Poison ivy, oak and sumac are some of the worst landscaping problems that you may have to deal with. According to specialist, more than 85% of people are allergic to these obnoxious weeds. That means that getting rid of them in our landscape and/or gardens is a must. But it also means that doing so can be risky. So, these are the important things that you need to know when getting rid of poison ivy, oak or sumac.