Ornamental or utility value
sunny to semi-shady
neutral to slightly acidic
The birch fig (Ficus benjamina) is often called “Benjamini” or simply “Ficus” and is one of the most popular indoor plants. There are indeed hundreds of Ficus species, some of which, such as the rubber tree (Ficus elastica) or the violin box tree (Ficus lyrata), are also common as houseplants. However, if one speaks of his “ficus” among houseplant fans, it is usually clear that this refers to the birch fig, which is native to the subtropical and tropical regions of East Asia, Oceania and Australia. Their distribution area extends from Nepal over India, Bangladesh and South-China to Malaysia, in addition there are natural continuances on the Solomon Islands and in North-Australia. In the meantime, however, the ficus is widespread in the tropics and subtropics around the globe as an ornamental plant and in many places has gone wild as a so-called neophyte. In warm countries, it is often planted as a small street tree or as a hedge, as it is very easy to cut and is therefore ideal for contour cutting. Also as Bonsai the tree is cultivated therefore frequently, however predominantly small-leaved weaker growing varieties like ‘Nana’ or ‘Natasja’.
The botanical species name benjamina (biblical: “the youngest”) does not come by chance, because with a growth height of about ten metres and a width of eight metres, the birch fig is a rather small representative of the genus Ficus. The leaves are also relatively small and the young branches, covered with a smooth, ochre-yellow bark, are strikingly thin and clearly overhang at the tips. As a free-growing tree, the plant can reach a trunk diameter of 50 centimeters in its native country and forms a densely branched broad-oval crown. The conspicuously light grey bark, which peels off in places on older trees, and the elliptic, long-pointed leaves probably inspired botanists to use the German name Birkenfeige (birch fig). As with most tropical plants, the foliage is evergreen and the leaves have a remarkably smooth, shiny surface. They are alternate and the new leaf buds are strikingly thin, long and pointed.
As a Ficus owner in the United States, it is very rare to be able to enjoy the blossom – only in the bright, warm winter garden do the houseplants sometimes form Flowering in the leaf axils. The small spherical inflorescences consist of separate sexual flowers and, because of their spherical appearance, look like fruits. However, they changed into such only if they are approximately schlehengroß and take on an orange-red color sloe-large into such, however. Botanically speaking, these are so-called aggregate fruits which, like all parts of the birch fig plant, are slightly poisonous. Latex allergy sufferers should not bring Benjamini into their home. Like the rubber tree (Ficus elastica), which is cultivated as a natural rubber supplier, a white, sticky latex-containing milky sap also escapes from the birch fig when bark is damaged. In addition to varieties with different leaf sizes, there are now a large number of decorative forms with white-green or yellow-green foliage. Depending on the variety, the leaves are white, yellow or light green marbled, veined or edged.
Location and substrate
Ficus benjamina as a typical forest edge and clearing tree needs a bright, 22 to 28 degrees warm, but not too sunny location during the vegetation period. Above all with the colorful-leaved types, it occasionally comes to Blattverbrennungen in the bulging midday-sun if they are held for example in the summer under open sky on the terrace. Nevertheless, they need more direct sunlight than the green-leaved species to colour the colourful leaves well. In winter, the temperature should be lowered to around 18 degrees Celsius – so the plants can cope better with the lower light supply. The ficus sometimes reacts somewhat sensitively to changing site conditions such as strong temperature fluctuations, draughts or Soil cold and sheds part of its leaves. Here, too, the colorful-leaved varieties are somewhat more problematic than the green-leaved varieties. Also with lack of light it usually comes to leaf fall. Birch figs, on the other hand, tolerate dry heating air relatively well.
Commercially available houseplant soils are not so well suited as substrates: they are usually much too rich in humus and therefore not structurally stable in the long term. The manufacturers are rather sparing in compiling the earth formulations with the important mineral components – these are comparatively expensive depending on the starting material and cause higher transport costs due to their high weight. House plant professionals therefore mix their soils themselves by enriching the purchased house plant soil by about a third to a half with mineral additives such as construction sand, weed-free garden soil, lava grit and clay granulate. The ficus also needs a corresponding mineral portion, which may be a little coarser. The optimum pH value for the ficus is between 6.5 and 7.
Watering and fertilizing
If you consider the site and soil conditions, a ficus is basically very easy to maintain. Although you should regularly supply your Benjamini with water during the vegetation period, always allow the bale surface to dry thoroughly before watering the ficus again. You can determine the right time with the so-called finger test: If the soil still feels slightly damp at the top of the pot, you should wait until you have soaked it. A coaster under the planter is also recommended, as birch figs are sensitive to waterlogging. In the cachepot, excess water often goes unnoticed. For watering, it is best to use room-warm rainwater or stale tap water that is not too rich in lime.
From March to September, you should fertilize your ficus about every two to three weeks with a liquid green plant fertilizer, which is administered according to the dosage recommendation on the bottle with the watering water. If possible, use a branded product, because studies show again and again that cheap fertilizers from discounters sometimes have major shortcomings with regard to their nutrient composition. In winter, fertilization every six to eight weeks is completely sufficient.
Cutting and repotting
If your birch fig gets too big, you can cut it to the desired size with scissors at any time. But be careful with the sticky latex: it can not only cause allergies, it can also ruin your clothes and floor. Pruning is best done outdoors on the lawn, then shower the plant with room-warm water from a large watering can and allow the latex to dry for a few hours before bringing its ficus back into the house.
It is best to convert a newly purchased birch fig into better soil immediately, as the substrate in the sales containers is usually of very poor quality. Otherwise the Ficus can be converted depending upon size and growth strength every two to four years in March into a somewhat larger pot. The diameter of the vessel should not exceed six centimeters.
Further care tips
Two to three times a year a handwarm shower is good for the ficus. Place it in the bathtub and wrap the pot ball in foil so that it does not wet. Then spray your Benjamini with lukewarm water to remove the dust from the leaves. In addition, you should occasionally spray the tree with room warm rainwater from all sides and turn the pot on the windowsill regularly so that it cannot grow one-sidedly towards the light. Variegated varieties sometimes form single shoots with monochromatic green leaves. These must be cut out of the crown immediately, as they are more vigorous than the other branches and the colourful leaf decoration would otherwise fade further and further into the background over the years.
It is very easy to multiply the birch fig with cuttings. Usually, two to three shoot tips, which have previously been defoliated at the bottom, are placed in a pot of growing soil and covered with foil to keep the humidity high. In the case of the green-leaved species, however, rooting in water glass on the windowsill without any evaporation protection also works very well. As soon as the first roots appear, the cuttings are planted in potting soil and trimmed slightly so that they branch well and form a dense crown.
Diseases and pests
The most common pests on the ficus are scale insects. One often comes on them only through the leaves stuck together with honeydew on the track, since they know to camouflage themselves very well. Infested plants should be isolated immediately from other indoor plants and treated with a rapeseed oil preparation such as “Pest-free Natures”. Alternatively, you can use plant protection sticks during the vegetation period, which are simply inserted into the soil and whose active ingredient reaches all parts of the plant with the sap flow. All further pests and also illnesses hardly play a role with the robust birch fig.
Whether potted plants such as oleanders or indoor plants such as orchids: The scale insect infests the most diverse plants. René Wadas, a herbalist, will give you his tips on pest prevention and control: Production: Folkert Siemens; Camera: Fabian Primsch; Editing: Dennis Fuhro; Photo: Flora Press/Thomas Lohrer
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