This month is one of the busiest for orchid growers. Much of our success
the next year depends on what we do in the next month or so. The
temperature now is almost the ideal range for many different types of
orchids and the increasing day length is telling your orchids it is time
to grow.
Most commercial growers know that it is a waste of money fertilizing
until orchids begin to grow and this is largely temperature dependent.
Now is the time to apply Nutricote, a slow release fertilizer. It is
released once the temperature reaches about 60 F. Pay attention to the
formula that you are using and the length of time fertilizer will be
delivered. Most of the Nutricote formulas sold under the trademark
“Dynamite” are designed to provide fertilizer for six months. There are
three formulas generally available. One is a balance formula, 13-13-13
with minor elements. It comes in a red plastic container. This is ideal
for cattleyas, cymbidiums, and most other slow growing epiphytes. If you
use rainwater or R/O water there is a 9-month, Cal-Mag formulation
(15-5-9) that provides extra calcium and magnesium. Phalaenopsis and
other fast growing orchids seem to like more nitrogen this time of year,
like the 18-6-8 that comes in a green plastic container.
The real beauty of these slow-release fertilizers is that they need be
applied just once every 6-¬9 months. The only problem comes if your
orchids are potted in a very coarse medium. In this case, the small grey
pellets of Nutricote can go right through the pot or accumulate in the
bottom of the pot and not be available to the orchid plant itself.
Some hobbyists put Nutricote in little bags of cheesecloth or even embed
it in clumps of sphagnum fibers that they place on top of the medium;
anything to keep it from slipping through the medium. If you grow vandas
and ascocendas in open baskets, Nutricote can be placed in small mesh
bags and wired to the main stem just below the first leaves. Each time
you water, small amounts leak from the bag and coat the roots below
where they can be absorbed.
Many commercial growers dissolve fertilizer in their water every time
they water during the growing season. This is ideal if it is applied in
a dilute form, but is also useful if you have just repotted an orchid.
Newly repotted orchids are “hungry”, but wait until the newly repotted
orchid initiates new growth or new roots before using dilute fertilizer.
This allows damaged roots to heal before they become damp. Damaged
roots, moisture and fertilizer are a recipe for bacterial infection.
Most orchid hobbyists think that ideal conditions for orchids occur in
the middle of summer. That is also the ideal time for fungal and
bacterial growth and it is best to complete your repotting before the
intense heat arrives. This allows your newly repotted orchid to grow new
roots that can supply the plant with water when the plant is losing lots
of water from its leaves.
Many hobbyists that have kept their orchids in windows all winter are
ready to move them outside. If you have done this before you know where
they grow best. Be sure the winter has not reduced shading or that the
trees providing shade have leafed out. Invariably, orchids housed inside
all winter are burned by their first exposure to direct sunlight, even
though these might have been the same conditions they experienced last
fall. A little temporary shade may be needed.