Is there any chemical application which will successfully kill off the tubers of smilax or will it just effect the above ground vegetation?
Glyphosate plus a penetrant should do it.
Have a look at what Weedbusters say about it. Sounds as though you'll need to follow up. If the spray will hit tree trunks don't use penetrant.
Ive used on Asparagus scandens,Meturon,Glyphosate and Organosilicone with good results.More than one treatment is required though,should work well with this too.
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