Agriculture Reference
In-Depth Information
The'roottoshoot'ratio
The most important consideration when
selecting your plant is the health and size of
the roots in relation to the size of the shoots
(trunk, branches, leaves).
This is called the
root to shoot ratio
. In a perfect
world the volume of the roots would be
roughly equal to or exceed the volume of the
aboveground parts. This is, after all, the
pattern in well-established plants.
Most trees, however, are sold in containers
and nurtured with ample amounts of water
and nutrients so that the restricted roots can
support a shoot system much larger than that
which would occur when planted in the
landscape. Trees with a greater volume of
shoots in relation to the roots will find it hard
to draw up sufficient water and nutrients to
establish the plant quickly and successfully.
The first thing to consider when choosing a
plant is the size of the container (holding the
roots) in relation to the top growth (see
Figure 2.1).
'Bare-rooted' plants are sold when they are
dormant and have no soil around their roots.
The small, sturdy root system should be
checked for any broken or damaged roots.
Trim them back to reduce the likelihood of
infection. Take care to preserve as many
fibrous roots as possible (see Figure 2.2).
Figure 2.1
These are very tall trees for the size of their
pot. The root system is tiny compared to the amount of
shoot growth. It is unrealistic to expect these trees to
establish easily with such a small root system.
The shoots of these plants may need to be
pruned back when they are planted to
compensate any for discrepancy in the ratio
between roots and shoots. Sometimes the
shoot growth has been pruned back, but
often to an inward-facing bud. This is so the
outward-facing buds are less likely to be
damaged in transport to the nursery. Make
sure you prune the stems to an outward-
facing bud so the centre of the plant will not
become crowded (see Figure 2.3).
