The korean pine (Pinus koraiensis) is a valuable pine tree very adaptable to a wide range of environments and is ideal for an urban setting. This tree is a source of pine nuts that are edible and sold commercially. The wood is very versatile, perfect for furniture making and construction. It is generally used for building railroads, bridges, and paper production.
I. Appearance and Characteristics
Pinus koraiensis is a species of pine known commonly as the Korean pine. It is a relic species of the Tertiary, identified as a rare tree species by the United Nations. It is native to eastern Asia: Korea, northeastern China, Mongolia, the temperate rainforests of the Russian Far East, and central Japan. In the north of its range, it grows at moderate elevations, typically 600 to 900 meters (2,000 to 3,000 feet), whereas further south, it is a mountain tree, growing at 2,000 to 2,600 m (6,600 to 8,500 ft) elevation in Japan. Other common names include Chinese pine nut. The ancient woodland of P. koraiensis on the earth is about 50 million hectares, and China has about 30 million hectares, accounting for 60%. It is a second-class national key protected plant in China. P. koraiensis is a tree species with high economic and ecological value. The official name in Chinese is “红松 hóng sōng/red pine”, because almost every part of it is related to red.
P. koraiensis is a member of the white pine group, Pinus, section Quinquefoliae. Cultivated specimens may grow to about 9 to 15 m (30 to 50 ft) tall, whereas in their native habitat and growing conditions they can reach as much as 30 m (100 ft) or even 50 m (160 ft) in height. It is pyramidal in shape, with younger specimens having ascending branches and older trees having more horizontal branches that reach ground level. The gray or brownish bark flakes off to reveal reddish inner bark. The sapwood is yellowish white, while the heartwood is light yellowish-brown or light reddish-brown. The branchlets and winter buds are also reddish-brown.
The branches are lined with bundles of five blue-green needles, each up to 115 mm (4+1⁄2 in), and bear brown comes up to 150 mm (6 in) long. In Northeast China, a particularly large cone is nearly 200 mm (7.9 in) long and 100 mm (3.9 in) in diameter. The seeds take two years of growth to mature, and the mature seeds do not fall off. The cones release a strong scent that is so irresistible to animals that they help to open the hard cones allowing the seeds to disperse. The nutshells are reddish brown. P. koraiensis is monoecious with different flowers. Male cones are reddish-yellow, mostly clustered in the lower part of new branches to form spikes; female cones are green-brown, solitary or in groups near the top of new branches.
P. koraiensis can live up to 700 years; after 100–200 years of growth, it enters the fruitful youth stage, and after 300–400 years, it enters the fruitful adult stage. The wild P. koraiensis grows very slowly, it takes fifty or even eighty years to bear fruit, and the cultivated P. koraiensis usually takes more than twenty years to bear fruit, but grafted seedlings can bear fruit within a few years.
II. How to Grow and Care
Sunlight
The korean pine can grow in both full sun and partial shade. When placed in a well-ventilated location with sufficient sunlight, the needles will be green and strong. In a hot location with insufficient sunlight, the needles will be weak and will easily turn yellow. Ideally, the plant needs around 5-6 hours of sunlight a day, with good ventilation.
Temperature
The korean pine is mostly native to the northern hemisphere and can withstand many challenging environmental conditions. Tolerant of temperatures ranging between -60 to 50 ℃, making it suitable for hardiness zones 11 and below, this is a plant that grows best in well-drained, deep and moist soil.
Watering
For newly planted seedlings or new plants, water once every morning and evening during hot spells in the summer. Do not water midday, as this can cause root burn or strangle. Water plants according to your individual climate and rainfall in other seasons. For mature plants, only water when they are dry, keeping in mind that these plants are drought resistant. For indoor potted plants, spray water on the surfaces of the leaves once every morning and evening when it is dry. Be careful not to provide excess water – this hinders air circulation in a pot, leading to the rotting of roots and the withering of branches and leaves.
Soil
Korean pine can grow in a variety of different soil types, including bare mineral soil, sandy soil, volcanic ash, calcareous soil, limestone soil, and everything from dusty soil to red soil. Since it is resistant to drought, it will even grow in barren landscapes. However, it grows best in loose, fertile, well-drained, and slightly acidic soil. In the case of too much alkalinity, needles of potted plants will turn yellow and fall, so it is best to use natural mountain soil in pots and containers.
Fertilizing
The korean pine likes fertilizer and should be fertilized frequently, with just a small amount each time, during its growth period. It should be fertilized once a month in late spring, early summer, and fall. A fermented organic fertilizer is most effective for promoting growth.
Generally, do not apply a nitrogen fertilizer, such as urea or human urine, because pine needles already absorb nitrogen from the air, and pine roots are sensitive to nitrogen. You would be best off with a liquid fertilizer, applying this when the soil is dry in the afternoon. Water the plant again after fertilizer application, which will help with root absorption.
Do not use fertilizers that haven’t been fermented, or those with a higher concentration; the former will burn the roots and the latter will lead to the spindling of needles and more root damage, and could even cause the back-flow of sap, leading to water loss and the withering of the plant. No fertilizer should be applied in midsummer, during severe winters, or in the rainy season in the spring.
