Sure, if by "visited" you mean "surrounded the house with a helicopter, a bunch of police vehicles, armed officers and a dog". It's true that it could have been worse - it wasn't a "no-knock" raid - but it was still a raid.

And they did take some of the plant material, so "seized" seems appropriate too.

Unless the homeowner had the option of saying "Sorry, I don't grant you permission to invade my home and garden" whereupon the officers would all just go away, it was a raid.