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| Common Name: |
Dwarf Jade |
| Scientific Name: |
Portulacaria afra |
| Hardiness Zone: |
Zone 10A through 11 - Temperature: Portulacaria will tolerate a variety of growing conditions. Since it is tropical it must be protected from cold temperatures (below 50). |
| Family: |
Portulacaceae |
General Information
Common names include: Elephant's Food, Elephant Bush, Elephant Grass, Elephant-Plant, Olifantskos; Purslane Tree; Dwarf or Tiny Leaf Jade. The common names derive from the succulent nature of the plant's leaves and stout trunk, and also from the observation that elephants will browse upon this. It is said that in a feeding frenzy, the pachyderms will strip off all the leaves (and smaller branches) from this plant; but within a few weeks, the branches and trunks have begun to be covered again with a mantle of green. In fact, it forms 80% of the elephants' diet in the Addo National Park. Each pachyderm consumes an average of 200 kg of food per day, but the plant is not "destroyed" as a result of this symbiotic relationship. In feeding, the elephant breaks off the branches, eats the succulent leaves and then discards the larger branches, which reroot themselves. This is a stout juicy-stemmed, soft-wooded, semi-evergreen upright shrub or small tree, usually 2.5 to 4.5 or more meters tall. The diameter of the trunk can be 20 cm or more. The life expectancy of the plant, while demonstrated to be over 50 years, is unknown.
Basic Care
| Bark Characteristics: |
The greyish or reddish outer layer of the bark becomes very wrinkled with age, perpendicular to the trunk's axis. Observed in a container plant setting, the near-paper-thin outer bark can be completely removed in a ring from around the mature tree without harm. On older specimens the bark can partially dry out and flake off by itself. At least one equally thin layer would have already formed underneath. |
| Leaf/Foliage Characteristics: |
The leaves have opposite, obovate (egg-shaped), glabrous, very fleshy, blunt green leaves usually less than 1.3 cm long and without a distinct petiole or leaf stem. Less common are some old leaves which can reach at least 2.8 cm in length, up to 2.3 cm in width, and can be rounded, tear-drop, or triangular in shape. These largest leaves sometimes show a rudimentary petiole 2.5 mm wide at the branch juncture and up to 2 mm long into the leaf. If there is a petiole present, it curves slightly towards the bottomside of the leaf. New leaves arise approximately 90 degrees to the previous pair and are lighter green in color. A very limited number of previous pair leaves have been seen to be extremely stunted, barely developed, while their successors usually fully develop without any signs of retardation in these younger pads or their successors. The average life expectancy of the leaves is at least one year. The middle of the outer edge of young leaves shows a tiny pointed apex. Sometimes there is a thin faint reddish edge on younger leaves. A faint and sometimes unnoticeable cleft runs down the center of the leaf from the base to the outer tip. This feature occasionally results in heart-shaped leaves having the center of the apex drawn in. Once a green leaf has this shape it will not revert to obovate, and vice versa. |
| Growth Characteristics |
Older branches, gray, shiny and up to 5 cm thick, will hang down or trail on the ground. Spreading outward, less frequently they will grow erect, especially at the center of the plant. There is some evidence that erect branches -- to at least one meter in length and often with secondary branches extending outward at a 45 degree angle from the main branch -- thicken more quickly than trailing branches do even when the latter are feeding a greater number of secondary branches. On a limited number of upright growing branches it has been observed that the leaf pairs are rotated slightly more than 90 degrees from the one directly under them. A gentle counterclockwise spiral is formed so that, within an upward length of about 30 cm, the leaf pairs are 90 degrees to the right of the corresponding alternating pair five levels below. |
| Flower/Fruit Characteristics: |
The flowers are pink/rose/lilac-colored, 2 to 2.5 mm long and short-pedicelled. They are clustered in the upper leaf axil, the point at which the stalk or branch diverge from the stem or axis to which it is attached. "The flower is panicled, that is, with a loose, open flower cluster, approximately 5 to 7.5 cm in length, which blooms from the center or bottom toward plant is never terminated by a flower. The bisexual flower has two conspicuous persistent sepals which are papery but become stiff, five persistent petals, four to seven stamens, a four or five lobed short corolla tube, and a three-angled superior one-chambered ovary, angles winged and deeply tinged with red, with three stigmas, sessile, spreading, densely muricate above, white". |
| Lighting: |
Full sun. |
| Watering: |
Allow Jade to approach dryness before watering. Even though it is a succulent, Jade's are not as particular as other succulents when it comes to water. Overwatering will cause leafdrop. In severe cases of overwatering, the trunk may break apart at the soil line. |
| Feeding: |
Well balanced fertilizer during growing season. |
| Pruning/Wiring: |
This is a plant that adapts to almost any style bonsai. As a succulent, water is contained in the trunk and branches, they tend to droop from their weight. This characteristic makes them excellent for long cascades. When styling this plant do not hesitate to do drastic pruning. When removing branches or twigs, make all cuts flush rather than concave. Deep cuts will leave unwanted scars and may cause die back. It is not necessary to seal any of the cuts. It is important to allow the soil to dry before you remove heavy branches or root. Then water sparingly until it begins to reestablish itself. Refinement is performed by removing the terminal bud from any branch that you don't wish to grow longer. Since the leaves are opposite and each consecutive set of leaves rotate 90 degrees, it is possible to refine the tree by pinching and removing those buds and branches that are not growing where you want them. When creating very small bonsai (mame) you sometimes need to shorten a branch to a vertical set of leaves. In order to get horizontal growth it is necessary to rotate the vertical pair of leaves 90 degrees. A few turns of 1 mm aluminum wire at the top of the branch and a 90 degree twist of the last set of leaves will accomplish this. Pinching is the secret to the refinement of any bonsai. Since Portulacaria is fast growing, it must be pinched frequently during the growing season. Usually once a week is sufficient for a large bonsai. When working with mame it may be necessary to pinch as often as twice a week. While some training can be accomplished by wiring, it is not as effective a training technique with Portulacaria as it is with hard wood species of plant material. |
| Propagation: |
Cuttings work well. Let cuttings dry for a few days before potting in a sandy mixture. |
| Potting: |
Repot when nighttime tempertures are above 60 F. Repotting can be done every other year. Allow soil to dry out prior to repotting, roots and tree top can be cut back hard. After repotting, put tree in a shady spot, hold off watering for a few days until new growth starts to sprout, then water. |
| Pests: |
Mealy bugs, aphids. |
| Diseases: |
Root rot, indicated by yellowing leaves. |
| Bibliography: |
A detailed monograph on Portulacaria afra may be seen at: http://www.phoenixbonsai.com/Portulacaria.html Dwarf Jade - Portulacaria afra, www.bonsai-bci.com |
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