The Zimbabwean Gardener Issue 15 Summer 2015/2016 Low res | Page 24

Mulch

Kariba weed mulch
By Phil Vermaak

Put the invasive Kariba weed to use in the garden as a water retaining mulch.

Salvinia molesta, more commonly known as Water cabbage
or Kariba weed, is found in most waterways and dams
throughout Zimbabwe. It takes the form of cabbage-shaped
leaves floating on the water with irregularly branched stems
without roots below the water. In perfect conditions, it can
multiply every three days and, as a result, it is considered one
of the most invasive weeds in many parts of the world.

this natural form, or chopped into a more manageable size,
which makes it easier to apply around bedding plants to a
depth of 2 to 3cm.

What are the negative impacts of Kariba
weed on the environment in Zimbabwe?

Other uses

Because of its vigorous growth potential, Salvinia molesta
has an extremely negative impact on the Zimbabwean water
system. Its thick, floating carpet of growth restricts light and
oxygen to other wa