Last year I got a trailer load of manure and garden mix from a local landscape provider. I am alarmed to find that the garden is overrun with oxalis. As you know the bulbs are numerous. Will I have to pull out all my peony roses, winter roses camellias etc and start from scratch by spraying the affected garden plots with something other than my usual weed killer (which does not seem to have any effect)? Hoping to get some good advice about this dreadful problem.