I’m growing tomatoes in big pot. Some of them turned light green with a little purple on edges of leaves. They do not look healthy like the dark green ones. They are producing tomatoes, we are in a heatwave and I water daily. What should I do to help them?
Purple leaves usually mean either phosphorus deficiency, or the plant has anthocyanin in its foliage (because some tomatoes do, albeit, not many of them). I think sulfur deficiency also adds a kind of purple look, too.
Purple leaves could also be due to cold weather, which can make phosphorus less available.