Native Plants

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Sunday - November 22, 2015

From: Bakersfield, CA
Region: California
Topic: Non-Natives
Title: Containing Japanese Wisteria Roots
Answered by: Anne Van Nest

QUESTION:

I have some Japanese wisteria plants that I would like to plant inside root barriers but I cannot find any info on how deep the roots go. Do you know if a 2 ft deep root barrier for trees can contain wisteria roots?

ANSWER:

Francesco Vignoli on his Wisteria website has this to say about the roots: The wisteria roots spread so strongly and abundantly that if planted near walls or pavements they can easily grow into them causing serious damage. To prevent this from happening it is advised, whilst planting, to insert a corrugated plastic panel which will force the roots to take other directions, as they are unable to pass through it. Place the plastic panel (at least 2m long) 80cm deep, between the plant and the wall or pavement (or the surface to be protected). In the case of walls and pavements made with cement this problem does not exist.

He recommends a barrier that is almost 3 feet deep on his Wisteria website.