Iron Cross Begonia gets its name from the dark-colored cross shape on its leaves. These plants are often grown as houseplants because they are not cold-hardy. They occasionally grow small flowers but are usually grown for their unique foliage.
I. Appearance and CharacteristicsÂ
Begonia masoniana, the iron cross begonia, is a species of plant in the family Begoniaceae, native to southern China and northern Vietnam. It was originally described from cultivated plants of unknown origin and was only much later rediscovered in the wild.
It is a rhizomatous perennial begonia growing to 0.5 metres (20 in), bearing large, asymmetrical, textured green leaves covered in reddish hairs, with a prominent dark brown pattern in the centre of each leaf, reminiscent of the German Iron Cross. It produces small white flowers in erect panicles, but is cultivated mainly for its foliage effect. In temperate regions it must be grown under glass, or in a completely frost-free environment. Not to be confused with the similar looking species Begonia variegata, from Vietnam. Although sometimes (incorrectly) considered a Rex begonia, this species is classified in the related section Coelocentrum.
This plant has gained the Royal Horticultural Society’s Award of Garden Merit.
II. How to Grow and Care
Sunlight
Iron Cross Begonia prefers bright filtered sunlight. Only a few species can tolerate strong sunlight. It’s sensitive to light and leaves are liable to be burned under strong sunlight. If planted indoors, placing it next to windows is recommended so as to let it receive sufficient scattered light during the day. The best exposure time is more than 4-6 hours. If planted in the garden, it can be in the shade under trees without very dense leaves, so that it can receive sufficient scattered light.
Most begonias are long-day plants that thrive in plenty of sunshine. Their flowering time will change with the length of lighting time and will be significantly delayed when lighting time is short and the night-time temperature is lower than 21 ℃. However, it should be noted that the Rieger begonia is a short-day plant and only the stems and leaves grow during long-days (more than 14 hours a day). It blossoms only during short-days in winter.
Temperature
Iron Cross Begonia is native to warm and humid subtropics and tropics and grows wild in the fertile and loose leaf mold when summer approaches. They are not cold-resistant and prefer moist habitat. Some varieties may enter dormancy in autumn. The suitable temperature for them to grow is 19 to 24 ℃ and in winter not lower than 10 ℃. The leaves are susceptible to freezing, while their rhizomes are more cold-resistant. It grows rapidly in warm and humid conditions, with lush stems and leaves and bright and colorful flowers.
Watering
Iron Cross Begonia prefers humid environments, so it should be watered regularly to keep the culture media moist. In high temperatures, if not watered sufficiently, the stems of the plant are liable to fall and the leaves are apt to wither. For outdoor or pot planting, as long as it is in the plant’s growth season, water the plant when the soil feels dry to the touch, water the soil until it is totally wet, and then drain excess water. Note that the watering amount should not be too much, as water accumulated in the pot can cause root rot.
The varieties of begonias with ornamental leaves are in vigorous growth in summer. Besides regular watering, it needs to be sprayed several times a day to keep the relative humidity at 56%-60%. In winter, iron Cross Begonia grows slowly, and the amount of watering can be reduced accordingly. It can be watered once every 3-4 weeks until it grows again in spring.
Soil
Iron Cross Begonia grows well in a well-drained mixture of sandy soil, clay and loam, with a suitable pH range of 5.5-6.2. However, iron Cross Begonia will grow better in soilless environments than in conventional soil. Planters can buy ready-made soilless culture media, or mix 2/3 peat moss or peat with 1/3 other soilless culture media such as vermiculite, bark and perlite to provide a slightly acidic and well-drained media for the plant.
Fertilizing
To increase nutrition, iron Cross Begonia prefers properly diluted fertilizers or fertilizers mixed with a little compost and peat moss. After flowering, it is necessary to start applying fertilizer regularly, but not too frequently. Adding liquid fertilizer about once a month is the recommended frequency, and you can choose to buy different kinds of fertilizer according to the needs. Iron Cross Begonia is sensitive to excessive fertilizer, and high concentrations of fertilizer can damage the leaves. Fertilizer should not be applied frequently in late fall and winter because it does not grow steadily during this period, even in dormancy.
Planting Instructions
Sowing is recommended to be done after frost in winter because iron Cross Begonia grows best in warm environments and a gradually warming climate allows it to thrive. Iron Cross Begonia seeds are small, and need to be evenly mixed with fine clean sand and sprinkled on the media when sowing. During its growing process, patient waiting is needed, and exposure to direct light should be avoided. Usually, it will sprout when midsummer comes.
Pruning
When the flowers begin to turn brown and die after blooming, withered flowers and leaves should be pruned right away to promote new growth. Removal of withered flowers and leaves will prevent them from falling into dense bushes and rotting later, thus causing disease. At the end of the flowering season, it is necessary to remove the branches and buds with poor growth such as yellowing, dryness and thinness. After flowering, tuberous begonias will store all the nutrients in the bulb for the next growing season. plants can be pruned in cool and mild fall. When pruning, it’s better to remove the apical buds in the long lateral branches and remove the first one or two healthy shoots to promote more branches.
Propagation
Iron Cross Begonia is usually propagated by cutting. Stem cutting can be carried out at room temperature all year round, but it has the best effect in late spring and early summer, with fast rooting speed and high survival rate. The tops of plump stems are often used as scions. It is better not to use flower buds as scions.
Leaf cuttings work best in spring and fall. It can also be carried out at room temperature or in winter, but rooting speed is relatively slow. The cuttings should be fully developed mature leaves. Leaves that are too tender or aging heal and root slowly and the probability of forming mature seedlings is low.
Cuttings should be placed in well-drained containers, and a mixture of vermiculite, peat and perlite can be used as the culture media. Keep it in a bright and warm place, away from direct sunlight and ensure that the soil contains a small amount of water to keep it moist.
Overwintering
During cold winters, potted iron Cross Begonia should be transferred indoors or in greenhouses for maintenance. For open-field plants, appropriate warming measures should be provided, such as covering with 5 cm of peat moss, tree leaves, sawdust or straw, or covering plants with fabrics or cardboard boxes. Do not let coverings oppress plants.
III. Uses and BenefitsÂ
Iron Cross Begonia is a very striking plant that is generally chosen for its beautifully patterned leaves, tolerance for shade, and ability to return year after year from its rhizome. Though it is most often placed in moveable containers, it can also be used as a ground cover in shady areas, or as part of a shade garden.
IV. Harvesting and Storage
Iron Cross Begonia doesn’t have long straight stems, so it is not usually used as cut flowers. According to personal preference, the top flowers can be collected for flower specimen pressing or other purposes. They can be collected at will as long as it is the growing season, but don’t take away too many stems and leaves.
