I have a couple of large citrus trees that I planted in ground (Pummelo and Grapefruit).

I planted them a little higher than the ground level to ensure good drainage.

One thing I noted was that there are some roots (small ones, an one not so small) that are exposed on top of the ground. I guess as I have watered a bit of the roots has been exposed. Is this a big problem or normal? On the Pummelo its not too bad because the pummelo provides a ton of shade to the roots. However, the marsh grapefruit isn't as shaded and it seems like the roots on top are fairly exposed.

Just not sure this is a problem. The trees seem to be doine fine, but wasn't sure if I was supposed to add dirt, etc. I know you don't mulch on tops of the roots.

Thanks in advance for any advice.