What is the fine-grained topic of the following text: I opted for some Snowdrops (Galanthus nivalis) at four pots for a fiver and planted them in this old clay pot of indeterminate age that I dug out of the Thames mud at Strand on the Green, where I had the good fortune to rent a room in an eighteenth century house when I first came London as a young writer. Only return the topic.
Planting Snowdrops (Galanthus nivalis) in an old clay pot from Thames mud.