Winter – A Time to
Flower and Rest
inter can seem like a conflicting time in
the nursery; we have many plants that are beginning to bud and flower, and
many that are beginning to rest in preparation of flowering, or resting to
recover from flowering.
As any experienced orchid grower can attest
to, cycles are all important in growing many orchids, and understanding how
the cycles of different orchids work is the key to growing them well. There
are three main parts to every orchid’s growth cycle: active growth,
flowering, and resting. These parts of the cycle can arrange themselves in
different orders for different genera of orchids, and some even have
multiples of each part.
The most common arrangement of the parts of
the cycle is growing, flowering, resting, and then growing again. We see
this in many of the hybrids of the most common genera, such as Oncidiums,
Cattleyas, and Phalaenopsis. There are always exceptions to the rule, but
for the most part the hybrids will hold true to this cycle.
The parts of this cycle are often closely
entwined with the seasons. Spring is the season when growth begins, as
plants finish flowering and resting and the change to more amicable
temperatures and light signals the start of the growing season. Summer is
often the season of active growth, when the largest amount of water,
nutrients, and light is available, and when temperatures accelerate plant
metabolisms. As the fall approaches, and temperatures begin to drop, this
signals the end of the growing season, and in many cases initiates spiking
as growths harden off and mature. (This is especially true of Cattleyas;
nearly 2/3 of all of our Cattleya hybrids have been budding and blooming
since the start of November). Winter is the time of flowering, and as
flowering ends, the time of resting.
This being said, each of the main genera
has its own alignment that is slightly different from the rest. For example,
our Oncidiinae hybrids usually begin spiking towards the end of summer into
November, resting early, and beginning growth as soon as the daylight hours
increase again. Our crop of Phalaenopsis begin to spike in November, will be
flowering from now until March or so, will rest around April, and then begin
to actively grow in June (which reflects their love of warmth).
An example of a plant like
these is Cattleya percivaliana ‘Christmas Cheer’, which budded towards the
end of December to flower around Christmastime. From spring until autumn,
this plant grows, with the growths producing sheaths as December approaches.
They flower and then rest for a month or two before beginning active growth.
We water less in the winter because it takes longer for the pots to dry out,
but we don’t intentionally limit the water to this plant, so any incidental
decrease in water is naturally occurring. This is a metabolic rest, as
opposed to an environmental rest.
But not many of the hybrids
from these genera have what you might term as hard rests; meaning that their
metabolism slows down, but we do not change the input of water, nutrients,
etcetera any more drastically than warranted by the change in weather. There
are many plants however, that will rest much harder than these and require
cool, dry periods of as long as three months (five months including the
gradual decrease and increase of water, nutrients, etcetera) in order to
grow well and flower.
Some of the more common of the harder
resting genera are: Dendrobium, Cycnoches, Catasetum, Lycaste, Habaneria,
and Cymbidium. Many of the plants in these genera (but not all!) will only
receive a light misting about once every week or two (or even less), until
spring. The two hardest months of rest for us are December and January,
using November and the end of February into March as transition months.
A good example of a hard
resting plant is Cymbidium Little Black Sambo. This plant requires at least
two months of near dryness in order to initiate flowering. From the
beginning of December to the end of January this plant will receive nothing
more than a sparing misting every now and again to ensure the root system
doesn’t die completely and the bulbs won’t shrivel excessively. Otherwise,
it will be cool and dry. It is also an example of a different order in the
cycle; it rests before flowering, and then resumes growth directly after it
has finished flowering.
At first growing plants that have a harder
rest period may seem daunting and intimidating, however these are actually
some of the easiest plants to grow as it is obvious when they need to rest
and require far less attention during that period. If you have ever been
cautious about growing a plant that goes dormant or requires a hard rest, I
encourage you to check out some of the literature below and try one of these
wonderful, rewarding genera.
The scope of this article is far too small
to go into any in-depth analysis of the resting of even the more common
genera; however there are some very good books out there that are dedicated
to these genera, and are well worth the read. I have listed some that have
been of use to me below.
Home Orchid Growing, by Rebecca Tyson Northren
Any of the Books by Baker and Baker, compiled online at
The World of Catasetums, by Arthur W. Holst
Growing Orchids, by J.N. Rentoul
Lycaste Species, The Essential Guide, by Dr. Henry F. Oakeley
Cycnoches, Orchids Magazine Supplement, Multiple Authors