are hairless, hairy or warty, with glossy or matte surfaces. In winter maintain a minimum of 17 Celsius degrees (63 F) and provide bright winter light to enhance the color of the foliage. Glaucous and hairless species tolerate higher light levels than the ones with hairy leaves but all need shade protections from hot sun in summer. To keep this type of begonias in full shape it is better to pinch out the growing tips twice during the growing season. They can be propagated by seed, or by stem, tip or leaf cuttings.
Tuberous begonias: are mostly bushy, tuberous, perennials that are dormant over the winter period and are grown for their foliage and flowers. These begonias produce the largest and most spectacular flowers of all the begonias and will bloom all summer long, then go dormant in the fall. Tubers can be saved over the winter and than replanted next spring. At the end of the flowering season stop watering and cut off shoots. You can harvest tubers in the fall after a killing frost. Remove all foliage and the stem at the soil line. Carefully remove tubers and shake off excess soil. Store in a cool basement or any dry place with temperatures between 5-7 Celsius degrees (41-45 F), where you can surround tubers with very lightly moistened peat moss. Dust the tubers with with fungicide to prevent rot. Check periodically during the winter for signs of tubers drying or rotting. Drying occurs with warm and dry storage conditions. Bulbs rot when conditions get too warm and moist. Next spring replant tubers, hollow side uppermost, in free-draining potting compost at 16-18 Celsius degrees (61-64 F). Under glass provide bright filtered light and good ventilation, reduce humidity when the plant is flowering and pinch out small female flowers to prolong flowering. You can propagate this type of begonias by seed, basal cuttings or stem cuttings of sideshoots.
If you want to have an early start for your begonias than try planting tubers in mid- to late-winter. Place the tubers in peatmoss or a soil mix containing one part soil, one part peatmoss and one part vermiculite. Cover with about 1 cm of the mix and put them in a warm place. Keep the soil moist at all times and use a complete fertilizer. Grow the plant in an east or north window during the winter and early spring months. Do not give tuberous-rooted begonias full sunlight. Turn plants about once a week to get a symmetrical plant. This is important since only a little light will be available in an east window. You can take begonias in the outdoor garden after the danger of the last frost in the spring has passed. Do not bury plants any deeper in the garden soil than they were in the pots.
Winter-flowering begonias: are low-growing, compact, bushy, usually fibrous-rooted, evergreen perennials that wear flowers in shaded of red, pink yellow, orange and white. They like bright filtered light with the maximum available light over the winter at an optimum temperature of 15-20 Celsius degrees (59-68 F) and with relatively low humidity and good ventilation. Those begonias can be propagated by basal cuttings.
Some general considerations can be made, that can be suitable to all types of begonias. The first consideration is where exactly are your begonias going to live. The best light for growing indoors is to use fluorescent lighting. This will give you the most control over the amount of light your plants get. You can use a simple shop light with ordinary cool white tubes. A more expensive, but more useful idea if you plan to have a larger collection of begonias is to buy a light stand. The lights should run about 14 hours a day. The light tubes should be just a couple of cm above the tallest plant on the shelf.
If you have natural light in your rooms that would be better for your plants and you should take advantage of it. Most begonias will grow in nearly every window location except probably a north window. Some plants in terrariums may grow fine in a north window, as long as you use some artificial lightening in addition. If your plants start to stretch, this is a sigh that they need more light and if they are stunted and burning then they need to be farther from the window or moved to a window with less light.
The second consideration is the soil mixture that you are going to use for potting your begonias. Begonias hate to be over-potted or over-watered. Don't move begonias to a larger pot until roots have filled the current pot. If you see that a begonia soil never seems to dry out, it is probably because it is in a too large pot. Move it into a pot of the size that fits its rootball, after you have removed all the soggy wet mix.
For growing indoors begonias you should use a soilless mix, composed of peatmoss with additions of perlite or vermiculite. You can make your own potting mix from 2/3 peatmoss or a peat based mix with 1/3 perlite. When you will have to transplant a begonia use an all-purpose potting mix combined with 30 percent bark. Make a hole in the potting mix and insert the plant into the hole, push the soil firmly around the begonia to remove air pockets.
The third consideration is about the watering. Water moderately in growth period and sparingly in winter and make sure that the soil is never wet or waterlogged. Allow the soil surface to dry out slightly and then water. Don't use saucers unless you fill them with pebbles so that the plant doesn't sit in water. You can use bottom watering, but always empty the water of the saucer after a couple of hours.
The forth consideration is the humidity that you are going to offer to your begonias. Although begonias don't like wet soil, they do like air humidity. You can achieve enough humidity for many types of begonias by simply misting them daily. You can also use a humidifier.
The sixth consideration is fertilization, and like any other plant that are actively growing, begonias will do best with regular fertilizing. Apply a balanced liquid fertilizer at alternate waterings when the plants are in full growth.
The seventh consideration is propagation. Different type of begonias have different methods of propagation. For the one that are propagated by seed, sow the seed at 21 Celsius degrees (70 F) as soon as they ripe and for Tuberhybrida and Semperflorens hybrids in early spring. Root stem, tip, or leaf cuttings in spring or summer in a propagator placed in partial shade. Root basal cuttings from tuberous begonias in spring and from winter-flowering begonias in early summer.