Get them out of the planters.... Never had luck doing that in Oklahoma heat....I've killed more plants than Georgia Pacific. Plus, I'm using large outdoor planters. Educate me.
They'll get a lot of sun and they're in large outdoor planters. How often to water? What kind of soil? Frequency of fertilizer? What kind of fertilizer?
Etc.
https://www.trees.com/gardening-and-landscaping/epsom-salt-for-plants