Edge browning is usually a water relations problem. Don't cut off the
browning leaves; the plant
can salvage nutrients from it.


I am going to add to your excellent post because I do not know either.
My addition to the post --

If the leaves are brown at the edges, how do I know if it is a
fungus starting on the leaves or just over watering?


Mostly edge browning indicates something like too many mineral
salts in the soil. Usual cure is leaching, especially with potted plants.


Can over watering cause the entire leaf to turn brown?

Yup. Sog out the roots and the plant dies.


I have also trimmed off the brown leaves also, still the some of my
plants have continued to turn brown and die. I have also used those
stick in the ground water dryness testers to know avail.

How hard is your water, and what are you using for fertilizer?

Kay







From some garden books I have read, it is a good thing to place
marigolds around the edge of ones garden. Applying too much water my
marigolds look awful and my tomatoes look great. Less water marigolds
look good and tomatoes seem to suffer - I cannot seem to win

My sincere apology to the original poster if I wrecked your thread.
Please answer the original posters questions first.

Enjoy Life ....... Dan