A garden with unruly plants, left to grow out of control, will take more than a touch of weekend weeding to shape up. What's more, if those plants are invasive or can cause damage to properties, the environment and even humans, then professionals may be required to remove them.
Japanese Knotweed, for example, is considered to be an aggressive species in most of the UK, Europe, North America and parts of Oceania. There are other invasive plants that you might not have considered, too, such as English ivy, bamboo and rhododendron.