Generally, plants in gardens should be fertilized twice during the growth periods in spring and fall. Apply an organic fertilizer once before germination in the spring and apply slightly more fertilizer in the fall to promote robust growth. Stop fertilizing after midsummer so as to prevent spindling.
Planting Instructions
Korean pine is best planted in early spring. Ideally, use healthy and vigorous seedlings with soils balls, as this can greatly improve the survival rate. In the case of many lateral roots, the deep main root can be cut. Otherwise, the root system should be protected to avoid damage.
plant in a high, dry, well-drained, and well-ventilated place, with loose soil. In low-lying places with accumulated water, or places with sticky soil, try building a platform or changing the soil before planting. The planting pit should be treated with a basal fertilizer before planting. Newly planted large seedlings should be supported to prevent them being blown down by the wind. Before planting, excess branches should be pruned off. Protect the plant’s shape from damage as much as possible, as this will help to restore growth at a later stage.
Ideally, plant indoor potted plants in the spring, and repot every two or three years in the late fall or early spring. Repotting too frequently will lead to the death of the plant. If the plant is growing weakly, find out the cause of this and change the flowerpot soil, or replant in a larger pot.
Cut back on water before repotting, so as to keep the soil slightly dry. Remove the soil ball from the pot, keeping it whole, and then prune away any old roots from the bottom and sides. Remove some of the old soil from the middle of the soil ball, replace with new soil, apply a small amount of basal fertilizer, and then cover the plant with new soil. Ensure a suitable pot size – a deep pot will easily accumulate water, leading to root rot.
Pruning
For an indoor potted plant, any dead, diseased or damaged branches should be removed. You can then adjust the tree’s shape by pruning branches, pinching buds, and trimming leaves, giving you a better ornamental effect. Prune the plant before all of its needles fall off, so as to obtain a compact shape, richer lateral and side branches, and a better form overall. Pruning should be done during the dormancy period, so as to prevent excess loss of sap and damage to the plant’s vigor.
For a plant in a garden, dense lateral branches should be pruned so as to improve the survival rate. Remove excess lateral branches during the vigorous growth period based on needs, focusing on encouraging the trunk to grow tall and straight. Cut off any diseased or dead branches right away, so as to prevent the spread of pathogens.
Propagation
Korean pine is mainly propagated by seeds or branch cuttage. For family planting or potting, cultivated seedlings or pruned potted plants can be purchased from the market. Pay attention to pests, diseases, and appearance when selecting seedlings.
III. Uses and Benefits
P. koraiensis is a precious tree species with both economic and ecological value. Ecologically, it has the functions of water and soil conservation – its root has a large water storage capacity, which is a “small reservoir” in the eyes of ecologists – and the function of maintaining biodiversity. Economically, every part of the plant can be used. In China, it has a long history of being used in food, beverage, health preservation and medical treatment. The ancients called its fruit “長壽果/longevity fruit”. The traditional Chinese medicine “海松子/sea-pine nut” refers to the seeds of P. koraiensis, which is a nourishing and strengthening agent. At present, the high-tech industry of P. koraiensis has outstanding achievements in the fields of food, health products, medicine, cosmetics and fine chemicals.
The nuts of this tree are edible and sold commercially. It is the most common taxon sold as pine nuts in markets throughout Europe and the United States. The nut oil contains 11.5% of the unusual fatty acid pinolenic acid (cis–5–cis–9–cis–12 octadecatrienoic acid). It “has a variety of physiological effects such as weight loss, lipid lowering, immune enhancement, anti-inflammation, anti-oxidation, enhancement of insulin sensitivity, and anti-tumor metastasis.” Pine nut oil extracted from P. koraiensis nuts has high nutritional value. The oil is also used to make lubricants and soap. The tree is a source of turpentine resin and tannin. The pine needles can be used to extract pine needle oil.
松花粉/Pine pollen is the dried pollen produced by the stamens. It is a traditional Chinese medicine and a traditional Chinese cooking ingredient. It is even used as the name of cakes or drinks, such as “松花糕/pine flower cake”, “松花酒/pine flower wine” etc. “”中国预防医学科学院营养与食品卫生研究所/The Institute of Nutrition and Food Hygiene of the Chinese Academy of Preventive Medicine” has confirmed that pine pollen contains more than 200 nutritional components and bioactive substances, with anti-fatigue, anti-aging, regulating blood lipids, enhancing immunity, and beautifying five major health care functions”. “”国家体育总局运动医学研究所兴奋剂检测中心/The Doping Testing Center of the Institute of Sports Medicine of China” indicated that no ingredients banned by the Olympic Games were found in pine pollen”.
The Korean pine is used as an ornamental tree. It is tolerant of several soil types and thrives in urban settings. It is adapted to climates with very cold winters. There are several cultivars, including the blue-tinged ‘Glauca’ and ‘Silveray’ and the wide-bodied ‘Winton’. The Korean pine is also a good tree species for afforestation in Northeast China.
The wood is versatile and very useful for construction. It is light, with straight grains, and easy to work. It is used for a great variety of products, including telephone poles, railroad ties, bridges, boats, plywood and flooring, furniture, sports equipment, and musical instruments. It is easy to break down into chips, particle board, or pulp for paper. The fatwood used to be the best kindling in the forest area of Northeast China, and now it is a rare object. The carvings or prayer beads made of it are collected or used like precious ancient objects.
