When any plants leaves brown at the edges that is an indication that the plant is transpiring moisture faster than the roots can supply it to the leaves. That does not always mean you need to water more, or more often, but for some reason the roots just cannot move enough water up the plant fast enough. Maybe you need to proivde this plant with some shade since I know that with air temperatures over the mid 70's I require a lot more water, especially when working, than I do with them in the mid 60's.

That's a big plant for a little pot. The above-ground leaf area is larger than the current root area can provide, regardless of how much water you lavish upon it. I'd cut a cane or two back to reduce leaf area, personally. Cut ~an inch above a bud that points in the direction you want the cane to grow.

Dan

Let it die, its an invasive species, and you shouldn't be growing it anyway.