Does anyone know anything about gardening?

there's this great stuff with purple flowers I forgot the name of that
I think the Romans brought over.

Fleabane?

https://www.alchemy-works.com/erigeron.html

Now for the fleabane connection: in myth, Hephaistos tried to sexually
assault Athena, but she evaded him and his fiery semen fell to Mother
Earth, engendering Erikhthonios, a serpent-man (who became the first
king of Athens) - and fleabane. In grimoires and older magickal texts
like the Greek magical papyri, references to "semen of Hephaistos"
mean fleabane.

Just ask in the garden centre for fiery semen, they'll sort you out.