John Mini uses a variety of plants in its color program, including anthuriums, bromeliads,
kalanchoes and a few orchid species. We use them alone in dish gardens, in combination
bowl gardens, and in open terrariums. Orchids are prized for their beautiful flowers, among
the most spectacular in the plant kingdom. As a bonus, their flower spikes last quite a while.
Orchids are distinctive and valuable plants, you will one day be tempted. Here is a review of
some basic tips to keep orchids healthy and happy.
Some Orchid Facts
The Orchid family, Orchidaceae, is the largest family of monocot plants (the clade that
includes non-woody flowering plants such as grasses, bananas, aroids, gingers, palms,
yuccas, etc.). With about 28,000 species, orchids are found on every continent except
Antarctica. Orchids can be be terrestrial, epiphytic (growing on trees) or lithophytic (growing
on or between rocks). Epiphytic orchids absorb water and nutrients with exposed fleshy white
roots. Some epiphytes even grow as vines and lianas, like Vanilla (the only orchid that is
widely consumed). In the tropics, the great majority of orchid species are epiphytes, but
many do adapt to pot culture.
Orchid flowers are considered to be the most complex among all flowering plants. Many o
the big, colorful flowers are pollinated by beetles, while the white flowers are pollinated by
nocturnal moths. In addition, there are terrestrial jewel orchids that attract pollinators with
their colorful leaves. Because their care can differ a bit, this guide will be organized by
groups.
Epiphytic orchids
Moth orchids (Phalaenopsis hybrids) The moth orchids or “phals” are the most popular
orchids we use. The parent species are native to southeast Asia through Indonesia, where
they grow low on tree trunks. Their flower spikes grow sideways—that is why we have to
stake the flower spike. Like all orchids, phals will not grow in a standard potting medium;
orchids need a loose, bark-filled mix that breathes. Many vendors that sell orchids do carry
seedling orchid bark, which is a good growing medium. These orchids are great for moderate
light locations; they grow well in big north windows or shady east windows.
You may see info that orchids can be watered with melting ice cubes. It really is better to use
room temperature water. In office settings, your watering regimen will depend on: 1)
proximity to a window; (2) your service schedule (weekly or biweekly). These orchids like to
be moist but not wet, so be careful not to overwater. Water the medium, try not to let water sit
in the plant’s crown. You can clip off the spent flowers as the plant flowers sequentially down
the spike. If you want to grow a phal long term, you can cut the old spike, and the plant
should grow a new spike in 12-18 months. As the spike grows, fertilize with an orchid food or
any plant food with a high middle number to promote flower growth. Make sure the plant food
is based on ammonia and not urea-based nitrogen—orchids and other epiphytes roots can be
burned by urea. Or you can leave the spike, and the plant will produce little plantlets where
the flowers grew. These are known as keikis (from the Hawai’ian for baby). Like all epiphytic
orchids, they should be repotted in a fresh mix no more than once a year, to avoid stressing
the fleshy roots (see below).
Tip: If you find a brown spot on an orchid leaf, try this: If the spot(s) is not too big, you can
cut it out and apply cinnamon, which seems to have real antibacterial and antifungal
properties.
Dendrobiums and Cattleyas. You will sometimes see these two genera (the plural of genus)
in our bowl gardens or open terrariums. Usually, their spikes are shorter and the flowers are
a bit smaller. However, these orchids often have even brighter flower colors, easily visible
across a large room. Where the phals grow low on tree trunks, the diverse dendrobiums grow
higher on the trunk and on shady branches. The Cattleyas are new world plants that live on
the branches in partial sun. Cattleyas are prized by orchid breeders as they can be
hybridized with other genera like Brassovola.
Both these genera need more light than phals to perform well. For the home grower, they
really are plants for big bay windows or sun porches.
Terrestrial Orchids
Lady slippers (Paphiopedilum species and hybrids). In nature, these southeast Asian plants
grow in leaf litter, on fallen logs or in rock crevices. Like the phals, these plants do not want
or need very bright light. Lady slippers are usually smaller than phals, but their care is similar.
Unlike phals, in lady slippers each crown is monocarpic—meaning that once a flower spike
dies, that crown will not flower again. However, as the spike dies, new offsets will grow off the
parent plants. Lady slippers can have bright green or mottled leaves. As a general rule, the
plants with mottled leaves can tolerate more heat; the green plants appreciate a nighttime
drop in temperature.
Jewel orchids (Ludisia discolor and Ludochilus). The most popular jewel orchid is Ludisia
discolor (discolor refers to leaves with red undersides, like many calatheas). You will
sometimes see them in our dish gardens or open terrariums. These Asian plants grow
sideways, so they do better in azalea pots or even flat bulb pans. As with other orchids, they
seem to do better long-term if they are grown in a chunky mix and not standard potting soil.
A mix of orchid bark, coir and some shredded sphagnum works well. Jewel orchids do not
like direct sun, so they grow well with phals, and tolerate even less light. There are other
genera of jewel orchids, but most need the high humidity of a terrarium or Wardian case.
However, breeders have crossed Ludisia discolor with smaller Anoectochilus species, to
produce the bigeneric Ludochilus. These colorful, compact plants can live on your windowsill,
but beware, they are slow growers. Similar to paphs, each stalk is monocarpic, but the
rhizomes will produce more stalks.
Repotting
Orchids have sensitive roots, so repotting is a bit trickier than most houseplants. If an orchid
looks pot bound, gently shake off some medium and trim only dead or damaged roots using a
clean blade. Add some fresh medium, but do not tamp firmly as you would with other
houseplants. Water if the pot feels light. Many growers try to repot only in Spring when
plants are showing new growth.
Summar
Growing orchids can be rewarding, and there are orchids for any home situation (there are
even Asian and native orchids for your garden!). Be sure to 1) assess how much light you
have, and (2) be patient!
For further reading, you can find useful info at www.davesgarden.com and
www.gardenweb.com
To learn about exotic species, you can consult Jay’s internet orchid encyclopedia at
www.orchidspecies.com
