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Starving Pin Oak Tree

Discussion in 'Homeowner Assistance Forum' started by mndbldrs, May 20, 2010.

  1. mndbldrs

    mndbldrs LawnSite Member
    Messages: 6

    I have a 10 year old pin oak with about a 3" diameter trunk that is starving for iron. I know how to set it up for a drip feed directly into the trunk. What I need is where to buy and what iron to buy to feed the tree. My neighbor has a much older cypress tree within 30' and believe it is robbing the nutrients from the ground.
  2. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,334

    How exactly have you determined this? Tissue & soil sample?
  3. mndbldrs

    mndbldrs LawnSite Member
    Messages: 6

    I live in a neighborhood that has 100-125 pinoaks and every 4-5 years, the oaks are intraveniously fed iron through a system directly into the trunk. Additionally, my tree has yellow leaves, branches with very few leaves and overall is rather sickly looking. There are not any spots on the leaves at this time. The soil is predominately a clay type soil. Other trees in the neighbor hood, once fed the iron, have a much darker green leaf and have afdditional growth.
  4. zanemoseley

    zanemoseley LawnSite Member
    Messages: 182

    You can buy liquid iron from a local co-op or farm supply. I just bought a product called Ferromec that has 6% iron I think which is also 15-0-0 Nitrogen. 2.5 gallons is about $30.
  5. mndbldrs

    mndbldrs LawnSite Member
    Messages: 6

    Does the Ferromac go into the root system or fed through the trunk?
  6. Think Green

    Think Green LawnSite Silver Member
    Messages: 2,746

    I would do a soil test and see before you spend needless time injecting iron into the tree. The pH is obviously the problem as iron chlorosis is prevalent in high acid soils. Feeding iron to a problem will not make the problem go away. Injecting the trunk yearly will damage the tree in quicker time than you know.
    I was a Mauget injector years back and don't do this stuff anymore! There is safer less damaging units out there now but the thought of drilling holes and forcing the tree to callus us the damage each time is depleting energy reserves.

    The iron product stated above is liquid and needs to be diluted in water. It is chelated iron and is available to the plant in simple form without breaking it down in the soil. The iron will bond with the metals in the soil and make it easier for root take up. You can either soil inject this stuff or foliar spray it. If you inject this material, make sure you read the labels as injection will require less material per ml. per injection site per size of the trees diameter at breast height.
    Not all materials are designed for basal injection or root flare injections.
  7. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,334

    Agreed, except that iron availability decreases with increasing pH. The source of the problem needs to be addressed.

    Well .... not really. It is ferrous sulfate, which they claim "acts like a chelate" with the nitrogen from the urea. The goal behind using chelated iron in soils is to help prevent it from reacting with other ions/organic matter, thereby keeping it in solution and plant available. The choice of chelating agent should be based on the soil conditions.
  8. Think Green

    Think Green LawnSite Silver Member
    Messages: 2,746

    When I responded earlier, my information was a bit vague as I was speaking from memory and not from my fairy tale books. So, please take this snip- it of information and do what you feel is best for you financially. Iron Chlorosis is a dominant deficiency in soils high in acid or the pH range of 7.5. I shouldn't be so inclined to know your soil type but I am sure that the tree will grow in your area but is probably not suited for your area.

    Foliar application: While foliar application of iron sulfate or iron chelate can provide a quick response, the remedy is temporary since the iron does not move beyond the actual leaves that are treated. A rate of five pounds of iron sulfate in 100 gallons of water (2.5 oz. iron sulfate in 3 gallons) is recommended. Adding a tablespoon of detergent to the mixture will help to wet the foliage. Iron chelates are water-soluble forms of iron that remain in solution, therefore available to the tree. It is best to apply foliar applications during the evening or during periods of cool weather.
    Soil application: Adding iron chelates or acid drenches to the soil can make iron more available to the tree for two to three years, but won't have a lasting effect on soil pH. Iron sulfate or a mixture of sulfur and iron sulfate can be used to make iron more available to the tree roots. Treatments are typically applied by drilling holes spaced two feet apart and 15 to 18 inches deep in concentric circles around the tree, extending beyond the dripline by about 3 feet. Common chelates available at garden centers include the trade names "Tru-Green" and "Sequestrane." Consult the labels for rates.
    Homeowners can also try to lower the soil pH by applying elemental sulfur (96%) at the rate of 2 lbs/100 square feet in April and again in September.
    Trunk injection: Tree injection systems include some available to the homeowner and others available only to professional tree services. Home injection systems include Medi-Caps and NutriBooster.In this treatment, iron sulfate, iron citrate or iron chelate is implanted in 3/8" holes 1/2" to 1" deep drilled in the tree trunk and then sealed with paraffin or grafting wax. Another method uses liquid ferric ammonium citrate applied in drilled holes or through a reservoir system. Injection treatments are most effective if applied in the early spring during bud break. However, homeowners should weigh the potential benefits from trunk injection with the potentially negative consequences caused by wounding the tree. This treatment should be reserved for high value trees.
    There are other problems like Zinc, manganese deficiencies from fruit set on these trees.
    Nut producers are lacking in these areas. Calcium problems could be another issue. Since Iron is a producer of chlorophyll in leaf production, and the lack thereof these leaves will have yellow colors with dark green vein margins. Are you sure this is the problem??
  9. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,334

    High pH, not high in acid. High acid = low pH. There are other factors as well that can account for low plant available iron, such as water logged soils, or soils high in P, Mn or Zn, irrigation water or soils high in (bi)carbonates, etc.... As your pH increases, iron solubility decreases, especially in calcareous soils. Put all these together and you have a condition in your soils that can lead to almost no plant available iron even if there is plenty of iron in the soil.

    This is not necessarily true, but generally speaking iron is considered to be a relatively immobile nutrient. I agree foliar applications are a temporary solution.

    Come on man. If you are going to copy and paste, then please link the source.


    A good reference for visual signs of nutrient deficiencies in plants can be found here.

  10. Think Green

    Think Green LawnSite Silver Member
    Messages: 2,746

    Thanks for the follow up. I wasn't trying to plagiarize any information here.

    My last paragraph was from memory and a little muddled!

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