First I would identify the problem and the choose a variety that combats that problem. I grew Cal Wonders with no problems untill I bought a couple of replacement plants and introduced Mild Mottle Virus. I trial a lot of different varieties and thus far Socrates has been the best replacment for Cal Wonder. I also get good performance from a green to yellow variety Aladin. Another green to red that did pretty well was Crispy. A pleasant surprise was the dark purple/black to red Mavras. Striking visual and a decent performer.
