Too much sun??? Possibly too root bound? Just guessing…..

debra

For what I know, leaf damage is never recent so it is a sign of something week or two ago. Second it takes about 4 weeks for new leaf to regain maturity. For example experienced hosta growers will not send hostas till leaves have acclimated for about a month. At least that what am told.

It could be fertilizer burn.

Unless it was grossly over-applied, the Osmocote will not cause fertilizer burn. Even then, that's a stretch for a controlled release fert.

If it's been in the same container for 8 years, it might be well past time to have repotted it and refreshed the potting soil. It does deteriorate over time, drainage becomes compromised and whatever minimal amount of nutrients that were in it have been depleted. Fertilizing this season is a necessity and repot as soon as you think appropriate.

a different plant but I've had brown leaf tips on some potted peace lilies..in my case I'm pretty sure I let them get too dry..