This lovely, delicate plant is a jewel in the garden for it flowers
abundantly throughout the summer. In the wild it is found throughout
the mountainous areas of the northeastern and eastern Free State,
Lesotho, the northeastern Cape and the southern KwaZulu-Natal Drakensberg.
ground the thin stems may look soft and the pink flowers dainty,
but they root firmly into rock crevices and gritty soil on the slopes.
Finding diascias on these high mountains flowering with geraniums,
kniphofias, suteras and dieramas is a magnificent sight.
Diascia integerrima is one of the most widespread, toughest
and floriferous of the all the Diascia species. It grows
in clumps branching from the ground into many wiry, but rigid stems.
Sometimes the square stems can get a bit woody at the base, but
they are usually soft and blue-green. The stems are 30-40 cm tall,
but grow longer if they have to climb through surrounding bushes.
The narrow leaves are mostly at the bottom of the stems, with a
few smaller ones towards the top where the fat flower buds hang
like little bells. While the bottom flowers open, new buds are continually
forming at the tip of the stems and flowers are produced throughout
the summer. Close-up these bright pink flowers are very interesting.Typical
of Diascia, the flowers have two long horns or spurs at the
back of the flower, which has given this genus the common name of
twinspurs. The flower is shaped with a large drooping lower lip
and four smaller curly petals at the top. At the centre of the flower
there is a bright yellow and maroon concave patch called a "window".
The pollination of diascias by special oil collecting bees in the
wild, is fascinating. These specialized bees have modified forelegs
with which they collect oil from inside the two spurs. Once cross-pollinated,
little round seeds are formed in capsules. Within a few weeks the
seed capsules turn brown and dry, split open and release the ripe
seeds that are black and hard.
The genus Diascia contains about 70 species, and is found
only in southern Africa. The summer rainfall area of the KwaZulu-Natal
Drakensberg is rich in perennial species like Diascia integerrima
while about 50, mostly annual species are found in the winter rainfall
area of the Western Cape and Namaqualand. The genus name Diascia
is derived from Greek meaning di = two and askos =
sac, referring to the two oil containing spurs.
Growing Diascia integerrima
At Kirstenbosch, Diascia integerrima has been a firm favourite
for summer colour for many years. A delightful evergreen perennial,
it is used in pots, rockeries, hanging baskets, to fill little pockets
between other plants and in large sweeps in the garden beds. The
possibilities for mixing Diascia intergerrima with other
summer flowers are endless, whether it is with other perennials
like blue Wahlenbergia
undulata or mauve Monopsis
unidentata; or for a spectacular sight with bulbs like the
tall graceful bells of Dierama pendulina or the blue spikes
of Scilla natalensis.
The bright pink flowers also make a wonderful contrast with the
grey foliage of Cotyledon orbiculata (plakkie) or Stoebe
plumosa (slangbos). A large pot filled only with a mass of flowering
Diascia intergerrima, is also an unforgettable sight.
Diascia integerrima requires a sunny position and well-drained,
good garden soil prepared with plenty of compost. Although Diascia
integerrima is more tolerant of dry conditions than most twinspurs,
it still requires regular watering throughout the year. By the end
of summer the plants usually look untidy and they go slightly dormant
during winter. Diascia integerrima is quite hardy and will
survive low temperatures and heavy frost. If established plants
are cut back they will shoot out afresh the next summer, but for
the best display they should be propagated and replanted every year.
A white flowering form of Diascia integerrima is also available,but
unfortunately it is not as tough as the pink.
The easiest way to propagate Diascia integerrima is by cuttings.
Select non-flowering growth 5 to 6 cm long, semi-ripe, softwood
or young shoots from the base. The best time to propagate is when
the plants shoot in spring or cuttings can be taken throughout the
summer and autumn. At Kirstenbosch the cuttings are treated with
a rooting hormone, placed in a tray filled with a mix of bark and
polystyrene and watered with a fungicide. The tray is placed in
a mist unit with bottom heat. The cuttings root easily within 10
Diascia species are self-incompatible and, therefore, do
not set seed easily in the garden.
Liesl van der Walt