Gardening Q & A

Jan 27 2005

By The Journal

Q: a few years ago, I was given a pot of oxalis with shamrock-like leaves and pretty, lavender-pink flowers. I planted it as a shrub border where it has now become an invasive weed, even growing among the shrubs' roots. How can I get rid of it? A: Oxalis is notoriously difficult to eradicate once established. It can be killed by spraying a systemic herbicide containing glyphosate on to both sides of the leaves, though it is important to ensure the chemical does not drift on to the foliage of other plants. Two or more applications may be necessary over a period of months. The only non-chemical alternative is to winkle out the roots and the nut-like bulbils repeatedly, whenever leaf growth is seen, a process that could take two or three years.