This genus includes about eighty species of shrubs or small trees originating in New Zealand and Asia; in nature they can reach a few meters in height, while the plants grown in the apartment remain below 120-150 cm. As ornamental plants in general, only 6-7 species are cultivated, very appreciated for the showy foliage, P. fruticosa is also cultivated as bonsai. The stems are erect, smooth and woody; from each node branch off numerous branches, often also erect, which carry leaves of various types, depending on the species: they can be roundish or finely divided, of various colors, from light green to reddish brown, and also variegated. In general, plants grown in containers do not produce flowers or fruits; specimens of some years should preferably be pruned every year, so as to maintain a compact and rounded shape.
To have a luxuriant growth of the Polyscias filicifolia, place in a very bright place, also exposed to the sun during the coolest hours of the day; in general they can withstand temperatures close to 7-10 degrees, but they develop best if cultivated at 18-20 ° C even in winter, so they should be kept in the apartment. Being plants of tropical origin, they love mild temperatures and a good humidity to develop at their best.
Water Polyscias filicifolia regularly throughout the year, taking care to wait for the soil to dry slightly between one watering and another; in the periods of the year when the air is very dry it is advisable to vaporize the leaves every 2-3 days. In winter it is better to reduce irrigation.
Throughout the year, add fertilizer for green plants to the water used for watering, at least once a month, without exceeding the fertilizer doses. If left too long without water, they tend to lose their leaves, which sprout readily by supplying adequate water.
To place the Polyscias filicifolia specimens, it is good to use a peaty, fertile and light soil, very well drained; the root system of these plants is not very developed and the roots are fragile and thin, therefore it is not advisable to repot them often. Intervene with the repotting when the plant has reached the dimensions for which the roots tend to suffer inside the container. It is good to repot the plant in the spring period.
Check that the soil where the Polyscias filicifolia are planted does not allow water stagnation, a factor that can cause the onset of rot.
The multiplication of this genus of plants takes place by cuttings, with great ease, in spring or summer, by rooting the cuttings produced in water or soil, kept constantly humid. The ideal soil for rooting the cuttings is formed by peat and sand. It is good to place the cuttings in a sheltered place where the temperature is around 22 ° C.
Polyscias filicifolia: Pests and diseases
If excessively watered or in the presence of too compact soil, the Polyscias may be affected by root rot. Aphids can also attack this kind of plant and, if not opposed, can create significant problems. To eliminate the problem it is good to provide a treatment with systemic products, which, when entering the lymphatic process of the plant, are absorbed by insects. Even the red spider may attack the plant; to verify its presence it is useful to check if there are crumpled leaves. To eliminate them, if the attack is not massive, it is good to intensify the vaporization with water, since this type of parasite is intolerant.