Our yard has been overtaken (in a terrifying, apocalyptic way) by poison ivy. One of the worst places is right up under a very big oak tree. The soil is very loose, and there weren't really any plants there for a very long time, so I think it was very easy for the poison ivy to "fill the vacuum", as it were. I know of a shady place near our house where violets thrive, and I was wondering if violets might choke out our poison ivy. I don't really care if they take over the whole yard - if they don't, I know the poison ivy will. A yard full of violets sounds lovely to me, actually. Would this work? If not, what do you suggest?