Q) I sometimes see Dendrobiums for sale and marvel at their beauty but wonder if I can grow
them in my house. So far, I’ve had good luck with Phalaenopsis. Ashby S.
A) Most plant enthusiasts are successful with moth orchids given their low light requirements
and three month blooming time. But Phals are not without their drawbacks as some newcomers
discover. For instance, in most cases, Phals need a ‘cooling period’ to encourage their flower
spikes or one can expect just leaf growth for the year. In addition, it’s not uncommon for moth
orchids to die unexpectedly and hastily from a nasty condition called crown rot in which water is
applied improperly.
Dendrobiums offer horticulturalists delightful and long lasting blooms without the need for
cooling periods or the threat of rotting leaves. These ‘Hawaiian Lei’ orchids are grown in
fields on the Big Island of Hawaii much like corn is grown on the mainland – on a smaller
scale, in rows and by the acre. The orchids can be sold two ways – either as potted plants to
garden centers and greenhouses or as cut flowers to florists for wedding bouquets and floral
arrangements.
In addition, due to the perfect Hawaiian climate (80 degrees F day, 60 degrees F night), Dens
are available in bloom year round. Not many flowering plants can make that claim. Even the
ever-popular Moth orchids are seasonal and have to be forced or ‘tricked’ in order to bloom
any other time than late winter/early spring. When it comes to re-blooming in a more extreme
temperature zone like ours, Dens offer the element of surprise! There is no set season so they
bloom whenever they feel like it! And with any luck, it may be more than once a year!
The range of colors that Dens come in are similar to most orchids – whites, pinky/purples, and
yellows but with the addition of rusts, burgundys, blue/purples, and blushes. There are also
interesting color patterns including stripes and two tones. When it comes to flower shape, there
are two distinct styles – the round blossoms that are literally named the ‘Phalaenopsis type’ and
the twisted curly petal blooms called the ‘Antelope type’. Both styles last two months.
Here are three noteworthy and trusted hybrids that will bring joy for years to come:
1) Pegasus – this relatively compact plant (12 inch foliage) brightens any room with sturdy
sprays of round shell pink flowers. Often appearing with multiple spikes from old canes
or new, this hybrid offers an air of femininity.
2) Emma White – many imposters have been introduced in the twenty or so years since
this white hybrid first hit the market yet Emma remains the most reliable bloomer
and vigorous foliage producer. The flowers are about the size of half dollars and are
a ‘creamy white’. The leaves can approach 18 inches in length but the bloom spikes
remain fairly short which gives this hybrid a nice balanced look.
3) Thongchai Gold – there is no substitute for this striking hybrid. Large vibrant yellow
flowers with a rich velvety purple throat (two tone) characterize this amazing orchid.
Named by a breeder in Thailand.
A few cultural tips on Dendrobiums. They prefer to be potted in small clay pots with fir bark
chips and to be watered once or twice a week. Light levels are intermediate and they love being
outside for the summer.