Gibberellins are growth-regulating chemicals produced by most
plants in very small quantities. The gibberellin used by camellia
enthusiasts is gibberellic acid. The process of applying the
chemical to camellias is often called "gibbing".
Investigation of the use of gibberellins in agriculture began
in 1950 in the United States, but camellia growers did not become
actively involved in testing gib until the 1960's. The exact
process by which gibberellins work on camellias is not fully
understood. Research by U.S.D.A. scientists indicates that disappointing
results will usually be obtained when "gib" is applied
to shrubs and flowers other than camellias. The result is usually
a stretching of growth or elongation of the stems. In camellias,
the application of gibberellic acid will break dormancy of the
flower bud and enlarge the bloom size.
A solution of gibberellic acid must be applied to individual
flower buds to stimulate them into action. See illustration below.
The flower bud is plump and round where the vegetative bud is
smaller and pointed. To treat, select a vegetative bud next to
a plump, well-developed flower bud. Twist out the vegetative
bud leaving a "cup" of bud scales at the base. Place
a drop of the solution into this cup. The chemical will be translocated
to the flower bud, which should begin noticeable growth activity
within two weeks.
Testing over the years has proved the time required for a
treated bud to flower cannot be accurately pre-determined. The
general condition of the plant, the size of the flower bud, and
the weather are a few of the variables which affect the time
element. Considerable variation occurs among varieties. Early
flowering varieties may bloom within 30 days of treatment; varieties
that normally bloom late often require 60 - 90 days to open.
The time when first to apply gib differs geographically. It
is usually the end of August or the first of September before
the flower buds are well-formed enough. It is best to gib weekly
or at other intervals rather than in one session. This will ensure
that you have flowers over a longer period of time. Camellias
set flower buds only once a year, so an autumn gibbed bud will
not be replaced for spring.
The larger the bush, the more buds you can treat. Most people
like to leave about 80% untreated. Apply gib very sparingly to
a young plant. The terminal vegetative buds on treated stems
usually fail to make normal growth in the spring. Therefore,
it is usually best to cut treated flowers or to prune the stems
back.
Gibberellic acid may be purchased from the American Camellia
Society in the powdered form. It is easy to mix and comes with
instructions. One gram will treat a few hundred flower buds.
Gibbing camellia flowers buds is easy. Select well developed
flower bud, remove vegetative bud beside the flower bud and place
one drop of acid in the cup left where the vegetative bud was
removed. |
