cycl
growers know
Morse Code for Plants:
Interpreting
Internodal
Spacing
by Frank Rauscher
L
The distance
between nodes can
tell us quite a bit about
how a plant is doing.
Here’s how to decipher it.
ook at the stem of a plant and you will notice there are little
junctions called nodes. Here, the older growth creates new
growth, as this is where a new axillary bud or petiole may
emerge. In fact, it seems all the above-ground action on a plant
happens at the nodes. It is a very important place to access if
you plan to do any grafting. Also, it is at the nodes that you can
discover if your dioecious plant is male or female.
Similarly, the space between nodes, known as the
internode, can be of great interest. That’s because the length
of the internode can tell you a lot about the conditions the
plant is growing in.
Longer Internodes
When a plant is overcrowded and needs to get additional
sunlight, it will produce extra gibberellins and auxin in the
upper growth regions. These hormones cause the plant to
grow more rapidly, which in many cases will allow the plant
to better compete for the available sunlight. This more rapid
growth is what makes the internode spacing longer. When the
plant can photosynthesize at its desired rate, the hormones will
decrease and the growth rate will return to normal. However,
if light levels continue to be low at the taller heights, the
plant will continue to exhibit long internodes. This spindly,
weakened condition obviously leads to a general lack of vigor
and, often, failure to bud or bloom.
Heat is another reason that a plant may develop longer inter-
nodal spacing. In this case, the plant is trying to cool itself off by
stretching upward. Often, winter crops like broccoli will “bolt,” or
produce longer stems and flower, as a response to excessive heat.
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grow cycle