I'm very much a layman at gardening. What is a "rough lemon rootstock"?

How could it be getting too much nitrogen? I just feed it citrus food.
Sometime I put nitrogen fertilizer on the lawn, but that is a small portion
of the area under the tree.


"omi" wrote in message
news
"G Burton" wrote in message
...
The lemons on my tree have very thick skins and the fruit is extremely
sour. I live in zone 14. The tree had been neglected for at least 5
years and was badly infested with scale, but that is under control now. I
thought that it might be a bad variety of lemon, but my local nurseryman
looked at one of my lemons and told me that was not the case. He also
told me that thick skins and sour fruit go together and are both symptoms
of a tree that is starved of minerals. He then sold me and iron, sulfur,
manganese, zinc mixture called F.S.T. I am also feeding it Citrus food.
Well I have been tossing down a handful F.S.T. and citrus food once
every 6 weeks for about a year now, but the lemons are still horribly sour
and the skins are still thick. Much of the roots are under our lawn, so I
have been spreading F.S.T. and citrus food on my lawn as well, but it
doesn't seem to hurt it. Our soil is heavy clay. It may just be that it
takes a very long time for the F.S.T. and citrus food to work its way
down, but I was hoping for results by now.
Opinions and suggestions please.

Thick skins are often due to too much nitrogen. Could it also be due to
shoots from a rough lemon rootstock that have taken over? Olin