I believe it is the buttress at the transaction between the rootstock and the Meyer lemon scion.

I could be the buttress above a whorl of roots on a rooted cutting.. they can be a different color in the transition from buttress to the final trunk diameter.

Thx for the reply. Hope this buttress is normal thing ? And what about algae, do i have to change soil ?

Hello....If that is the only soil mix you have access to then I would make sure the no bigger than an inch or less of the root ball...

When you choose a pot for that mix, there should only be enough room for your finger to fit between the pot and the root ball...This way it will dry out faster..

You could also use a wick through the bottom which will help draw moisture out and help the mix to dry..

If left like that, you will loose that tree within a year, especially through the winter.

What is the ingredients on the bag of that soil? Don't they sell perlite there? Bark mulch? Bark?

Mike

You are right Mike, I noticed in my soil there is too much peat or very fine bark mulch and very little grit or perlite stuff. I should search in the market for perlite and bark stuff otherwise I will order from Amazon
511(Bark (1/8-1/4 in) + Miracle Grow perlite + Miracle grow peat moss + Dyna gro foliage pro liquid ) Right :) ?

OR

Gritty mix 1:1:1 (Bark + Grit + turface + Dyna gro foliage pro liquid ) :) ??
Will Clay Pot makes difference in moisture control or Algae Control ?
Thanks a lot for saving the plants of whole planet :)