sd...my post above is a bit different problem. Yours are mostly tips...mine is brown/blotchy spots. I am guessing yours may have gotten dry. How often do you water?

I water 2 gal every other day. If it gets into 80s, I water 2 gal every day. That's why I think watering is not my problem. I recycled some of last years potting mix, maybe some of the nutrients are exhausted.

Sun Gold in a 10 gallon will be stressed - more and more as it grows. And it will get root bound just because it is a Humongous plant.

But from the looks of the leaves I'd guess a combo of salt accumulation, N tip burn, and some sun scorching. But that is just a guess based on the pic. Need to know what all you have been feeding it and how often and what mix is in the container and what the weather has been (air temps) please?

Dave

PS: keep in mind that Smart Pots dry out 2x faster than plastic containers when it comes to watering.

Thanks Dave,

I recycled most of last years Miracle-grow potting mix. Added some organic fertilizer (about 10-1-2) and organic tomato fertilizer to the mix. After it starts fruiting, I fertilized it with Ammonium-Sulfate and miracle grow 24-8-16 fertilizer, about half table spoon per 2 gal water about once a week.

Like you said, there maybe too much nitrogen and salt accumulation. Also, the leaves facing north looks better than leaves facing south. I will try to leach some salt out of the potting mix. Thanks.