i doubt its a media issue ...

are all the leaves on one trunk?? .. if so... i would just cut it out.. just above a leaf node.. and be done with it .. [i might see it around the plant???]

it looks like some kind of borer

i might also take it back.. implying to the store.. they are selling infected plants ... nothing like this can happen in the few days you had it.. unless the bug came home with it ...

if its disease... its the coolest patterned such i have ever seen ... such are usually more random ...

ken

Thanks for the quick reply Ken. A borer? Meaning a pest? Interesting... Good info. I will look closely to see if there's anything visible. It is on all stems, not just one. Another interesting thing is the the bottom of the leaves are fine - it doesn't go all the way through the leaves. I have attached another image of one leaf that appears to have tracks on it...

This post was edited by kray257 on Tue, Nov 25, 14 at 10:56

Leaf miner damage. If you bought them recently chances are they were already affected. I'd return them asap for a refund.

floral_uk - thank you. I looked up leaf miner and I see that the tracks are caused by that. However, it still doesn't explain the splotches from what I can tell.

It's to be part of the leaf miner damage. Read rhizo_1's post on this thread.

Here is a link that might be useful: Leaf miner on basil