Hello good people! Let me start by saying I do not have a green thumb and know next to nothing about gardening! I purchased 4 Hawaiian Ti Red Sister plants from Home Depot about a month ago (3g pots?). This is the South Bay of So CA, about 4 mi in from the ocean, in micro-climate 10b.

Two plants went on a southward facing planter that gets clear morning sun, then dappled afternoon light from mature trees planted on a parkway. (Can't really gauge my soil type but I'd guess it's sort of "normal dirt" vs something sandy or something clayish.) When I planted the plants I used a potting soil mixed with 50% planter dirt. The south-facing plants went in the ground 3 weeks ago and mostly look good (though a few leaves have faded from greenish burgundy to yellowish, but overall not bad).

Other two red sister ti plants went in a western facing planter that is shaded by the house until noon or 1pm, then they get direct sun with some dappling late in the afternoon. These plants went in the ground just 10 days ago, and ONE of them developed quite a few yellowing leaves (6 or 7) that turned brown.... hence the picture below.

I read the soil for red sister plants should drain well and be moist without being wet (read this from the cordyline society org website). So I don't know if the soil is too moist, or if this is sun damage or what. Or just shock from being replanted?

Aside from using potting soil I also sprinkled a VERY SMALL amount of all purpose Miracle Grow pellets around the perimeter of all the plants. Like 1/2 tsp maybe around each plant. I built a drip system so the plants are watered properly and their leaves are not sprayed. And have been careful not to over-water.

One other thing... right after I planted the Ti's that went in 10 days ago (literally like the next day) we had rain followed by a cold snap that dropped into the 40s at night for about a week. And now, 10 days later, it's 85 degrees. And actually the plants are doing pretty darn good for the most part, but these handful of leaves put me on alert. I want to make sure I love them properly!

If anyone can tell me what I am doing wrong, I'd appreciate it! Thanks so much!