Hormones in Trees

Common Trees used in bonsai and used by Mikibu Bonsai.

v      Thorn Trees (acacia galpinii and acacia burkei). Small hooked Thorns. Frost tolerant, semi-deciduous. They create a small bonsai very quickly as the leaves are naturally small and the bark flakey. Avoid the acacias with large thorns as the thorn looks out of proportion with the rest of the tree. The Black Monkey Thorn (acacia burkei) adjusts well indoors.

v  Baobab (adansonia digitata). An extremely difficult tree to maintain if you live outside its natural distribution area or you are new to bonsai. The Baobab makeup is close to a succulent as far as watering is concerned. When leafless NO water to little water may be applied. Over watering may cause root and trunk rot. The Baobab is sensitive to cold temperatures and once over 10 years old becomes more tolerant to colder temperatures below 10 deg C. The Baobab has its own unique African style. It grows extremely slowly in a pot and starting off with seedlings may prove to be frustrating. If you want one try buying a large one and cut it down. Growing it from seed is frustrating. [Go to TOP]

v      Coral Tree (erythrina lysistemon) Growth is very fast in summer. The tree is cold sensitive and does not tolerated frost. Leaf reduction is difficult and is achieved best with limited watering. It is cold sensitive to about 4 deg C. Being indigenous it is prone to bugs and a worm that eat out the inside of the trunk, eventually killing it. Rammification is very difficult as the leaves sprout everywhere. To reduce the leaf size, cut off the apical leaf and leave the other two.[Go to TOP]

v      White Stinkwood (celtis africana). A deciduous fast growing indigenous tree. Hardy to intense heat and extreme cold. Drought resistant but certainly likes water. Clip and grow gives the best results in short periods of time. Leaf reduction is easily achieved and rewarding. Aerial roots are common and should be removed. This tree is a good tree for a novice. Repot every year to 2 years. Often confused with other celtis family (celtis chinensis and celtis australis which have a smoother rounder leaf.) Rammification and fine branching is achieved easily. [Go to TOP]

v      Red Ivory (berchemia zeyerhi). A semi deciduous tree. The wood is hard and heavy. The leaves are bluish to red with noticeable veins. Very slow grower. Leaves reduce considerably. Reports of dieback on a whole branch. [Go to TOP]

v     Wild Figs (ficus). Evergreen. Sensitive to cold under 5 deg C, yet some of the imported ficus microcarpa tolerate freezing conditions.. Very suitable for root over rock style. Can be grown indoors in high light areas. Recognised by the white milky sap flowing from a wound. A good tree for a novice. A fast grower with good rammification and leaves miniaturize easily. Loves to be fed.[Go to TOP]

v     Wild Olive (olea europaea sub africana). Evergreen, hardy to frost and drought. Leaf reduction by regular leaf removal. Enjoys full sun. Handles frost and drought. Extremely slow growing. The tree is known to live beyond 2’000 years old. The wood is extremely hard and old wood is difficult to cut, carve and wire. The soil pH should be neutral to alkaline. The olive is susceptible to attack by insects. The olive forms a beautiful crown. Do not keep indoors for longer than 30 days. A stressed tree can take 3 years to regenerate. A good tree for a novice bonsaiist. [Go to TOP]

v      Tamboti (spirostachys africana). A deciduous tree. The wood is hard. Leaves reduction is easily achieved. The sap is poisonous. Leaves reduce nicely. Tolerated cold but grows best in warm areas. [Go to TOP]

v     Black Pine (pinus thunbergii). Evergreen. Needle must be pinched and not cut. Needle reduction is difficult, and is reduced with regular candle removal. In Gauteng it is always being attacked by a white fungus, which eventually kills the tree. The summers tend to be too hot. [Go to TOP]

v     Swamp Cypress (taxodium distichum). Deciduous formal upright tree with soft feather type leaves. The roots can live in water and prefer a clay and muddy potting mix. Grows very fast. The tree forms a good taper and should be higher than 30cm. It lends itself to the formal upright style.  It is a good bonsai subject for a novice. [Go to TOP]

v     Hinoki Cypress (chamaecyparis obtuse). Small evergreen. Typically grows as a lollipop. Extremely slow growing making them very rare and sought after. Old growth must be plucked from the crown in order to allow light into the branches and stop insects, otherwise the branch dies. Foliage is rosette shaped. All cypress do not like tropical climates. [Go to TOP]

v     Junipers. (Juniperus).

1.      General. Evergreen. The most popular is the creeper Procumbens nana followed by Juniperus chinensis.

2.      Watering. All year round, with less in winter, although drought tolerant.

3.      Placement. Outdoors. Frost and Cold resistant. They are light hungry and can be grown in full sun, but full shade produces greener results.

4.      Feeding. All year round.

5.      Repotting. Every 2 to 5 yrs in spring.

6.      Pruning. All year but groth will stop in the cold season.

7.      Styling. Stunning trees are created through clip and grow and wiring. They lend themselves to gnarled and twisted  trunks, tuniki or driftwood styles, with exposed gins and sharis. The branches take one to 2 years to set after wiring due to the springy nature of the branches, which often results in wire damage.

