Holoparasitic plants can be a serious danger to gardens. These plants are incapable of photosynthesis and thus cannot survive on their own. Instead, they grow in close proximity to other plants and suck away the other plant’s nutrients. While not all holoparasitic plants are killers, certain breeds do eventually kill their host plants. While some host plants prove strong enough to withstand the parasitic tendencies of the invading plant, many others will not be strong enough, and so it is important to keep a look out for these pests and to be able to recognize them. Some of the more common breeds of holoparasitic plants include toothwort, beechdrop, broomrape, and squawroot.