I am wondering why my grapefruit has thick skin. It has great falvor and is very juicy but has very thick skin. This is a mature, over abundantly producing 20 year old tree. could it be a fertilizing problem? I would appreciate any answers or help that you can give me.
I've not heard of this problem but this page offers an explanation and a remedy. Your hunch of it being a fertilization problem may be correct. A review of my notes on citrus nutrition confirms an excess of nitrogen will cause fruit to produce a thicker and rougher skin with reduced juice. It will also aggravate alternate bearing in trees.
Came upon this in another document: A thick rind does appear to be the result of some sort of fertilizer imbalance. One experienced grower suggests using a fertilizer that approximates a 5-1-3 NPK ratio while others report success with 3-1-1. (e.g. a 30-10-10 formulation) The general consensus is one with high nitrogen relative to phosphorus and potassium. The fertilizer should also contain micronutrients.
Well there's another possibility. Didn't occur to me that there may not be a problem at all. Michelle, what's your idea of thick?
I did not mean to mess up your good research but she is in the right location to have one of the early Oroblanco. I believe it was released in 1980. Another thought is that the old semi-dwarf Marsh Grapefruit also had a much thicker rind than the standard Marsh Grapefruit had. One of my neighbors have one and the rind is over one inch thick, well over that in some years. Jim
No problem, Jim. Learned something in the process. I didn't follow Occam's Razor but instead assumed the rind had been thinner at one time.
Junglekeeper, let's see what Michelle comes back with but in cases like this we almost have to see what the fruit looks like before we can evaluate it. Yes, what you've written can affect the skin of the fruit when grown outdoors and if this thread dies out then start a new thread, as people will want to know what causes the skins to thicken as it can influence the quality and the sugar content of the fruit. Thick rinds is a whole other matter as some forms of Citrus can do this naturally and what may happen to my neighbor's Grapefruit tree may not be seen on others of the same type Grapefruit. It took a while for the dwarf forms to have fruit equal or close in quality to the standard form trees.. Jim
Michelle states that this particular tree is a mature 20 year old grapefruit. She fruther contributes that this tree puts forth VERY JUICY fruit with GREAT FLAVOR, and I probably would suspect rather large fruit. More importantly she states that this tree is an OVERLY ABUNDENT growing tree. Grapefruit trees that are very vigorus, strong growers, often produce fruit that have thicker than usual peels. Also, I'm not all that surprised being that this tree is also located in Palm Springs, California. - Millet
Oh boy, just what I have been looking for. About 7 years ago I planted a grapefruit tree that had Ruby Red grafted to rootstock of what I believe may be Florida Yellow, or somesuch thing. The original rootstock just took over and the ruby red is basically one fork that is, I think, a dwarf. At any rate, the Yellow is 6" in diameter and the rind averages 1 and 1/4 inches thick. The Ruby Red is roughly 3.5 inches with a rind of 11/16ths. The Yellow puts a lemon to shame - but the Red is sweet, what there is of it. The tree is prolific year around. I have constantly had to cut the original rootstock back because it puts out hundreds upon hundreds of flowers and nearly all of them fruit, and as huge as they are, hang to the ground. I have used Job Spikes formulated for citrus trees. I don't have the same problems with the navel orange, tangerines (tho lately they have been growing to the size of small oranges) or the lemons. So, if anyone has the definitive answer - I'll immediately start following a regime that will reduce the size of the rinds.
Never heard of Florida Yellow. However, the rootstock of your red grapefruit tree is probably a pommelo. - Millet