Grapefruit soil conditions and interior growth

[rniedz at ASRR.ARSUSDA.GOV]

On Sun, 18 Feb 1996, Paul T. Riddell wrote:

> I realize that I'll probably take grief for doing it in the first 
> place, but I have a potted grapefruit tree at home, and I need to get 
> a little more information on the tree.  (Just in case someone asks, it 
> started from a seed dropped in a pot by accident, and it's quite 
> healthy, thank you very much)  I have been unable to find any 
> information on grapefruits, in particular soil conditions, sunlight 
> needs, the necessity of spraying (after all, it's an indoor tree for 
> most of the year), and suggestions on pruning and general husbandry.  
> Seeing as how this monster is doing a charitable impersonation of 
> Audrey II (I never knew grapefruit trees had spines until this one 
> shot up), any help would be greatly appreciated.
> 
>   Cordially,
> 
>   Paul T. Riddell
>   http://www.merid.com
>   Check out our VRML page...
> 
Mr. Riddell:

First, most edible citrus types are apomictic to varying degrees, with
grapefruit being almost 100%.  This means that your tree is probably a
clone of the parent variety.  Second, citrus generally has a long juvenile
period (up to 12 years in some cases) and thorns are a juvenile trait that
disappear once the tree matures.  As an aside, the 'Calamondin' orange has
a very short juvenile period and is a popular house plant.  The
'Calamondin' is probably an orange x kumquat hybrid or a derivative of
such a hybrid. The 'Key' lime also has a short juvenile period and will
usually flower within 1 year.  As for care, there is nothing particularly
special that you need to do for a grapefruit tree, though the more light you 
can provide the better.  Pests should not be much of a problem.

Randy Niedz
USDA, ARS
2120 Camden Rd.
Orlando, FL 32803