It's neither, William! They have sent me potted irises in the past, but this time they sent rhizomes in small plastic bags with some compost so the roots don't dry out. The plants seem not to suffer at all by being treated in this way.
I don't know if they send plants like this to everyone, or if it's just local customers. I think that Lilli has bought from them in the past, so perhaps she knows?
@irislilli
I have a sister who lives not too far from Sissinghurst, so I may visit them one of these days. Thanks for all the nice comments on the order.
