FEATURE
Green Walls
Different basic structures have been developed over the decades, some
very simple and some more sophisticated and often imported, but the
Vicinity hardware is 100% locally manufactured in KZN and the product
was designed, locally. The electronics for the remote monitoring system
are the only imported elements. Vicinity has also collaborated with a local
manufacturer that produces LED grow lights with their lower energy
requirements for the system.
Explaining reasons for the change from the hydroponic system at EY, Strang
said that one of the liabilities of hydroponics was the small pockets of the
system, resulting in quicker dry-out, meaning higher water requirements, and
the ability to accommodate only smaller rootballs. He said the growth of the
plants was therefore impeded and the immediate effect required was not easily
attained. He added that there was seldom 100% vegetation coverage achieved.
The previous drip system used with the hydroponics had also been inclined to
drip off the leaves and splash onto the floor, out of line with health and safety
regulations.
The new system, installed by Execuflora, with the larger hexagonal pots
pre-planted by the propagating nursery, allows for more rapid maturity
and much bigger plants. No
fertilisation is needed in the
maintenance schedule because
of the big rootballs and the
adequate nutrients provided
in the potting medium. Plants
that are not doing as well as the
majority can be removed with
ease and a new plant clipped-
on as a replacement. There is
also a smaller opening in the pot
for irrigation to guard against
evaporation and this means
lower water utilisation. The
drip system connects to the pots
at the top of the structure and
water drips down from pot to
pot, gravity fed to the base. On
average, the green wall only
needs to be watered twice a week
for an hour. Excess water drips
into the sump below the wall
which is concealed by the lower
layer of plants.
Strang concludes by saying that
Execuflora is continually on the
look-out for species to trial for
their ability to tolerate indoor
conditions and to provide a
wider plant palette for green
walls.