Cleavers is an annual, often found in gardens and wasteland, germintating in shady areas.
It is covered with tiny hooks which helps it stick to surfaces. It can cause lodging of crops as it clambers over top and weighs them down. It is often spread by cats, dogs, and humans, as it clings well to fur and clothing.
Cleavers have shallow roots, so are easy to destroy via pulling or cultivation.
It is important to control with pesticides while still young, as it is tough to kill otherwise.