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Yikes...problem w/citrus trunk....citrus experts?

15 years ago

I was piddling around my yard today and notice that the bark at the BASE of my pink grapefruit is cracked and chunking off in areas.

I cannot tell you how much I adore this tree.

It's being overly-shaded by a large, laurel oak that was planted by prior owners much too close. I am getting ready to call a tree trimmer to trim it back so it can get more sun.

Due to the excessive shade, the leaves have been dying and some of the bare, leaf-less branches have peeling bark. Fruit production has gone way, way down. I used to get tons of fruit - more than I could eat. Now, I 'maybe' get 2-3 dozen.

It's not being over-watered. This year, I tried the Bayer tree insecticide that GCMastiff recommends. The fruit looks prettier, but I am thinking another dose for next year will help it look better.

What do I need to do to help it? Will this bark-peeling at the trunk kill it? What is the problem? Any ideas?

Help, help, help!

Comments (19)

  • 15 years ago

    Sounds like the tree is a goner . Could be a fungus from the Phytophthora family invading the bark and trunk and causing peeling .

    This is from the UF site :
    Foot Rot (Phytophthora nicotianae)

    Lesions on a tree trunk usually occur on the bark at or just above the budunion on susceptible scions.
    The lesions will first appear as a drop of gum on the surface of the bark. Upon further investigation, a brown, discolored, necrotic, slippery area will be found under the bark. In some cases, the margin of the infected area will break away from the healthy area and may curl back. Lesions can eventually girdle the entire tree trunk .
    When the trunk is partially girdled by foot rot, the tree foliage may become dull and chlorotic, with the mid and main lateral veins of each leaf becoming yellow whereas the rest of the leaf remains nearly normal.
    Fungicides are not recommended for Phytophthora control by homeowners .

    Best bet - cut down the diseased citrus tree. Replant a new tree in a different place that gets more sun using disease resistant stock purchased from a reputable grower - not a big box store . Read and read and read some more about citrus on the U of F web site . Do not get discouraged . This happens to the best citrus growers . Imagine losing an entire grove to this !

    Here is a link that might be useful: A Guide to Citrus Disease Identification

  • 15 years ago

    Our grapefruit tree (which is now history) but did live to be over 30 years of age had a similar problem about 7 years before it gave it up. There was sap oozing out of the lower trunk. After listening to a garden show, I followed their recommendations by taking a sharp knife and gently but firmly scraping away the outer bark from the affected area until I got to the green layer underneath. I mixed up a couple tablespoons of liquid copper in about a cup of water (it's okay to make it pretty strong) and applied this mixture with a paintbrush to the affected area. This treatment can be repeated in a week. After it dries and cures, the area can be painted with white water-based paint. This procedure worked for my tree, as it lived for about 7 years follwing this episode. You might have to repeat the process a few months later, especially if the sap starts oozing out again. It can't hurt to give it a try. Also, can you trim some of the branches that are shading your tree? I wish you good success. Let me know how it turns out. Sheri :)

  • 15 years ago

    It's sad that citrus trees only live for 20-25 years normally, but that's life, I guess. The pink grapefruit next door to me died a couple of years ago. The White Marsh is still going strong. I miss the pink one, because he didn't like grapefruit, so I got all I could eat.

    The red grapefruit on the other side of me is sickly, and has no decent fruit on it. I didn't plant a grapefruit tree in my yard, and I'm beginning to wish I had.

  • 15 years ago

    Oh man....I'm so sad now! :( I absolutely LOVE my tree!

    It's a very old, well established tree. Part of the reason I bought this house was because of this tree and the other citrus trees. I had 4 in total, but one old honey-bell orange died a few years ago.

    Now that I recall -- it had the same symptoms. I remember using a copper mixture (it was green...) and painting and painting the trunk. That was my favorite tree and this pink grapefruit is my second fav. I don't even know what TYPE of grapefruit it is to plan on replacing it.

    I did replace the deceased honey-bell with a new tree. It takes soooo long for it to grow. It flowers but doesn't set fruit. I bought it two years ago and it's about 4 feet tall now.

    Jerryattreezoo: why are you recommending that I not eat the fruit after using the Bayer Tree&Shrub? I followed the directions and did not use too much. It seems a lot of folks here use it and eat the fruit. That's how I learned about it. Many professional growers use it also.
    Is there something I should know about it that I am not aware of?

    I'm calling a tree trimming company tomorrow to cut the oak back and get more sun on my grapefruit tree. I'm sure the amount of shade on the soil has helped this fungus grow. :(

  • 15 years ago

    I was taught that you use copper powder, and you mix it up into a paste and put it onto the tree after scraping off the bark. Too much copper itself will kill a tree, so it's like chemotherapy, sort of. Take it to the brink of death and see if it lives through it.

    The good news is that grapefruit trees grow very quickly. Although, I would treat the soil with boiling water a few times before I planted another tree in that same spot.

  • 15 years ago

    That honeybell may need a cross pollinator to be planted near it. Many tangerine types do.

    Also, foot rot can be caused by weed whacking up against the tree trunk. Citrus trunks are apparently very tender and any weeds should be hand pulled at the base.

    I think that your tree may just have lived out it's life span.

    I am of a certain age now, and I usually bite the bullet and shell out the bucks for larger trees in the first place. That sure cuts down on the wait time for production.

    Also, you might want to consider getting a pummelo. I love them more the grapefruit. They taste like roses and sweet lemons to me.

  • 15 years ago


    Have you thought about trying the liquid copper mixture on your tree? It really helped save mine and might just do the trick for yours also. Go back and reread my post on how to do this, if you like.

