The Tropical Fruit Forum

If a tree is to be topped, most growers top them about 28 inches.  Very soon after topping you will see side shoot growth. 

Xie Shan (pronounced She Shan) one of the earliest maturing satsuma.  In most areas the fruit is ready to eat by mid September.  As Mr. Texas wrote, Xie Shan is ready before the peel is still green.

It took a long time for citrus to reach the Mediterranean and beyond.

http://www.history.com/news/how-citrus-fruits-became-an-ancient-status-symbol

That insulated foundation just made the entire greenhouse floor a heat sink. On a sunny day it will store a lot of heat and release it into the greenhouse during the night. .

fyliu, your confusing the CCPP with the Variety Collection.   The CCPP is located inside the screen house.  Also, other people than the workers can go into the screen house, or at least used to.  I know this because my buddy and I went all through the Variety Collection and all through the CCPP screen house, and we were only tourists..

From the symptoms shown by the leaf in your photo, your tree does NOT have citrus greening. Your tree's leaves look like that because you do not fertilize the tree.  You do not say how old the tree is, but a citrus tree that is 4 years of age or older, and planted in the ground, should be fertilized three times a year during the growing season. Susanne is correct, the leaf your photo is showing is a manganese deficient leaf, also with a possibility of a zinc deficiency.  Both deficiencies have pretty much the same leaf symptoms, with the exception that zinc deficient leaves are dwarfed by the deficiency.  Never the less, when you treat for either deficiency you should treat for both at the same time.  You can foliar spray the tree with any water soluble manganese/zinc trace mineral mix.  You can also treat by fertilizing the tree through the soil with a fertilizer that contains NPK and all the trace minerals.   The probable reason that your tree did not produce as much fruit this year as last year, is due to last years crop was a large crop, plus the fact that the tree is deficient.   

http://www.fresnobee.com/news/business/agriculture/article163850083.html

http://www.archaeology.org/news/5758-170724-archaeobotany-citrus-fruit

Croxton is a pretty famous name in grapefruit.  Where did you get your tree?   McKenzie?

Mike T, your correct when you wrote "grapefruit is diminishing", as is many citrus varieties, due to Citrus Greening.  Florida production is only a shell of what it used to be, as Greening disease continually takes its toll.  Now the disease is in Georgia, Louisiana, Texas, Mexico, and now showing up in  California.  BUT --- I got my tree, and it is growing in Colorado where it is impossible for the psyllid to live.

Roots belong to the bottom portion, and not to the top portion, whether they are showing a little or not.  As far as cutting the roots, its up to you, its your tree, I wouldn't.

100% of my container grown trees are growing in Air Root Pruning Containers.  I personally believe that they are the finest containers to grow a plant in. Kvetch , its your tree, and you certainly can grow the tree anyway you wish.  One comment on the fertilizer.  If you wish to grow a container tree using organic type fertilization, its your choice.  A good conventional fertilizer with high nitrogen and potassium will be much better for your tree, but it your choice. Lastly, I would strongly recommend that you do not prune any of the tree's roots.  A citrus tree is a balance of the top foliage portion and the below ground root structure.  During the first years, there is no need to cut/prune all, or any part of the tree since research has shown that any cut to a young tree reduces root growth.  This is due to the equilibrium between foliage and root system.   A citrus tree is a biological unit.