I am repotting my houseplants. When I took an areca palm out of the pot, I noticed that its roots are planted in what looks like loam. I can't identify it well, but it is very different from the normal houseplant earth I use. It is greyish-yellow, grainy and dense. It doesn't crumble at all, it smears.
I inherited the plant years ago from a neighbour who moved, and I have no idea whether it has been planted in this soil on purpose, or whether somebody without a clue has planted it in any old soil years ago. Is this good for the plant? Should I leave the roots in it and just put some new earth around as usual, or should I try to remove most of it and plant it in soft earth?