Pelargonium suburbanum is a sprawling, mat forming herbaceous
shrublet, with dark green leaves and large dark pink to purple flowers
from mid-winter to mid summer (June to well into January). It occurs
in the winter rainfall area of southern Africa, from the Cape Peninsula
to Port Elizabeth. This particular subspecies occurs in coastal
areas in the Eastern Cape from Humansdorp to Port Elizabeth, where
it often grows in openings in low scrub on sand dunes. This area
receives rain in summer too.
Pelargonium suburbanum subsp. suburbanum belongs
in the family Geraniaceae, a large cosmopolitan family of approximately
11 genera and 800 species in subtropical and temperate regions of
the world. The South African genera in the Geraniaceae family are
Pelargonium, Geranium, Erodium, Monsonia and Sarcocaulon.
There are approximately 270 species of Pelargonium which
occur in S, E and NE Africa, Asia, St Helena, Tristan da Cunha,
Madagascar, Australia and New Zealand, most of which ( ±
219 species) occur in southern Africa, with a large concentration
of more than 135 species that occur in the southern portion of South
Africa between Nieuwoudtville in the West and Port Elizabeth in
The distinctive shape of the seed pod of geranium plants is responsible
for the name of the both the genus Geranium and the family
Geraniaceae, from the Greek geranos, a crane, as the seed
pod resembles the head and beak of a crane. Similarly Pelargonium
is derived from the Greek pelargos, a stork, and Erodium
is from the Greek erodios, a heron, as the fruit resembles
the head and/or bill of these birds. The botanical names can thus
be translated as crane's-bill, stork's-bill and heron's-bill respectively.
The name suburbanum refers to the original name given to
this plant, Pelargonium urbanum, as the first collection
of this plant was apparently made in an urban area (urbanus
in Latin). The common name, wildemalva, means 'wild mallow' in English,
and is a name applied to many South African pelargoniums, although
not in the translated form.
species and hybrids of Pelargonium are commonly called geraniums,
a misnomer that has stuck, while true geraniums are also commonly
called geraniums, or are known as crane's-bill. This 'name-sharing'
has resulted in confusion between these two genera, but they can
in fact be very easily distinguished.
The genus Geranium has flowers with five equal petals symmetrically
arranged that can be divided into two equal halves along more than
one plane, while the genus Pelargonium has flowers which
can only be cut into two equal halves along one plane, in this case
the vertical plane. The flowers of Pelargonium suburbanum
subsp. suburbanum for instance have two large upper petals
and two or three much smaller lower petals. A photograph of Geranium
incanum, the carpet geranium, is shown for comparison between
a typical Geranium flower and a Pelargonium flower.
Plants from both genera are grown in large numbers in gardens in
both the Northern and Southern Hemisphere. Pelargoniums are one
of the most popular pot- and bedding plants in Europe and North
America and have been cultivated since 1672, when they were first
introduced to the European public. Francis Masson collected about
fifty species of Cape pelargoniums in 1772. From these and other
South African species, plant breeders have produced the ivy-leaved-,
zonal-, regal-, rose- and other types of "geraniums" with
flowers in colours from dazzling white to deep, nearly black purple.
However, many of the pure species from South Africa, although more
difficult to cultivate than the commercial varieties, are just as
varied and amazing in form and colour. Many of the South African
Pelargonium species have strongly scented foliage and some hybrids
produce oils that are used in the perfume industry.
Growing Pelargonium suburbanum subsp.
Pelargonium suburbanum subsp. suburbanum is a fast
growing, showy, long flowering plant, an outstanding plant for rockeries,
walls and steep slopes, an excellent ground cover in a sunny position
in any garden, and is tolerant of coastal conditions. It is also
suitable for hanging baskets, window boxes or tubs. It flowers from
mid-winter until mid-summer (the end of June to well into January),
with a peak during early summer (October to December).
