Rockwool provides a uniform
consistency and holds both water
and air.FLORAL FOAM - is used to make
flower arrangements. It is very lightweight
when dry, but holds a tremendous amount
of water. It is inert and easy to use. It
releases no deleterious fibers into the
environment. The problem with floral foam
is that horticultural grades come only in
small cubes. The larger blocks which are
used for floral arrangements have been
treated with a preservative which is not
good for growing plants. Before these
blocks are used they should be well rinsed
with water to remove the chemicals.
FOAM RUBBER - (such as the stuff
used for mattresses) is lightweight and
holds a lot of water and air. It is inert and
easy to use in either the block form or as
chips in a container. It can also be added to
planting mixes if chopped to pea size.
UPHOLSTERER’S FOAM - is a thin
structured foam used for furniture. It comes
in rolls and is about ½-¾ inch thick,
although it is easily compressed. It holds
ample quantities of both water and air.
Since it does not come in block form it can
be used by rolling it up firmly and placing
the cylinder in a container or by holding it