Portulacaria Afra, commonly known as the dwarf jade plant, elephant bush or spekboom, in Afrkaans, is a succulent plant originating in the east of South Africa and popular around the world as a houseplant and also used for bonsai. Perhaps you have some growing at home. I wanted to share with you its beauty and its potential for carbon sequestration.
This amazing, yet widely grown plant, has been found to be important in its capacity to capture carbon and restore natural ecosystems. It is able to store moisture in both its leaves and stem and can capture as much as 4.2 tons of carbon per hectare annually, making it a very significant plant.
In fact, Portulacaria Afra can switch between C3 and CAM photosynthetic pathways. When moisture is plentiful the plant uses the usual efficient C3 pathways. During dry periods and drought conditions it switches to night-time CO2 fixation through CAM pathways. Therefore Portulacaria Afra can have high carbon-fixation rates even under semi arid conditions which would usually make photsynthesis and carbon fixation more difficult. Importantly then, this plant can adapt to the variable conditions in which it is growing and still influence soil carbon stocks. Scientists see great potential in this ability to adapt.
In South Africa, Portulacaria Afra thrives in areas of heat and drought and shares a symbiotic relationship with elephants and other grazing animals that help it to spread vegetatitively into thickets by way of the cast off pieces that the animals leave behind. Here is a link to a site that shows elephants devouring the portulacaria growing wild at Addo in South Africa as well as giving other interesting information about the plant.
Here in Sydney we have some large, mature specimens growing in our garden and when we cut back a plant and hardened off some of the cuttings it seemed we provided enough stress for the cuttings to flower. Apparently, Portulacaria Afra will only flower after good summer rains, so maybe it was a combination of neglect and the recent rain.
However, having never seen the plant in flower in Sydney before, (even after 30 years of growth,) I thought I would share these images with you. The flowers are tiny on my cuttings, but I have enlarged them about 50x to show you the beauty of the pink blossoms. In the east of South Africa, where they originate, they more commonly flower. My humble little flowers don’t do justice to the plant in its own habitat.
I have done some reading and found that by watering using a sprinkler over the plants in the heat of summer and after a long dry spell, the plants my flower. I will be trying this and post an update if I am successful.
After doing my research, I have a whole new respect for this humble plant. I will be keeping my large, old specimens rather than cutting them down as I had considered doing and so do my little bit for carbon capture for the planet.
Additionally, this is an easy plant to grow in the home garden. It can be pruned and easily propagated and can be trimmed into hedges and borders as one of my canny neighbours did a few years ago, or just grown in large pots. Being so drought resistant it is a great water saving plant.
So, do consider giving the hardy Portulacaria Afra a place in your home garden and play your part, no matter how small, in removing carbon from the atmosphere.