Pelargoniums like plenty of light, a well-drained soil, and good
air circulation. Light shade or full shade for part of the day is
tolerated by most South African Pelargonium species. In their
natural environment they are found growing in the shelter of bushes
or rocks, where even if the leaves are exposed, the roots are cool.
A good sandy, loamy soil of 1 part loam : 2 parts sand : 2 parts
compost, plus some fertilizer, will suit most pelargoniums. The
soil pH is not a critical factor, and a neutral to slightly acidic
pH is suitable for most species. Watering is an important factor
in the cultivation of pelargoniums, both for their growth rate and
for the health of the plants. A general rule of thumb is to only
water when dry and under-watering is preferable to over-watering
as almost all their problems in cultivation arise from over-watering
or poor drainage. The stems of Pelargonium suburbanum subsp.
suburbanum can be slightly hairy and thus retain water on
their surface. Watering should be done in the early morning to prevent
outbreaks of fungal diseases or rust. Pelargoniums are tender to
frost and will succumb to wet cold and prolonged frost and are not
suitable for permanent outdoor cultivation in areas with a winter
minimum of less than -1 to 4 oC (30 to 40 oF) (USDA Zone 10).
The plants are not long lived and should be replanted after two
years, when they tend to start dying off from the centre. However,
they are very easy to propagate from cuttings and seed germinates
Stem cuttings may be taken in summer or autumn from a parent plant
that is strong and healthy. The stem should be fairly firm but not
woody, with at least 3 to 5 leaf nodes, and cut just below a node.
The leaves and stipules should be removed leaving only a few leaves
intact on the top. Large leaves may be trimmed to reduce moisture
loss. The cuttings should be left to dry for a few hours before
being placed in the soil. The cuttings should be rooted in trays
or in cold frames, in a well-drained medium e.g. coarse river sand.
They can also be planted directly into the ground, as long as they
are given light shade and are watered regularly until they have
rooted. The basal ends of the cutting should be dipped in a rooting
hormone to improve the rate of rooting and inserted in a prepared
hole made by a dibber or a nail to avoid damaging the ends. The
cuttings should be watered regularly but kept on the dry side, as
over-watering will result in losses. After root formation has started,
4 to 8 weeks later, the cuttings should be fed with a seaweed-based
fertilizer and potted up 1 or 2 weeks after this. Plants produced
this way will flower in approximately 3 to 6 months.
The seed of pelargoniums has an interesting mechanism: the elliptical
seeds have a feathered tail-like structure, which is coiled into
a spiral. The tail causes the seed to be twisted around so that
it drills into the soil in a corkscrew fashion and thus secures
itself in the soil. For optimum germination, seed is best sown when
fresh, although it may remain viable for up to 7 years. Sow seed
in a light, well-drained soil with a high content of coarse sand.
Firm down and level the medium gently. Broadcast the seed evenly,
covering it with a layer of clean sand. The depth of sowing is usually
one and a half times the size of the seed. Water thoroughly but
gently and provide light shade. Germination usually takes place
within 10 to 14 days but can take longer if temperatures are low.
Plants grown from seed are generally more vigorous than those produced
from cuttings, however, they take longer to flower, from 12 to 18
months after sowing, and may also display a certain amount of variation.
- van der Walt, J.J.A. & Vorster, P.J., 1988, Pelargoniums
of Southern Africa, Volume 3, National Botanic Gardens, Cape
- Powrie, F. (compiled by), Grow South African Plants,
Kirstenbosch Gardening Series, National Botanical Institute, Cape
- Lighton, Conrad., 1973, Cape Floral Kingdom
- Bailey, L.H., The Standard Cyclopedia of Horticulture
- Jackson, W.P.U., 1990, Origins and Meanings of Names of South
African Plant Genera, U.C.T. Printing Dept., Cape Town.
- Leistner, O.A. (ed.), 2000, Seed plants of southern Africa:
families and genera, Strelitzia 10., National Botanical Institute,
Authors: H.G. Jamieson and L. May.