Coniferous Pinus
Description
Characteristic Features of Pine
Pine (Pinus) is a genus of coniferous evergreen trees or shrubs in the pine family Pinaceae. In the wild, Pines often make a dense forest. Pines cultivated as ornamental trees are used both in groups and in single plantings.
The origin of the Latin name of the genus is still unclear. According to one version, the word "pinus" derives from the Celtic "pin" (mountain, rock), which refers to the habitat of the plants in the tropical climate. According to another version, the name is traced to the Latin "pix" (resin) referring to resin (gum) produced by pines. The resin, along with essential oil, needles, and buds, is widely used in medicine.
The root system of Pine is strong and deep, the trunk is straight and covered with bark, the branches are whorled, and the crown may be of various shapes and colours, depending on the species. Pines can grow from 50 centimetres tall in dwarf species to 50 metres tall in wild species at the age of 70.
Pines have two types of shoots, long shoots with scaly brown leaves and short shoots with needles (2-5 pieces per fascicle) 5-10 centimetres long.
The fruit is a cone with nuts that ripen only on the 2nd or 3rd year after pollination.
Mainly dwarf trees and woody shrubs are used for landscaping. They do not only decorate gardens and parks with their graceful looks but also refresh air and boost human energy. Pines look great close to any trees, in particular the juniper, spruce, fir, oak, and barberry. This plant is also suitable for single plantings.
The genus Pinus comprises about 110 species found in the Northern Hemisphere, both hardy representatives native to the temperate and northern climates and heat-loving plants occurring in southern countries.
The most common tree is the Scots Pine (Pinus silvestris). It has a straight trunk up to 40 meter tall and dark green needles with two needles per fascile. In the gardens, the following ornamental varieties are widely cultivated: 'Alba' (grey-blue needles); 'Aurea' (a shrub up to 1 metre tall, with a rounded crown and golden needles); 'Waterera' (about 4 metres tall, with a conical crown and bluish needles); 'Compressa' (up to 2 metres tall, with a columnar crown and short needles); and 'Nana' (a low bush reaching only 50 centimetres tall, with straight bluish-green needles).
The following species are also common:
Macedonian Pine (Pinus peuce) has a pyramidal crown, deep green sticking needles (5 pieces per fascile), and long pine cones. Its dwarf variety 'Nana' is commonly used in landscaping.
Jack pine (Pinus banksiana) has an oval crown, green shoots that eventually turn brown, twisted light green needles, and curved cones. The most attractive variety is 'Annae' combining both green and white/yellow needles in a single tree.
White Pine (Pinus strobus) has a pyramidal crown, wide branches, and bluish-green needles (5 needles per fascile). There are very popular ornamental varieties 'Fastigiata' with a columnar crown; 'Pendula' growing up to 2 metres tall, with weeping branches that reach the ground; a shrub-shaped 'Nana' with short needles; 'Umbraculifera', a low shrub with an umbrella crown; 'Aurea' with golden needles, 'Nivea' with silvery-white needles; 'Glauca' with blue needles; and 'Variegata' with variegated needles.
Mountain Pine (Pinus mugo) is a branched shrub with brown scales on the top of the trunk, short dark green needles, and middle-sized grey-brown pine cones. The most attractive cultivars are 'Brevifolia' up to half a metre tall, with a barrel-like crown and deep green needles up to 1.5 centimetres long; 'Winter gold', a dwarf variety up to 50 centimetres tall and 100 centimetres across with a spherical crown and golden green needles (2 needles per fascile); 'Gnom', about 2 metres tall and across, with a spherical crown and green needles; 'Kokarda' with two yellow spots on each needle; 'Compacta', a multi-trunk tree up to 5 metres tall with thick green needles; 'Mini Mops' and 'Mops', dwarf varieties with short green needles; 'Pumilio', a prostrate shrub reaching up to 3 metres in height and in spread.
Ponderosa Pine (Pinus ponderosa) is a high tree with a conical crown that later becomes pyramidal. It has long (30 centimetres) dark green needles (typically three needles per fascile). Its popular varieties are 'Arizonica' with black bark, 'Deflexa', a variety with inclined bluish shoots and three needles per fascicle, 'Macrophylla' and 'Mayriana' with long needles (40 centimetres), and 'Pendula' with weeping shoots.
Pine trees with edible nuts are combined in the species called the Cedar. In our latitudes, Swiss Pine (Pinus cembra) and Siberian Pine (Pinus sibirica) are common. They have numerous ornamental varieties with varying needle colours and crown shapes.
The Secrets to Successfully Growing Pine
Pine is the most soil-undemanding tree and grows well in any, even very poor soils. However, it thrives in sandy soils. Most species like full light and good drainage and cannot tolerate polluted air.
Because these trees grow quite slowly, they are typically grown from two- to four-year-old seedlings. Until the age of five, Pines tolerate transplantation quite well.
When planting, space the trees 1 to 5 metres apart; plant the seedling about 1 metre deep, with the root collar at the soil level. Transplant the Pine with a ball of soil as naked roots die. If the soil is heavy, put a layer of sand, bricks, or expanded clay at the bottom of the planting hole. During the planting, you can add humus, and during the first two years, feed the trees with mineral fertilizers. Pine trees do not need special care; they are cold- and drought-resistant, only Macedonian Pine should be watered 2-3 times a season. Very young trees can sometimes freeze in the winter or get sunburns in early spring, so they need to be covered with spruce branches in the autumn. Remove sheltering only in mid-April.
Pine trees do not require pruning. You can prune if you want to slow down the growth or make a denser crown. There is no need to clean fallen needles as they retain moisture and make perfect mulch.
Varietal Pines are propagated by grafting; other species can be propagated by grafting and seed.
Graft young cuttings of up to 6 centimetres long without needles (leave needles only at the top) into young Scots Pine seedlings. In the spring, graft into the last year's shoot, and in the summer, no later than mid-July, into the current year's shoot.
Pine seeds germinate quite well. You might want to stratify them for 2-4 months at 3-6 ° C. The seeds are more frequently sown in the spring (the seeds of the five-needle species can be sown in the autumn) in the greenhouse or directly in open ground. Cover the seedlings with non-woven fabric and regularly remove it for watering and airing. In the autumn, cover with spruce branches or dry leaves. Transplant the two- or three-year-old trees to a new location and continue regularly watering, fertilizing, weeding, and loosening the soil. Plant the seedlings out to a permanent location when they are 5 or 6 years old. Mature plants do not need watering, weeding, or fertilizing.
Potential Problems
Sometimes Pines can be attacked by the pine adelgids (needles get lighter and white fluff appears), pine bark bugs (discolouration of needles and drying of the tops), pine mealybugs (needles twist, white-shelled insects appear on the needles), pine sawflies (it bites needles, which causes yellowish spots on the crown), and pine aphids (grey powder appears on the needles). Control pests with spraying insecticides or soapy water in spring.
It is harder to get rid of the small pine scale that causes the needle drop. In May and June, when the larvae emerge, treat the trees with Acarine.
Cones can be damaged by the cone moth and the pine weevil. Treat the trees with special insecticides.
Pines can get cancer. In the spring, the needles turn brown and fall off; in the summer, the shoots get covered with ulcers and die. To prevent the disease, treat with Fundazole throughout the season.
As with spruce, Pines can get schutte causing needle spotting and rust causing orange-brown bubbles on the needles. At the first signs of the disease, treat the trees with a Bordeaux liquid solution or colloidal sulphur in the summer and autumn.
