or there is a rent dispute where the landlord is not fixing stuff that landlords are required to have in good repair.
either way engagin in such self help is frowned upon by the law here.
There is such a thing as false imprisonment.
they would be within their rights to cicumvent the blockadge by driving over the landscaping.
I know that in the United States, at least in New York and Massachusetts, landlords can seize personal property of tennants who are in arrears, the dispostion of the property can be settled in court. In the U.S. it is next to impossible to evict a deadbeat tennant, which is why you should almost never rent property unless you throughly checkout your tennants.