I have owned my once 4 foot, now 5 foot tall dracaena marginata tricolor for 3 years. It has always been vibrantly healthy. A year ago, I re-potted it from a ceramic pot into a plastic pot that was two inches larger in diameter, and fertilized it with Osmocote (the only time I have ever fertilized it). I put a shredded coconut liner on the bottom thinking it would be sufficient drainage. The new growth on the top is absolutely gorgeous, but I realized it was much too wet about four months ago. Too many of the leaves turned yellow, and the tips of the rest of the mature leaves all turned black. The new growth is still beautiful, though. I drilled drainage holes in the bottom of the pot and about a half gallon of very black water drained out over the course of a week. After I drained it, I snipped the black ends off at a 45 degree angle (which I had very good success with two years ago after a move in the back of a truck shredded the ends of most of the leaves). The ends have all turned black again! What do I do?
