Sea buckthorn (Hippophae rhamnoides) is a robust, fast-growing deciduous shrub in the family Elaeagnaceae, native to cold-temperate regions of Eurasia. Due to its deep and branched root system, it tolerates drought very well. Sea buckthorn leaves, fruits, and seeds are used in the food and cosmetics industries, in traditional medicine, in veterinary medicine, as animal fodder, and for ecological purposes. It enjoys great popularity in permaculture and is used as part of edible forests and orchards.
A remarkable property of sea buckthorn is that its roots live in symbiosis with bacteria that fix atmospheric nitrogen, thus increasing soil fertility. This means sea buckthorn does not require nitrogen fertilization. Roots also utilize mycorrhizal fungi to convert insoluble minerals from the soil into more soluble groups, thus providing the plant with mineral nutrients.
Plant Description and Flowering
Sea buckthorn is a beautiful shrub with narrow, silver-green leaves, covered with bright orange fruits in autumn, and is easy to grow. It reaches a height of 2–4 meters. Its branches can be thorny or thornless, depending on the variety. It is a dioecious plant, meaning male and female flowers grow on separate plants. The ratio of male to female plants is important for maximizing fruit production. One male (pollinator) and five to six female plants is recommended. It usually blooms at the age of three, from March to May, and the flowers are pollinated exclusively by the wind. Male flower buds are two to three times larger than female ones. The male flowers also have a different color: they are yellowish, while the female flowers are greenish-silver.
Fruits
Vegetatively propagated sea buckthorn begins to bear fruit three years after planting. The fruits, called berry-like drupes, ripen from August to October and remain on the bushes for a long time, even through the winter. They grow in clusters densely attached to female shoots. They are oval, 5–10 mm long, glossy, and yellow, orange, or red in color. The dense, orange flesh has a sour, sweet-tart to sweet flavor and contains a kernel. The pulp and seeds contain triglyceride oils with significant medicinal value. There are two sources of oil in sea buckthorn: the seeds, which contain 10–15% oil, and the pulp surrounding the seeds, which contains 29–48% oil.
Location, Soil, and Fertilization
Sea buckthorn is a light-loving plant; if planted in the shade, it will not bear fruit and will gradually die. The recommended planting distance is 1–2 x 3 m. The male bush, the pollinator, should be planted within 10 meters of the female bush. Sea buckthorn grows and bears fruit best in well-drained, sandy-loam soil with plenty of organic matter and moisture. Soil reaction is not limiting, although it performs best at a pH of 6 to 7. The soil should have sufficient moisture for the roots of newly planted plants. Plants must be well anchored in the soil after planting and can then survive even extreme drought. In summer, when development and fruit growth are intense, sea buckthorn trees should be provided with sufficient water. Irrigation can significantly influence fruit size. Like other crops, sea buckthorn requires a sufficient amount of nutrients in the soil to produce a high yield of high-quality fruit. It responds well to phosphorus and potassium fertilizers.
Pruning
To ensure a regular, bountiful harvest, both educational and rejuvenating pruning of the sea buckthorn is necessary.
We want to grow a low shrub up to 2 meters tall with 3-5 strong skeletal shoots. In the first year after planting, the one-year-old shoot is shortened to 3-4 buds. A strong, 70-90 cm tall, vertical shoot will grow, the tip of which is cut off the following spring. From this shoot, high-quality side shoots will grow at a height of about 40-60 cm, forming the skeletal crown of the shrub, which will then also enable a bountiful harvest. Sea buckthorn heals pruning wounds very slowly, so always apply balsam to the pruning wound.
From the third year onwards, weak and dry branches are removed, and from the 4th-6th year onwards, root suckers are removed. In 5-7 years, the sea buckthorn will have a fully developed crown. During this growth phase, it is necessary to gradually rejuvenate the sea buckthorn by pruning older branches and replacing them with young ones after 2-3 years. No dry branches should be left on the twigs. Stronger and more vigorous male plants can also be left in tree form.
New Varieties
It's no longer true that sea buckthorn is just a thorny shrub with small, sour fruits, suitable only for winter bird food and for planting in devastated soils as a reclaimed tree. Modern cultivated varieties are smaller, have larger fruits, an improved sweet flavor, many are thornless or only slightly thorny, and their fruits hang on longer stems, making them easier to harvest.
Hand-picking
The fruit stems of most older varieties hold tightly to the branches and are difficult to break. Therefore, sea buckthorn berries are harvested by hand at botanical ripeness, when the fruits reach their characteristic varietal color. At this point, they still have a firm skin and flesh and do not crack during harvesting. Overripe fruits are difficult to harvest and lose a significant portion of the nutrients for which we cultivate them.
Freezing Harvest
The simplest harvesting method is to cut the shoots with the fruits and freeze the entire branches. The frozen fruits can then be easily separated from the branches by striking them against a hard surface. However, we must remember that by cutting the fruit-bearing branches from the bush, we prevent it from bearing fruit the following year. If we want to harvest fruit every year, we need to plant at least two fruit-bearing female bushes and, of course, a pollinator. We cut one bush one year and another the next. This way, each bush bears fruit once every two years.
The fruits are either eaten fresh or frozen and processed into various products. Pressing the sea buckthorn berries produces juice with a 60 to 85% fruit content. Valuable sea buckthorn oil is extracted from the seeds. Other products include sea buckthorn liqueur, wine, compotes, jams, marmalades, syrups, and candied fruits.
Chemical Composition
Sea buckthorn leaves, berries, and seeds have high nutritional value and are a natural concentrate of vitamins and other biologically active substances. They contain vitamins C, B1, B2, B6, folic acid (B9), beta-carotene (provitamin A), tocopherols (vitamin E), and vitamin K1. Bioactive substances include bioflavonoids, essential fatty acids, choline, inositol, beta-sitosterol, serotonin, betaine, coumarins, triterpenic acids, succinic acid, and pectins. The pulp contains 12.5–17.5% dry matter, up to 13% sugars, 1.5–4% organic acids, and 0.5% minerals, the most important of which are calcium, manganese, potassium, magnesium, and several trace elements. The vitamin C content is 10 times higher than that of an orange. Sea buckthorn has no rival among plants in terms of its content of tocopherol (vitamin E), beta-carotene (vitamin A), and phylloquinone (vitamin K).
Sea buckthorn is a medicinal plant
The fruits, seeds, leaves, and bark of sea buckthorn have medicinal properties. Sea buckthorn is a source of many valuable substances important for health, beauty, and vitality. At the beginning of ripening, the fruit contains the most vitamins and biological components. The juice from the pulp has a bactericidal effect. It stimulates digestion and has a positive effect on the body's overall resistance to infections. Both the leaves and bark are an important source of calcium, manganese, and magnesium. Magnesium plays an important role in vascular and heart health and reduces the risk of arteriosclerosis. The fruits are used for general weakness and during convalescence. A decoction of the fruits is used for skin diseases. A decoction of the seeds is used as a laxative. Sea buckthorn oil is most commonly used in medicinal practice. The oil, pressed from the seeds and peels of the fruit, contains a large amount of vitamins, especially beta-carotene and tocopherol, which have a significant impact on fertility and the course of pregnancy. The oil possesses excellent regenerative properties, stimulating tissue growth in damaged skin and hair growth. It is used to treat eczema and hemorrhoids. Sea buckthorn is also a well-known and highly valued product in cosmetics due to its positive effects on skin and hair. Sea buckthorn ointments regenerate tissue in cases of frostbite and burns. The fruits, leaves, and bark are dried and used to make a medicinal tea.