Basically, there are three main varieties of trees that are appropriate for cultivation as bonsai – namely coniferous trees, deciduous trees and ornamental shrubs. A brief discussion on each of these varieties is presented below.
Coniferous trees have been named so because of their cones or distinctive fruits. Nearly all conifers are evergreen trees and this helps them to maintain a steady form, notwithstanding the season. However, when we say that conifers are mostly evergreens, we do not mean that they never shed their “leaves”, which are generally needles. However, these leaves or needles are continually and instantly substituted by new growths. This is the main reason why conifers always remain evergreen.
Conifers are excellent for growing as bonsai trees. They adapt themselves to bonsai treatment easily. Most importantly, pines readily accept the pruning of their branches. In addition, you can easily wire their branches and trunks to give them an arching form. Pines can also develop into stunning specimens in a very brief period – only a few years.
Usually, conifers are very resilient trees and, hence, they need minimum after care. This is one reason why conifers are excellent trees for a novice bonsai grower. In several instances, the only thing that growers need to do is just pinch out the shoots and buds in spring and remove the dead needles during autumn. Conifers have a performance for sunlit positions. However, you need to ensure that the root ball of the tree does not become dehydrated. It is worth mentioning here that since majority of conifers have their origin in the relatively arid regions of the world, you do not require watering them often or much.
Here is one thing that you should never forget. Scrape the bark of older conifer trees. This is important because such trees usually harbour various types of parasites. One parasite that is commonly found on the bark of most old conifers is the egg of over wintering greenfly.
- Silver fir ( Abies alba )
- This conifer grows short and has prickly evergreen needles, while its cones are upright.
- Cedar ( Cedrus spp. )
- Similar to silver fir, the evergreen needles of cedar are also short and prickly and have a dark green hue.
- False cypress ( Chamaecyparis spp. )
- The habit of this evergreen species varies and it develops very slowly.
- Japanese cedar ( Cryptomeria japonica )
- This is also a slow growing evergreen conifer whose green foliages changes to reddish-bronze during autumn.
- Chinese juniper ( Juniperus chinensis )
- This is a leafy evergreen species whose leaves have a sea green hue.
- Needle juniper ( Juniperus rigida var. nipponica )
- Juniper trees produce slender, sharply pointed needles that are evergreen. The cones or fruits of this species may appear in green, blue or reddish hues.
- Larch ( Larix spp. )
- The needles produced by trees belonging to this species are deciduous in nature. The needles are light green during spring, but change to a darker hue in summer. Their color changes again to gold in autumn.
- Spruce ( Picea spp. )
- This species produces upright evergreen needles, while its cones are suspended.
- Japanese white pine ( Pinus thunbergii )
- The needles of this tree are small, delicate and have a bluish green hue.
- Japanese black pine ( Pinus parviflora )
- Unlike the Japanese white pine, the needles of this species are strong, vigorous and have a deep greyish-green hue.
- Yew ( Taxus baccata )
- The evergreen needles of yew are blunt and have a dark green color. The berries, known as arils, have a vibrant scarlet hue.
Like the trees found in temperate forests, deciduous trees are also very familiar. These trees shed their leaves in autumn after an active growing season, which begins with the onset of spring or in mid-spring, subject to the species.
It has been proved that nearly all types of deciduous trees can be developed as bonsai. However, some are more suitable than the others. The most suitable deciduous trees include beeches, elms, horn beams and maples. These deciduous trees readily accept pruning of their leaves and shoots. In addition, most of these deciduous trees have their origin in the Far East and by nature they have an additional advantage – their leaves are very small. All deciduous trees change their color during autumn, creating a magnificent effect. Their color changes from different shades of green to anything ranging between gold and scarlet. This is considered to be an additional bonus of growing deciduous trees as bonsais and, to some extent, this compensates for their nakedness during the winter months.
When deciduous trees become habituated to the temperate climatic conditions, it becomes easier to grow them, depending on whether or not you are watering them properly and keeping the trees sheltered from the sun’s heat. When a tree shows robust growth, it becomes necessary to keep its shoots within limits. This can be achieved by undertaking repeated pinching out of the buds and shoots to make sure that the tree has a bare minimum of leaves necessary for its survival as well as aesthetic beauty. Undertaking skilful pruning of the shoots during when the trees are in their dormant stage will help to give them your desired shape.
Precisely speaking, deciduous trees are ideal for use in a variety of group arrangements – they can be arranged in trays or even on any large stone slab. They are perfect for a quiet as well as graceful way of exhibiting bonsai trees.
- Trident maple ( Acer buergeranum )
- This deciduous species produces green leaves with jagged margins. These leaves change their color to bright orange during autumn.
