Willows. A beautiful invasive specie of tree.

Willows. A beautiful invasive specie of tree.

By Lidia Boque Gousgouni
13 Sep 2017
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I’m sure you would agree with me that Willows are beautiful European trees that provide lots of shade in the summer when we’re swimming down by the river.

We have a few main species in this region, Black Willow, Weeping Willow and Crack Willow.

Black Willow has very dark and deeply ridged bark and has lots of main trunks arising from the ground. I’m pretty sure most readers would be familiar with the Weeping Willow that has big drooping strands of leaves, this is also one of the slower species of Willows as it doesn’t regenerate as quickly as the others. Crack Willow has quite straight young saplings and is quicker to split when being cut rather staying together. There are some other species around, such as the Pussy Willow and Tortured Willow which has big twists and bends in the branches which do look nice as a decorative piece when cut and dried and put in a vase.

 What many people don’t know is they’re also a very invasive species of trees, one that has been overtaking our water course edges for years. Willows produce many roots that form a thick mat like structures, these can become too thick for water to pass through and instead the water has to find a different direction of flow. This usually ends up causing erosion on the river and the creek banks.

Willows are also very smart plants because a simple stick or twig the size of your pinky has the capacity to grow its own roots and eventually become a new tree!  This is how they most commonly spread.  Branches are broken in the wind, by animals or from people playing in them, and then these broken pieces travel downstream until they get stuck in the mud somewhere and start growing.  Many species are also spread by seeds.  The Willows produce flowers in catkins, and the seed is released and germinates over summer.  So not only can the broken fragments and seeds spread hundreds of kilometers via water, the light seeds from the catkins have the potential to spread up to 100kms over land allowing them to invade off-stream wetlands.

Next week’s article will deal with the damage Willows do and what plants should be on our river banks instead.

Diary 

PLANT SALES.  The Friends of the Botanic Gardens (Albury) are open for plant sales each Tuesday and Thursday morning 9.30am – 12noon.  The Friends are also having a plant sale on Sunday 17th September 11am3pm at their nursery near the curators cottage at the gardens. All the proceeds go towards further projects in the children’s garden.

Photo

A weeping Willow bursting into growth in Wodonga.