If you own animals, particularly horses, then you should be aware of the dangers of ragwort. This dangerous weed is particularly toxic to horses, and also other animals, and once this virulent weed has become established, it can be insanely hard to get rid of. In truth, a single plant of ragwort is capable of producing as many as 150,000 seeds, threequarters of them likely to germinate if the seeds find appropriate soil. Worryingly, you may not know you have ragwort growing on your land because the seeds are able to lie domant for over twenty years.

On more weed that is peculiarly dangerous is japanese knotweed, a weed which is able to spread astonishingly rapidly and has a root system that is capable of breaking through masonry. The crazy, and amusing, thing about this dangerous plant, is that it is edible - apparently having a taste not unlike rhubarb. Still, it is a dangerous plant that must be handled as an industrial waste, as even the smallest section of its roots can grow into a whole new plant.

Japanese Knotweed comes in useful in other ways as well, for instance, it is a very good source of resveratrol, (a common nutritional supplement, which is theorized to increase longevity), and an first-class source of emodin (likewise used as a nutritional supplement to help regularize bowel movements).

If you are unfortunate enough to have either of these weeds on your property, you should act quickly, and should confer with weed eradication experts before the situation becomes unmanageable.