Last week, I replaced my two Sun Gold Cherry Tomato plants. The Sun Gold Cherry Tomato plants started to drop off fruit production a few weeks ago (see this blog entry).
From my past experience with Cherry Tomato plants (see this blog entry), I find that once the plants stop producing and it's mid-summer, it's time to put in new plants.

Hopefully, I'll have new Sun Gold Cherry Tomatoes ready to pick in late September.