Is one of a number of plant species which are presently being tested
for their suitability to be grown as Green Roof plants in the Durban
region that have initially shown good results. They all occur naturally
within a radius of 50 km of the Durban city centre
arborescens occur naturally mostly in full
sun on many rocky outcrops in the
area where they grow in very shallow soils mostly with little or no
from other plants.
These plants are medium
to large growing evergreen clump forming plants that primarily
reproduce by means of seed.
These plants are
extremely decorative feature plants having grey green leaves and a neat
growth habit, they produce masses of very attractive orange flowers
during the winter months. In winter the and when they are moisture
stressed the leaves in particular the leaf margins turn a distinct pink
In their natural habitat
they are able to withstand very long periods of drought due to their
succulent nature. From my experience of growing these plants as pot
plants I have found them to be very drought resistant.
Disease and pest resistance
These plants are
generally disease resistant, although they are sometimes attacked by
scale and ants can create a problem by introducing mealy bug to the
Suitability as Green Roof plants
From my experience with
these plants and from indications of plants that are being tested under
Green Roof conditions these plants certainly give the impression that
they are going to be first rate Green Roof feature plants where larger
plants are able to be grown.
Biodiversity value in the Green Roof landscape
They create robust
habitat and protection for other green roof dwellers. Their flowers
attract pollinating insects in particular honey bees and Sunbirds.
Cautions and precautions in the Green Roof
They have very vigorous
root systems so good root protection must be provided to protect the
water proof membrane. Under certain circumstance they may need to be
pruned from time to time.