Acacia karoo

Click on an image to enlarge it.

Botanical Name

Acacia karoo

Family

Fabaceae - The legume and pod-bearing family. (Pea & Bean Family)

Pronunciation

uh-KAY-shuh kuh-ROO

Common Name(s)

Sweet Thorn; Soetdoring

Plant Group

Tree A woody, self-supporting perennial plant usually with a single main stem and generally growing more than 6 meters tall.

Plant Size

Small

Tree 4m to 8m

Shrub 50cm to 75cm

Perennial/ground cover 10cm to 20cm

Bulb 20cm to 30cm

Succulent 10cm to 20cm
Very Small

Tree 3m to 4m

Shrub 25cm to 50cm

Perennial/ground cover Up to 10cm

Bulb 10cm to 20cm

Succulent Up to 5cm

Position

Sun The area is in full sun for all or most of the day, all year round.

General Information

Drought Tolerance: High The plant is well adapted to arid conditions; it can survive long periods of drought and high temperatures without extra water.
Evergreen to semi-deciduous The plant is evergreen in warmer, wetter parts of the country, but may lose some of its leaves during winter in colder, drier situations.
Fragrant / Aromatic These plants posses a strong, usually pleasant odour.
Frost: Hardy The plant can withstand freezing temperatures or frost without artificial protection.
Roots Invasive Do not plant near pools, paving, walls or buildings.
Thorns / Spines / Prickles Thorn: A hard, woody, pointed branchlet. Spine: A modified leaf forming a hard, sharp-pointed outgrowth. Prickle: A small, sharp-pointed outgrowth growing from the bark of the plant.
Water Wise Plant species originating from low rainfall regions that require less water to survive and thrive than other plant species.
Wind Tolerant Plants able to withstand the effect of strong winds.

Specific Information

Acacia karoo has many white, paired thorns, occasionally attaining lengths of 20cm.
At least eleven varieties of butterfly larvae depend on the Sweet thorn for survival.
Depending on the climate, Acacia karoo varies from a thorny shrub to a reasonably tall tree.

Flowers

Description

scented, fluffy heads the size of a pea, in great profusion

Season

Summer Plants will seldom bloom for the entire season as given in the list, but should flower during a period within these parameters.

Colour

yellow

Growth Rate

Fast Specifying growth rate can be very misleading as there is considerable variation of growth rate depending on type and species of plant, available water, supplementary feeding, mulching and general care, as well as the plants suitability and adaptability to the garden environment.

Plant Uses

Attracts bees and other insects This plant attracts insects which can be food for birds or other creatures in your garden.
Attracts Birds This plant will attract birds.
Barrier Plant A very thorny shrub, tree or scrambler that can be used to create an impenetrable barrier.
Boundary A plant useful for planting around the edges of the property to form a green or colourful backdrop, an impenetrable hedge, to hide walls or create privacy.
Pioneer for new gardens A very fast growing plant, able to withstand hardship, that can be used to populate land that has recently been cleared of natural vegetation. These plants pave the way for slower-growing species by adding nutrients to the soil and creating leaf litter.
Provides light / dappled shade A tree with an open to sparse canopy, through which varying degrees of sunlight can penetrate.
Rock Garden An area constructed of larger rocks, arranged naturally, to emphasise the use of stones as a main element. Generally plants used do not need a lot of care.
Suitable for bonsai A shrub or tree that lends itself to being dwarfed.
Suitable for coastal gardens Plants adapted to dry, sandy soil, forceful wind, limited rainfall and intense sunlight.
Wild Garden An indigenous garden planted for the benefit of wildlife and birds. Provides food, water, a variety of mini-biomes and no poisonous chemicals are used.

Ad Break

Distribution

widespread in Southern Africa from the Western Province to Zambia and Angola, in most habitat types

Planting Suggestions

This is a difficult tree to keep in bags as the tap root is very long and the plant quickly becomes stunted. Acacia karoo is not fussy about soil types, but for maximum growth speed, prepare a good sized hole, add compost and mulch well. Water weekly until established, then fortnightly for the first year. After this, the tree can be considered water wise.

See this blog post for more information.

Medicinal Uses

An excellent fodder tree for game and livestock. Bark is used for tanning leather. The gum is edible with a slightly sour taste. The inner bark can be used for making very strong rope. A dilution of the gum is used as a mouthwash for thrush and the infused bark as a remedy for diarrhoea and dysentery.

Availability