I have an anise hyssop in a pot and it hates to get dry. According to several articles I've seen, including the below, it likes moist but well-drained soil. A terra cotta pot will dry out faster than a plastic one. Some of the places it grows naturally are beside lakes and rivers and in ditches. Quoting from the below: "The pH should be 6 - 6.5. It requires lots of moisture, and wilts if it is too hot."
http://www.gov.mb.ca/agricultu...
