Orchid Care: How Orchids Grow
Because of the wide variety of orchid species, it's impossible
to generalize about their growing habits and preferences. It all
depends on which kind of orchid you're dealing with whether it
prefers to grow in the air, on a rock, in bark or moss or in the
soil. Orchids are divided into three different groups.
Epiphytes are the most familiar orchids for most people. They
are 'air growers', taking their nutrients from the air, though
the usually grow on and in trees. Unlike many plants that grow
in trees, epiphytic orchids are not parasites and don't harm the
plants on which they grow. Cattleya, cymbidium and dendrobium
are epiphytes, as are most of the orchids that are commonly
cultivated.
Grow epiphytes in: baskets, mounted on cork, or in loose
sphagnum moss or other planting media
Lithophytes grow on rock surfaces. Like epiphytes, they take
nothing from their growing surface, using it only as somewhere
to anchor their roots and keep from blowing away. Instead, they
get their nutrients from the air. Australian rock orchid and
eria grandis are lithophytes.
Grow lithophytes in baskets, on cork or on gravel or other
planting media.
Terrestrials are orchids that anchor themselves in soil, but
unlike most plants that root themselves on the ground - but not
in the soil. Terrestrial orchids grow in the humus - the rich,
loose top layer of soil that is made up of decaying leaves and
vegetable matter. Lady slippers and some kinds of cymbidium are
terrestrial orchids.