Answer: It's a shame when an attractive plant becomes a pest in the garden, but it happens all the time. Since you cannot access the roots, your best course of action will be to cut back any sprouts that appear from the roots. If you diligently keep the new shoots cut down, the roots will eventually run out of energy and will die. Don't allow new leaves to spend even one day in the daylight! Eventually the roots will starve and not be able to produce any new shoots.
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