Family: Begoniaceae
Begonia bogneri
Distribution and habitat: Begonia bogneri is a curios species from Begoniaceae family, with short, thin stems, grass like leaves and diminutive flowers. It is a rare species which was discovered in a remote mountainous part of Madagascar in an area called Hiataka which has an average annual rainfall of about 3500mm (140 inch) and a yearly average of 230 rainy days. It grows in deep shade on moss-covered granite cliffs covering the naked rocks among mosses, ferns and sometimes Pothos scandens (Climbing Aroid) at an elevation of 50m (165 feet).
Description: Begonia bogneri is an erect short stemmed tuberous perennial plant. The stem is pink to yellowish up to 4cm (1.5 inch) tall and form a weekly tuberous base, tuft-forming. The leaves have leafstalks which is not readily discernible and are crowded on the short stem. They are alternate stipulate with stringy appearance about 2mm (0.08 inch) thick and 15cm (6 inch) long, like greengrass and margins with small irregularly spaced spicules. Like other species within this genus, the Begonia bogneri has male and female flowers. The inflorescence is 15cm (6 inch) tall with one or two male flowers and one female flower. The flowers are pink and the male flowers have 4 petals, while the female flowers have 6 petals. The flowers are usually produced in early and mid summer.
In cultivation the plant develops into a clump consisting of a number of stems all arising from the one tuber-like body.
This species is easily recognized by its unusual grass-like leaves. In nature the plants are probably deciduous, while in cultivation, the leaves are evergreen under right light conditions.
Houseplant care: Begonia bogneri has a slow growth rate. It is not an easy species as house plant or terrarium plant. In a terrarium this plant enjoys high humidity and temperatures. As a house plant it must be watered properly, though the soil must be kept wet but not overwatered. Prune out the dead stalks or fallen blooms.
Light: If grown in a greenhouse under natural light Begonia bogneri tends to become dormant in winter and will drop its leaves, but applying artificial lightining can prevent this resting period.
This plants may be grown in contained atmosphere (terrarium) under horticultural fluorescent lights. They require particularly bright light, therefore they need to be closed to the centre of the light where light levels are most intense. Timers may be used to provide 14 to 16 hours of light a day. This can be reduced temporarily to 12 hours a day for two months in early winter to encourage flower production.
Alternatively, plants grown under natural sunlight on a windowsill will often perform best when provided with a south facing position in winter and est-facing one in summer. However, care should be taken if the plants are grown in glass containers to not overheat them by placing them on windowsill.
Temperature: In cultivation Begonia bogneri is usually grown in an enclosed grass container because it likes a very humid atmosphere. It also prefers a relatively cool position and performs best within a temperature range of 18-21C (65-70F). Terrariums should be placed in cool places. Additionally the temperature inside the terrarium can be reduced by setting the lights to come on only at night time when conditions are usually cooler. A fan can also remove any excess of heat produced by the lights.
Rise the air humidity around the plant when not grown enclosed in a terrarium. Begonia bogneri will need relative humidity around 60 percent.
Water: Use tepid water for these plants. Begonia bogneri tubers should be allowed to dry out between waterings.
Plants grown in contained atmosphere will need less watering then those in other situations. The only way to determine when to water is to touch the surface of the growing material to feel how moist it is. Water only when it become dry. Rain or distillate water is preferable. Sealed containers will need watering only a few times a year, making it great for people which are traveling. If a particularly dense build-up of condensation occurs on the inside of the container soon after watering, it means that too much water has been added. Use paper towers to remove the excess of water and leave the lid off for a few hours to correct the problem.
If it is grown mounted in sphagnum moss mounted on a piece of cork, never allow the sphagnum moss substrate to become saturate for this will cause the small tuber to rot. To solve this problem, suspend the mounted plant over a large storage tank of water inside a greenhouse. This arrangement provides the plant with necessary humidity without saturating the growing medium.
Feeding: Fertilising Begonia bogneri grown in terrariums is rarely necessary. Otherwise, apply standard liquid fertiliser once a month to actively growingBegonia bogneri plants.
Potting and repotting: Begonia bogneri should be repotted once at intervals of 2 years. Do not overpot this plant, otherwise excessive moisture may accumulate in the potting mixture and cause the roots rot. Use an open potting mixture containing lots of chopped sphagnum moss and perlite.
This species is also occasionally grown in sphagnum moss mounted on a piece of cork.