8.      Pinching. As the buds are soft, select 3 buds and pinch out the middle. This encourages a fuller foliage.

Caution. Wiring and repotting at the same time leads to a lot of death through stress. So separate these two activities. In nature they naturally shred branches. Very common in the cascade styles. A good starter tree.

If you are having problems with any conifer species not growing well with loss of colour and vigour, try using a teaspoon of white wine vinegar to 1 litre and water the soil with the solution. This adds acidity to the soil. The needles will turn bright green and the tree will look happier. [Go to TOP]

v     Maples - (acer family).

1.      General. A deciduous tree, mainly known for it bright red brilliant foliage in Autumn. The most popular is the Trident or Chinese maple (acer buergerianum), as it grows fast. A good starter tree.

2.      Watering. Ample water all year round, with less in winter, They do not like dry conditions.

3.      Placement. Outdoors. Frost and Cold resistant. Avoid placing them in full sun, as invariably the roots dry out causing marginal leaf burn. Avoid the harsh afternoon sun.

4.      Feeding. Spring and summer, balanced food.

5.      Repotting. Every 1 to 3 yrs. For those who are wanting to transplant the different types of Maple should do it while it is dormant, in July/ August.  Remember to take note of any trees that still have wire on to see that it does not cause wire damage.

6.      Pruning. 60 % of the root ball can be pruned pre-spring. The branches ideally in winter when the tree is dormant and leafless and the ramification can be achieved.

7.      Styling. Formal upright, informal upright, root over rock.

8.      Pinching. Pinch out new shoots after two complete leaves have formed or as necessary. This encourages a fuller foliage.

9.      Caution. Many of the rare maples are grafted and have grafting scars from nurseries. [Go to TOP]

v     Liquidambar (liquidambar styraciflua). A deciduous tree with similar leaves to the maples. As they are quick growing results are obtained in a short time. Leaf reduction is good, but a larger leaf remains, so larger trees give better bonsai proportions.[Go to TOP]

v     Chinese Elm (ulmus). Deciduous tree. Leaf reduction is very good. They are frost hardy and love water. Rammification is achieved quickly. Remove wiring before winter as wired branches tend to die. A good bonsai novice tree. [Go to TOP]

v     Oak (quercus robur). Deciduous tree. Leaf reduction is non existent. The bonsai needs to be at least 50cm tall. [Go to TOP]

v     Azaleas (rhododendron). The best subject is the Kurume. The trees are renown for their different coloured flowers. Styling is done by clip and grow. It has a vigorous root system and yearly repotting is required. Azaleas can be very fussy about their growing conditions. They must have an acid soil with a PH of 5.0 to 6.5. and usually they do not tolerate lime so be aware of cement based pots. They do not like clay soils. If the soil is alkaline at all, your Azalea will be unable to access the necessary nutrients and elements vital for their health. You should try and introduce some peat moss and other organic matter to the soil. Be sure to feed regularly with an acid type Rhododendron fertilizer. When planting or repotting your Azalea plant they should be placed so that their roorball is slightly higher than the surrounding soil. Azaleas resent drying out and should be given a few hours of morning sun and partial shade during the hottest part of the day. The buds for next season’s blooms will be formed this season, so it is important that the faded blooms are removed otherwise you might not get a flower on that stem next season. Pruning consists of mainly of removing spent flowers and cutting back longer branches which may spoil the symmetry of the plant. [Go to TOP]

v     FireThorn (pyracantha). Semi deciduous. Heat resistant cold resistant and drought resistant. They are known for their bright berries. The firethorn does not like its roots cut and it is recommended that soil changes is achieved by removing a wedge of soil at a time. A good starter tree for a novice. [Go to TOP]

v     Cotoneaster. A semi deciduous shrub, with white flowers and scarlet red berries. Drought resistant and enjoys cooler weather and shade. Can be shaped through clip and grow and wiring. A good bonsai starter. Transplant in spring between its fist buds and before fruiting. [Go to TOP]

v     California Privet (ligustrum ovalifolium). Evergreen hardy tree. The leaves are naturally reduced. Good bonsai starter. The need to be fed, otherwise they loose their dense foliage. Repot every 1-2 years[Go to TOP]

v     June Snow (Serissa foetida). Small evergreen shrub. Tiny white or pink rose shaped flowers continuously appearing. Best styled through clip and grow. It will remain a small tree. Best style is informal upright or broom style. The variegated Serissa japonica does not flower as profusely as the foetida. [Go to TOP]

v     Kei-apple (Dovyalis caffra). Cold Hardy, semi-deciduous. It grows remarkable well indoors. [Go to TOP]

v     Buddleja. (Buddleja saligna). Lends itself to drift wood styles as scars do not heal. It feeds via a vein or artery system, so cutting this vein will cause branches to die. Very often a branch dies for no reason.[Go to TOP]