Why Blame Willows?
|Salix udensis 'Sekka' - a perfectly well-behaved
People often make reference to the invasive nature of willows. It has
been said that they can destroy water pipes, clog drainage fields and
septic tanks, crumble the foundations of homes, and that they are prone
to blow over in storms. If these factors are not bad enough, willows
are also messy with catkins dropping in the spring and leaves falling
in the autumn.
While it is true that some vigorous growing willows can do some of
these things, is all of this blame on willows really warranted? For
instance, with regard to their falling over in storms, willows, with
their quick-growing roots, are actually less likely to blow over compared
to many of the shallow rooted trees. A good example is Blue Spruce (found
on many suburban lots) which have a much higher risk for windthrow.
As to the notion of destroyed pipes and foundations, if pipes are leaking
and foundations have cracks, willow roots will take advantage of these
available resources. However, the same could be said for many other
large trees and shrubs. Willow roots cannot drill holes in pipes nor
damage solid foundations.
Whenever there is some uncertainty, especially around older homes and
exterior plumbing, it is prudent to be cautious when planting willows.
Also, it is wise not to plant any water-loving trees on or near septic
tanks and drainage fields.
|Salix nakamurana var yezoalpina - an alpine
willow that remains low to the ground
Keep in mind that the genus Salix is a large and diverse plant group
with nearly 500 species. Only a few are responsible for their bad reputation.
Unless the area can accomodate large trees, avoid using Salix alba
(White willow), Salix fragilis (Crack willow), Salix babylonica
(Weeping willow), Salix nigra (Black willow) and the others
that become large shrubs.
Coppicing (pruning back to the ground
each year) will keep the roots of the large and medium willows in check.
With less top growth providing energy to the roots, the root size is
correspondingly less. City gardeners can enjoy many of the brightly
coloured basketry willows by giving them this annual pruning.
It is certain that as willows become more popular and well-known, many
more of the small and alpine types will become available.