If a leaf on a plant is shriveling or yellowing, should you cut it off or leave it there? If you do the former, should you only snip off the damaged parts or should you cut off the entire leaf? My question is pertinent to young plants that may have only around 15 leaves, so each leaf is relatively important.
The only time you usually remove leaves which are slightly damaged or part dead is if the plant is highly ornamental and it's detracting from its appearance, or the leaf is damaged by some kind of infection or invader. Otherwise, just wait for the leaf to shrivel and fall off naturally, or remove it when it's at that stage.
There is always a reason for shriveling and yellowing. Taking care of the cause is the best thing for your plants health. If the leaves are dying naturally of old age, on most plants, you can cut off the leaves when the last green fades out. If the plant is disease prone or bleeds badly, wait until the leaf is entirely dry.