Combating desertification by planting the drought-tolerant spekboom (Portulacaria afra).


Photo credit: WVC Portulacaria – P1110523.JPG

A young Spekboom or Elephant Bush (Portulacaria afra) grown from a small cutting.  This succulent, drought-tolerant, edible plant is one of the most valuable species to combat desertification.  It should be used at the largest scale, e.g. in the Great Green Wall project in Africa.


Spekboom multiplication for combating desertification

Prof. Dr. Willem Van Cotthem
University of Ghent (Belgium)
One of the most interesting plant species used to combat desertification, limiting soil erosion, producing a dense vegetation cover and a remarkable number of little leaves (fodder, but also edible for humans), is the Spekboom or Elephant Bush (Portulacaria afra).
My friend Johan VAN DE VEN  was sokind to offer me some rooted cuttings. These were growing very well in pots and plastic bottles in my garden in Belgium.  In order to study different ways of multiplication of this Spekboom (with succulent branches and leaves), I started taking off small lateral shoots (cuttings) and planted them in some moistened potting soil in a transparent cake box. I also planted some of the succulent leaves (see my photos below).
Within the plastic cake box humidity is kept high (condensation of droplets on the cover). Therefore, I opened the cover from time to time to let some fresh air (oxygen) in.  Quite soon both the cuttings and leaves started rooting. The cuttings swiftly developed some new leaves. A month later, I transplanted them into small plastic bottles, twice perforated 2-3 cm (1 inch) above the bottom (for drainage, keeping a small quantity of water at the bottom for gradual moistening the bottle’s content and the rootball).
Once fully rooted within the plastic bottle, I cut off the bottom of the bottle to set the lower part of the rootball free. Then I plant the younSpekboom in a plant pit without taking off the plastic bottle, sitting as a plastic cylinder around the rootball.
The plastic cylinder will keep the rootball moistened (almost no evaporation) and it offers a possibility to water the sapling from time to time, whenever needed. Irrigation water will run through the plastic cylinder towards the bottom of the rootball growing freely in the soil (irrigation water directed towards the roots growing into the soil at the bottom of the plant pit). 
Thus a high survival rate is guaranteed.  After a couple of weeks, the rooted leaves started to form a stem bud from which a new plantlet grows.
It is clear that multiplication of the Spekboom with rooting cuttings and leaves is very easy. This is another interesting aspect of this remarkable plant species. I can only recommend a broader use of the Spekboom for reforestation, fodder production and even production of bonsais for enhancement of the annual income (export to developed countries).
Here are some photos of this experiment:
2010-04-06 : A Spekboom cutting planted in potting soil in a plastic soda bottle is rooting very quickly in my garden in Belgium. (Photo WVC Spekboom P1030792.JPG )
-2010-04-06 : Massive root development in the bottle, with 2 opposite drainage holes 2-3 cm (1 inch) above the bottom to save irrigation water (Photo WVC Spekboom P1030794.JPG )
2010-04-06 : Cuttings are rooting very splendidly (Photo WVC Spekboom P1030807.JPG)
2010-04-06 : Lateral shoots with succulent leaves (Photo WVC Spekboom P1030808.JPG)
2010-04-06 : Small cuttings (lateral shoots) and some leaves planted in potting soil in a plastic pastry box. (Photo WVC Spekboom P1030802.JPG)
2010-04-06 : The small cuttings are growing quickly into young plantlets (Photo WVC Spekboom P1030806.JPG)


2010-05-23 : Rooted leaves, an easy way to produce a huge number of plantlets of the Spekboom starting with one single cutting. What an advantage for reforestation and combating desertification ! (Photo WVC Spekboom P1030992 copy.JPG)
2010-05-23 : Rooted small cutting (lateral shoot), ready to be transplanted (Photo WVC Spekboom P1030994.JPG)
2010-05-23 : Rooted cutting transplanted into potting soil in a plastic Ice tea bottle, perforated at 2-3 cm above the bottom (drainage). (Photo WVC Spekboom P1030995.JPG )
2011-10-15 : One year later the small cuttings has grown into a young plant that can be transplanted into the field. (Photo WVC Spekboom P1070779.JPG)
2011-10-15 : The plastic bottle contains a very healthy rootball (Photo WVC Spekboom P1070781.JPG)


We are planting saplings with the bottle in which they were growing, so that their root ball is nor disturbed and kept fully moistened. Therefore, we cut the bottom part of the bottle to set the rootball free.  Once the saplings is developing its roots in the soil, we can pull the plastic cylinder out of the plantpit.  This planting technique offers a maximum of survival rate. (Photo WVC Chlorophytum P1090167.JPG)

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Willem Van Cotthem

Honorary Professor of Botany, University of Ghent (Belgium). Scientific Consultant for Desertification and Sustainable Development.