Begonia lamriana ‚Silver‘ – Care
Location & Light
Like most small terrarium begonias, this variety also prefers bright, filtered light without direct sun. Intense sunlight will quickly burn the delicate, velvety leaves, while too little light will make growth sluggish and the silver markings less prominent. Rough guidelines for small houseplant begonias of this type are 40 to 80 µmol/m²/s PAR (PPFD), which corresponds to a DLI of approximately 1.5 to 3.5 mol/m²/day.
Pour
The substrate should be kept evenly slightly moist, without completely drying out or being constantly wet – the fine roots are sensitive to both extremes. It's best to check the top 2 cm with your finger before watering again. Especially after purchase or a change of location, the plant may initially react to the new environment with slightly drooping or curled leaves, which usually resolves itself under stable conditions.
Fertilize
During the growth phase, a very diluted liquid fertilizer is sufficient about every 4 to 6 weeks – with small, sensitive terrarium begonias, it's better to use less than too much. Generally accepted ranges for the genus are a pH of about 5.5 to 6.5 and an electrical conductivity of the irrigation water of roughly 1.0 to 1.5 mS/cm; begonias are generally sensitive to excessively high salt concentrations. If the plant is only on a windowsill in autumn and winter, no more fertilization is needed due to the weaker light anyway; however, with year-round bright plant lamp illumination, fertilization can continue at the normal rhythm for a bit longer.
We consciously alternate between different fertilizers for our own plants – currently including COMPO COMPLETE, Foliage Focus, Liquid Gold Leaf, and Hesi TNT-Complex, supplemented with Hesi Root Complex, Hesi PowerZyme, and CalMag as needed.
Substrate
A fine, very permeable substrate with a high perlite content suits the delicate roots of this begonia best. A pot with good drainage is essential, as the fine roots cannot tolerate constant moisture.
Humidity & Temperature
This begonia is one of the more demanding terrarium begonias and requires consistently high humidity and stable temperatures to truly thrive – a closed or semi-open terrarium is much better suited than an open windowsill. On an open windowsill, acclimatization is more difficult and overall care is more delicate. The ideal temperature range is between 20 and 26 °C, and significant fluctuations should be avoided.
Growth & Form
‚Silver‘ remains pleasantly petite as a compact, small terrarium begonia, making it suitable for smaller display cases or propagation boxes. The silvery shimmering leaf pattern is most striking under stable, humid conditions. For this rather slow-growing variety, the emergence of new leaves is a reliable sign that your care is on point. Growth slows down further with sole window placement in autumn and winter due to weaker light; however, growth remains more consistent under year-round bright plant lamp illumination in a display case.
Good to know
Begonia lamriana belongs to the large group of small terrarium begonias from Southeast Asia, often only described in recent years, which are regularly known in a similar form from the limestone areas of Borneo and neighboring regions. Young plants that have just been acquired often still show minor cosmetic blemishes on their leaves, which grow out over time and are not a sign of permanent damage.
Like all begonias, this species contains oxalates and should be kept out of reach of pets that tend to nibble on plants.