Also this plant can be grown in terrariums. The growing medium should be composed of chopped, long-fiber sphagnum moss and a small amount of perlite. Prepare the sphagnum for the mix by immersing it in boiling water to sterilize it, allow it to cool, then cut it with scissors into roughly 2.5cm (1 inch) pieces. Blot the wet sphagnum with a paper towels to remove any excess of water before mixing it with perlite. Place a thin layer of charcoal, about 0.5cm (0.2 inch) in the bottom of the terrarium to absorb soluble salts and other impurities before they have the chance to damage the roots. Add a layer of 2.5 to 7.5cm of the prepared growing medium mix. This medium will be enough moist, no additional water after planting is needed. Check annually the pH of the growing medium. If the pH has fallen below 5.8, ground limestone may be gradually worked into the growing medium until the pH is raised to correct level.
Propagation: Propagation of Begonia bogneri is topically achieved by dividing the plant or taking cuttings of whole leaves or section of leaves. Place the cuttings in an open rooting mix, such as four parts sphagnum to one part of perlite. If the tiny leaves, either whole or in part are planted in moss, they eventually produce new plants.
Problems:
Pythium rot root attacks the roots and stem bases of adult plants and cuttings. Affected plants at first will have a slightly wilted appearance, followed by yellowing their lower leaves. As the disease progress, the roots and stems turn black and musky, leading to the death of the plant.
Treatment: The use of sterilized potting mixture and use of appropriate fungicide will control this disease.
Botrytis blight will produce gray moldy patches on leaves, stems and duds.
Treatment: This disease can be managed by improving the air circulation and plant hygiene by removing and destroying dead and dying leaves ans flowers. Use a suitable fungicide.
Powdery mildews produce unsightly white powdery patches on leaves, stems and buds.
Treatment: Manage this disease by restricting watering to morning so that water unwillingly splashed on leaves will quickly evaporate. Improve the air circulation around the plants. Severe cases may be treated with adequate fungicide.
Bacterial leaf spot will produce water-soaked areas on the leaves that are surrounded by yellow rings. It may cause leaf drop and, in some cases, associated stem rot may occur.
Treatment: Once the disease is present, remove and destroy any affected leaves or stems and spray the plants with a bacterial leaf spot treatment.
Rhizoctonia crown rot will be detected by the presents of brownish mould spreading from the soil to the infected stem base, a condition that will eventually lead to the collapse and death of the stem. This fungal disease appear only on plants that have been damaged or stressed by high temperatures or poor growing conditions.
Treatment: Maintenance of hygienic conditions and good cultural practice should prevent fungal growth. Fungicide sprays are also available.
A variety of viral diseases can attack plants causing symptoms like yellowing the leaves, pale yellow rings or spots, leaf malformation and stunted growth.
Treatment: Always use sterile potting mixture and treat insect infestations to prevent viral disease. Destroy all affected plants.
Mealy bug can be a common pest of these plants.
Treatment: If infestation is localized, remove insects by wiping affected areas with a cotton swab dipped in rubbing alcohol or dipping the plant in a solution of soapy water and alcohol.
A number of tiny mite species can be problematic for these plants. Infested leaves are yellow speckled and, if the infection is severe, may be covered with wool like substance on their undersurface.
Treatment: Control these mites with a suitable acaricide.
There are two kinds of microscopic, worm-like creatures parasite to these plants: leaf nematodes and root nematodes.
Treatment: The best form to control is to destroy affected plants. In open garden avoid replanting begonias in contaminated soil. In case of potted plants, infestation may be prevented ans controlled by routinely using sterilized potting mixtures and washing the plant pots.
Scale insects may feed on plants.
Treatment: If infestation is localized, remove insects by wiping affected areas with a cotton swab dipped in rubbing alcohol or dipping the plant in a solution of soapy water and alcohol.
Both the adults ans larvae of two kinds of weevils feed on plants.
Treatment: Insecticides are capable of controlling these insects, but if they are inside the cavities of the plants, they will not be killed. To fully exterminate them, systemic insecticide are needed.
Whiteflies infest the under-surface of the uppermost leaves and if disturbed fly rapidly around the top of the host plants.
Treatment: Successive sprays of insecticidal soaps or white oil will eradicate whiteflies infestations. Coverage of leaf undersides is important.
Availability: Begonia bogneri it is relatively new discovered plant - in 23 January 1969 by Josef Bogner. It is a species known to had very limited distribution in wild and as a result it is a plant with limited population. Unfortunately, this species is one of the few Madagascan begonias have ever introduced into gardens and they remain rare.
Uses and display: Begonia bogneri is a very rare terrarium begonia. Lovable pink flowers which have a long inflorescence make the Begonia bogneri even more appealing for your terrarium or windowsill. Alternatively it can be grown mounted in sphagnum moss mounted on a piece of cork.
SUMMARY:
CHARACTERISTICS:
Foliage green
Features flowers
Shape bushy
Height: under 6 inch
PROPER CARE:
Watering in active growth period moderately
Light bight filtered
Temperature in active growth period min 18oC max 21oC (65-70oF)
Humidity high
Hardiness zone: 11
