Here in South Florida you can take a specimen down to Homestead at the Univ. Of Fl. TREC Research Lab and for $40 (per plant) they will do a complete analysis and give you control options. You only need to take one plant as it is $40 per plant. If another plant has something entirely different you would have to submit that and pay for each one.

https://trec.ifas.ufl.edu/


https://trec.ifas.ufl.edu/plantdiagnosticclinic/