My preschooler brought home a morning glory seedling yesterday. I have a very large pot that had a palm tree in it, palm died of inadequate light and maybe some sort of issue(yellow brown lesions on the base of the fronds, but looking at it's truck mates at walmart, about half were afflicted) after just a few weeks, so I left the container sitting outside with the tree still in it thinking it might perk up. It hasn't. So if I pull up the palm, can I reuse that soil left in the container? It's a cactus/palm mix MG in there, and I'd have some fresh to mix in too. Was going to teepee the top with some dowel rods and maybe a shepards hook and put the seedling in it. I don't have access to "poor dirt", and have MG in cactus, violet and general mixes. I don't want to use the general because I want flowers, and I'm not sure what the difference is between violets and cacti requirements, so I'm not sure which I should use.

Advise please. And Thanks!