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.
occur naturally within a radius of 50 km of the Durban
plants that I am growing are all from a very compact free flowering
form that I found growing in full sun above north
facing cliffs overlooking
River Valley at Monteseel inland of Durban. This form is a true gem of a plant it is a magnificent horticultural specimen being neat, compact and producing large amounts of clear white flowers over a long period of time. It is easy to grow has not shown any signs of being subjected to rot or any other diseases and has not been attacked by insect pests.
A very neat, small,
succulent with a large tuberous root system.
I have been growing my plants very
successfully in a growing medium consisting of expanded clay granules,
crushed brick, soil derived from sandstone, and well decomposed compost
plants are being grown for their neat growth habit and attractive
flowers that are produced in abundance
plants respond very well to irrigation they can survive extended
periods of drought.
Disease and pest resistance
To date I have not
encountered any disease or pests
Suitability as Green Roof plants
plants are valuable in plantings in shallow fertile green roof growing
mediums that are going to get the very minimum
or no water in winter as well in combinations with other plants that do
not have a
very vigorous nature. It reproduces it´s self readily from seed.
Biodiversity value in the Green
large numbers of insects in particular bees and small butterflies as
well as small beetles making it a valuable contributer to the
biodiversity in any rooftop or garden.
Cautions and precautions in the Green Roof
should be taken to ensure good drainage in particular during
establishment but this being said I have had them establish themselves
from seed in areas that I would have thought had been too wet..
They can be propagated very easily in
large numbers from seed that
germinates readily provided that one takes the care required for
growing succulents from seed. For the less experienced grower or the
grower who only wants to propagate a small number of plants they can be
grown easily from tip cuttings.
Drought responses of diurnal gas exchange, malic acid accumulation and
water status in Delosperma tradescanthioides. When well watered, this
species exhibited Crassulacean acid
metabolism (CAM)-cycling, but its carbon fixation pattern
changed during the development of drought, shifting to either low-level
CAM or to CAM idling. The rate and pattern of this change depended on
environmental conditions, duration of water stress and leaf age. At the
onset of drought, diurnal malate fluctuation increased, but was
strongly depressed (by ca 70%) as drought continued, and when leaf
water content and water potential were low (ca 35 and 50% of the
initial levels, respectively). When rewatered, rates of growth and
photosynthesis, gas exchange and water status recovered fully to
pre-stressed values within two days. Whole-shoot carbon uptake rates
suggested that leaf growth had continued unabated during a short-term (
one week) drought. This emphasizes that CAM-idling allows the
maintenance of active metabolism with negligible gas exchange when soil
water is limiting. It is possible that old or senescent leaves may
provide water for the expansion of developing leaves during initial
periods of drought. Regardless of the water regime and environmental
conditions, leaf nocturnal malate accumulation and water content were
positively correlated and increased with leaf age. Thus the gradual
loss of water from older mature leaves may induce CAM-idling, which
reduces water loss. An important ecological consequence of this
combination of CAM modes is the potential to switch rapidly between
fast growth via C3 gas exchanges when well-watered to
water-conserving CAM-idling during drought.