- Japanese maple ( Acer palmatum )
- The leaves of Japanese maple have minute dentate or toothed margins along with five to seven lobes. Like the leaves of trident maple, the leaves of this deciduous species also change to bright orange or red during autumn.
- Black birch ( Betula nigra )
- The foliage of this deciduous species has a pale green color, while the trunk is reddish brown having a white base. The bark of black birch flakes off as sheets.
- Hornbeam ( Carpinus laxiflora )
- This deciduous species produces copious foliage during spring.
- Beech ( Fagus crenata )
- The leaves of beech have notched margins forming rounded teeth (crenate) and their color changes to brown during autumn. However, the leaves of this species fall only in spring.
- Maidenhair tree ( Ginkgo biloba )
- The leaves of this tree are divided into two lobes shaped like a fan. The color of the leaves is green during summer, but change to yellow during autumn.
- Nagasaki crab apple ( Malus cerasifera )
- In spring, this tree is covered with flowers and if they are pollinated, small apples appear soon. The leaves of this deciduous species are rather large.
- Chinese elm ( Ulmus parvifolia )
- The tiny leaves of Chinese elm are shiny, while the bark is cracked and flaking.
- Grey bark elm ( Zelkova serrata )
- Trees of this deciduous species produce tiny, oval shaped leaves. The branches are spreading, while the foliage is copious.
All shrubs are ornamental trees, thanks to their beautiful leaves, blooms or fruits. Their decorative value makes them dear to many bonsai growers. Species belonging to the ornamental shrub group may be significantly different. This is because the only attribute that is necessary for them or that should be common to all the species is their decorative look. Therefore, we need to distinguish between shrubs that flower during spring, summer and winter; shrubs bearing fruits like those produced by any normal fruiting tree like the apple; and the shrubs that produce vividly hued, merely showy berries.
Even the growing techniques involved in developing these ornamental shrubs may be significantly different. This is also true for the pruning methods adopted to keep them in precise shape. Generally speaking, shrubs that flower early in the season – for instance, some shrubs produce flowers before the appearance of the leaves need to be pruned immediately when their flowers start wilting. On the other hand, shrubs blooming later in the season (either toward the end of spring or in summer) need to be pruned during the winter months. They can also be pruned prior to the commencement of new growths in spring. When a bonsai tree bears flowers and/ or fruits, it looks magnificent – mainly owing to the abundance of small flowers and fruits, as well as their diminutive size. However, the flowers and fruits of such trees are not as noticeable as their leaves.
Nearly all types of ornamental bonsai shrubs are of the outdoor variety. However, it is essential to protect the ornamental shrubs that have their origin in the Mediterranean region from frosts during the winter months.
- Japanese camellia ( Camellia japonica )
- The leaves of this ornamental shrub are evergreen. Japanese camellia is in bloom during the period between mid-winter and spring.
- Rock cotoneaster ( Cotoneaster horizontalis )
- This shrub produces tiny, glossy, green hued leaves that change to red in autumn. It is an upright shrub bearing red berries.
- Hawthorn ( Crataegus spp. )
- This is a thorny shrub producing small leaves having jagged margins. The color of hawthorn flowers may vary from white, pink or red. The plant bears ornamental fruits in summer.
- Winter jasmine ( Jasminum nudiflorum )
- This ornamental shrub has green squarish branches with a cascading habit. The plant produces a profusion of yellow flowers during the winter months.
- Crab apple ( Malus spp. )
- This is an ornamental shrub that produces glossy, oval shaped leaves. The color of the flowers of this shrub varies from white to deep pink. It produces red fruits similar to the size of cherry.
- Japanese apricot ( Prunus mume )
- The leaves of Japanese apricot are small, oval shaped, while flowers are bright pink. The shrub is in bloom during the winter months. This plant has a slender growth.
- Almond ( Prunus amygdalus )
- Almond shrubs are ornamental and produce pointed and, somewhat dentate leaves. The white flowers of this shrub bloom in winter.
- Japanese cherry ( Prunus serrulata )
- This is another ornamental shrub that produces oval shaped leaves. The shrub is in bloom during the period between mid-spring and late spring. The color of the flowers varies from white to pink.
- Firethorn ( Pyracantha angustifolia )
- As the name of the shrub suggests, it produces thorny, evergreen leaves with pointed ends. This shrub blooms during summer and its color of its flowers varies from yellow, orange or red. The fruits of firethorn come in autumn.
- Rhododendron spp.
- The evergreen leaves of this shrub are glossy and pointed. Shrubs of this species produce copious flowers toward the end of spring.
- Wisteria spp.
- This shrub produces light mauve hued blooms that dangle in clusters during the latter part of spring.