    Yes, it's true. Please do not eat any fruit from your tree after applying Bayer's Tree and Shrub spray or any other systemic spray. The insecticide gets taken up by the roots (hence, systemic) and absorbed by the leaves, and poisons the entire plant, fruits and all. I believe it might state this on the label and I've heard it emphasized by garden experts as well.

    Take care,


  • 15 years ago

    Jerry and Sheri, please note, nearly all (if not all) citrus trees being sold in Florida HAVE been treated with a systemic Imidacloprid. They are tagged with the treatment date indicated. It is to protect against Citrus Greening, leafminers, and to improve overall health. It is taken up well in the leaves, poorly in flowers or fruit. I think it is against the law to sell untreated citrus trees.

    Bayer Admire Pro is what I use now. It is a stronger version of Bayer Tree and Shrub. It IS labeled for citrus, and most veggies grown here are also treated with it or another version with the same main ingredient. Admire Pro lasts a year. What they use on veggies lasts 3 months or less. We are eating it when we buy/eat Romaine Lettuce or any other Florida grown greens.

    The Imidacloprid is not effective against fungal diseases. It only protects against leaf-eating insects.


  • 15 years ago

    Imidacloprid is a synthetic tobacco. It is supposed to be harmless, except to insects. I have used it on many things.

    As for the grapefruit tree you have, may I suggest you act stupid, just like I did. People say 'what you dont know wont hurt you', right? My grapefruit tree would do this most every fall, as if sending sap up or down to make syrup. I never knew, and still dont know for sure that its a true problem or not. I figured it is how the bark has to split and ooze in order for it to grow and expand.

    My tree did this for some 20 yrs up until the county came and took it down thanks to the canker sore problem.

    Best of luck with your tree.

  • 15 years ago


    It seems to me that anything toxic taken up by the roots would poison the entire tree. I surely wouldn't want to eat it! And it's not just my opinion, our local newspaper garden expert warns against eating any fruit from a tree that had a systemic insecticide applied to it.


  • 15 years ago

    Thanks for the advice everyone. I appreciate it.

    Tony, your citrus tree did this and recovered? I'm worried because some of the branches have peeling bark - but, I figured it's from the heavy shade canopy of the oak?

    Do all gardeners favorite plants or trees become like beloved pets to them as well? I adore this tree...I sure hope it recovers.

  • 15 years ago


    I am serious, I figured this is how the tree grows. The oozing lasted a couple weeks and then stopped and dried up. It seemed to be an annual event. The trunk had a scar where the oozing occurred, but I noticed nothing else. No decline in fruit or flavor and I still had to trim it each yr so it wouldnt tear the pool enclosure screening to shreds.

    I recall the first time it happened I did ask folks about it and they said I probably have the mulch right against the trunk of the tree, which I did. They said move it and all will be fine. Sooooo I raked it away to approx 1 ft diameter and that was it.

    Maybe what mine had was different or I was lucky, I dont know but it does sound like the same symptoms you have.

    I wouldnt pronounce it dead till it dies.

    My fingers are crossed for you and the tree..... take pics of your fav tree just in case the worst happens OR perhaps take some branches off of it and attempt to graft your tree onto other rootstock. This is one way to have your tree live on.

  • 15 years ago

    Hi Saintpfla,

    Yes, these trees and plants do become like 'children' to us after a while. We want to do all we can to insure their survival and are happier when we think they are 'happier.' :-)

    Tony is right, too. I wouldn't remove this grapefruit tree until I tried the copper treatment and/or just observe it for a while and see what happens. You are right in cutting away the branches that shade it. This will no doubt prove beneficial to the overall health of the tree.

    Take care and happy gardening! :-)


  • 15 years ago

    Several years ago I had about the same problem. I called the Pinellas County Agriculture Extension Agent, in Largo, and was told to remove the injured leaking bark, rake anything growing within three feet of the tree, keep it clean and have patience(it took a couple of years). The leaking sap stopped, the place with the scraped bark has grown back.

    I have some lower branches that the bark comes off in strips. Another call assured me that trees like people get old and not to worry about it. Duncan Grapefruit tree this year is just loaded with fruit. Not all with large fruit but not bad either. GOOD LUCK. Taste test will follow soon now!

  • 15 years ago

    That's some good info bluesky7!

  • 15 years ago

    I called a tree trimmer/cert arborist today. Murray's tree service-- in case any of you have used prior.

    He's supposed to come out on Thurs. to take a look and give me an estimate on trimming the oak.

    He said that it does indeed sound like the fungal problem that is going around Pinellas and Hillsborough currently. He said that professional growers have lost a lot of trees to it this year. It is an airborne fungus and highly contagious and will kill your tree and also spread to others.

    Definitely not good news. Today, I noticed my orange tree now has the same symptoms.

    He also recommended the copper fungicide as well, which I will definitely try (have not found any least at Lowes). But he said that it has not provided much to prevent the ultimate decline of the tree.

    I'm going to wait to see what he says further once he gets here on Thursday and will try the copper stuff. I'm not one to cut down a tree unless it is actually dead or close to it. While it is still bearing fruit and has leaves, it can stay in my yard.

    I am hoping for a miracle.... :(

  • 15 years ago

    Thanks, Watermelon.

    Saintpfla, you may find the liquid copper at a local plant nursery or perhaps, Home Depot.



  • 15 years ago

    Thanks -- I found some yesterday at a local nursery.

    I have to say, I'm more encouraged after talking to the nursery owner. He confirmed what Tony and others said here. It does seem that this is more common and that the Neutral Copper Fungicide does indeed work.

    Tree guy comes out today, so I can make plans for the oak to be cut back.

    I am feeling much more optimistic now.

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