Pinus parviflora bonsai are coniferous evergreen resinous plants of the family Pinaceae and the genus Pinus. This bonsai tree is also known under the common names Japanese white pine, Ulleungdo white pine, Five-needle pine, Goyo matsu and Hime komatsu.
Etymologically, the Latin word pinus comes from the Indo-European words “pit” which means “resin” and “pinu” which means “to be fat, swell”. The specific epithet of the Latin name, parviflora, means “with small flowers.”
This conifer plant is native to Korea (Ullung island) and Japan, where it grows in mountain regions. In Japan, Pinus parviflora is one of the most favorite species of pine, grown both as bonsai and ornamental garden trees. It has been cultivated in Japan and China for centuries. Popular dwarf cultivars of the White Pine are Zuisho, Kokonoe and Myojo.
In the West, the plant was first described in the nineteenth century by the German botanists Philipp Franz Balthasar von Siebold and Joseph Gerhard Zuccarini. This pine tree was introduced to England in 1861.
Pinus parviflora is an upright tree. In its natural habitat, the tree can grow up to 25 meters tall. It has a very attractive appearance due to its wide, dense and conically-shaped crown. Mature trees develop broad and flattened canopies. This massive tree sometimes splits into two or more stems. This tree is often described as graceful, elegant, tough and whimsical, with outstanding ornamental features.
This pine has soft, five-centimeter-long, needle-like leaves. They are fragrant and grow in bundles of five and are green-blue on the top and blue-white on the bottom side. They can stay on the tree for 4–5 years. The bark is grayish and deeply fissured or peels off into scales. It is thin and can be damaged easily. The flowers are yellow, inconspicuous and not showy. They flower in spring. The cones are typically 4–7 cm long, and have broad and rounded scales. They are brownish-red in color and can stay on the tree for up to seven years. The seeds are approximately 1 cm long and contain a vestigial wing.
This guide provides the foundations of Pinus parviflora bonsai tree care.
How Long Does It Take to Grow Pinus parviflora Bonsai?
How long it takes to grow a bonsai tree generally depends not only on the species but the selected bonsai style. Growing a good Pinus parviflora bonsai specimens (such as a root over rock bonsai) requires patience and can take well over ten years. This plant’s growth rate is considered rather slow.
How to Plant and Grow Pinus parviflora Bonsai
Propagation
Pinus parviflora is considered a variety that is a bit difficult to germinate. Since the plant does not grow easily from seed, and the specimens which do germinate tend to be less vigorous, this method of propagation is rarely used. In rare cases when this method is applied, the seeds need to be soaked overnight in a glass of water. This needs to be done in winter. All seeds which float on the surface should be removed, as they will not geminate. The candidate seeds are then placed in low temperature for a long time, before they are sown.
It is also very difficult—if not impossible—to strike cuttings of Pinus parviflora.
Most white pines used for bonsai are propagated using grafting technique. For this purpose, best is to use a one-year-old, 3–4 mm thick pine shoot. In the first step, the scion for grafting is trimmed using a sharp scalpel into a flat chisel shape. In the second step, a slanting cut is made in the root-stock to a depth of about 4 mm. The scion is inserted in such a way that its cambium and the rootstock perfectly match. In the third and final step, the scion is firmly wedged into the root-stock, and the two are tied together using raffia or special grafting elastic. To secure the joint, it can be covered using grafting wax. Following the procedure, the plant should be kept in a cool shed for a few months. While watering the plant, extra care is needed, so that no water penetrates the joint.
Air layering is another method by which this plant can be successfully propagated. Some bonsai enthusiasts consider this method particularly convenient, since fairly thick branches can be propagated in a very short time.
Temperature Requirements
Pinus parviflora is a hardy plant in most temperature zones. However, this bonsai tree will not thrive indoors.
During the summer, Pinus parviflora bonsai should be kept in a bright outdoor location. Ideally, it should have access to full sun throughout the entire day. However, the plant is tolerant to moderate shade. If the tree receives insufficient sunlight, its needles grow longer—a trait not desirable among bonsai specimens.
During the winter, the plant needs to be given a period of freezing, in order to maintain its health. It should remain outside, but sheltered from icy winds in an unheated shed or a greenhouse. If the specimen is grafted, then it should be protected from cold, especially from temperatures below -10°C.
Soil and Watering Needs
Pinus parviflora bonsai needs a well-draining soil. The plant can tolerate various soil types, including clay, loam, sand, acidic and poor soils. It has moderate drought tolerance and high aerosol salt tolerance.
It needs to be watered according to the season. In summer, the plant should be watered moderately, and in winter sparingly. In winter, the compost has to remain moist, but it should never be waterlogged. It is acceptable to allow the surface of the compost to dry before the next round of watering. Permanent moisture is bad for this plant, but high humidity is beneficial.
Feeding
Before the plant has developed new needles, it can be fed with nitrogen fertilizer. In the next stage, a high nitrogen plant food should be provided. Small quantities of rapeseed fertilizer can be applied throughout the growing season. Chelated iron should be applied twice or thrice annually. The feeding should stop in autumn.
How to Care for Your Pinus parviflora Bonsai
Pinus parviflora bonsai is considered an easy-to-keep bonsai. It be trained in different single-tree styles. However, the most popular is the informal upright style. Most commonly seen styles for this species are freely upright (Moyogi) style, the strictly upright (Chokkan) style, and the inclined (Shakan) style.
The cultivation for commercial purposes typically involves grafting on to rootstock of Pinus thunbergii (the Japanese black pine), because this provides strength and vigor to the tree. When Pinus parviflora bonsai is grown on its own roots, the plant also develops a yellow tinge.
A good Pinus parviflora bonsai tree is characterized by strongly growing trunk, and compact branches with healthy foliage distributed close to the trunk.
Pruning, Pinching and Wiring
In late spring, pinching can be done using the fingers. In every cluster that contains 3–5 candles, the strongest one or two can be removed.
The longest branches can be pruned in mid-autumn. The cutting should be done above a needle cluster. New shoots should be either shortened or completely cut off during mid-summer. The young, inner shoots should be let grow and strengthen for a couple of years before they are cut.
There seems to be no consensus regarding the ideal time for wiring. Some experts suggest that the best time to rewire the Pinus parviflora bonsai is summer and autumn. Others advise wiring in spring, and then leaving the wires on until the branches have set. Since this bonsai. Has very flexible branches, the wire usually has to remain long, so that the branches do not immediately return to their original position. Removal of the wire is necessary if it begins to bite into the bark.
The tree produces resin which acts as a natural cut paste. Therefore, no sealing is required.
Repotting
Repotting of Pinus parviflora bonsai should be done on average every three to five years. Small and young bonsai specimens can be repotted in early spring, once every 3–4 years. Larger and older specimen can be repotted every 5–6 years.
It is recommended to use a coarse gritty soil that contains approximately a quarter of organic matter or Akadama. Some experts recommend not to remove more than 25 percent of the old soil, and use a mix of loam, sharp sand and leaf mould.
It is also recommended to use a strong, deep and rectangular pot, since the plant depends on a deep root system that supports their dense canopy. Specific to pines is their symbiotic relationship with a fungus that grows in their root ball. Without this fungus, the tree might die. Therefore, the plant should never be bare-rooted, and not much of the root mass should be removed during the repotting.
Pests and Diseases
Like all pines, Pinus parviflora is susceptible to aphids, caterpillars, mealy bugs, spider mites and scale. The bonsai can also suffer from fungal diseases and root rot due to extra watering. Any sign of a pest or a disease should be immediately acted upon, since the tree often dies quickly. It is recommended to spray adelgids with an appropriate insecticide.