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What mineral is this Oak tree  missing? (Pic)

young codgeryoung codger Posts: 543
edited August 2020 in Problem solving
I have  couple of young Oak saplings growing. One looks very healthy. The other has pale leaves. What mineral could be missing?

Posts

  • bertrand-mabelbertrand-mabel Posts: 2,697
    Magnesium?
  • young codgeryoung codger Posts: 543
    Magnesium, is that obtained straight as a chemical,  or is it only available in a type of fertiliser?
  • BobTheGardenerBobTheGardener Posts: 11,385
    edited August 2020
    It's chlorosis (lack of chlorophyll) so could be caused by a number of factors, including lack of Iron, Magnesium or Zinc.  However, there may be plenty of those elements available in the soil, but the tree could be unable to take them in because the soil pH is different to the other pot.  Read this which explains things quite well:
    There is also a possibility that that particular tree has a genetic abnormality and is unable to synthesize enough chlorophyll itself, in which case it won't matter what you do.  This is more common than one may think and is one reason that Oaks produce a lot of acorns, as many of them will produce unviable seedlings which will naturally die off in the wild.
    PS: I don't recommend you drill holes in the trunk as mentioned on that page!  That's for mature trees grown commercially.
    A trowel in the hand is worth a thousand lost under a bush.
  • young codgeryoung codger Posts: 543
    It may be a bit of trial & error to find out exactly what is missing. I have the interest, so I don't mind putting the time in.
  • LoxleyLoxley Posts: 5,698
    Make sure there's nothing wrong culturally first - as well as pH, too wet, too compacted or too dry compost can interfere with the plant's ability to uptake nutrients, as can too much / wrong sort of fertiliser (too much phosphate interferes with iron uptake).

    I note the compost level is lower in that pot. Has the level sunk? How old is the compost?

    As a general rule, I think it makes sense to be fairly frugal with fertiliser applications. I think if you try and nail down which exact element a plant is deficient in, by adding this or that element to compensate, there is a danger you end up chasing your tail and making matters worse in the process. (See the comment on BobtheGardener's link that says "Other elements such as calcium, zinc, manganese, phosphorus, or copper in high amounts in the soil can tie up iron so that it is unavailable to the plant.")
    "What is hateful to you, do not do to your neighbour". 
  • DovefromaboveDovefromabove Posts: 88,147
    Why not repot in a properly balanced growing medium for shrubs and trees such as John Innes No 3 loambased compost and see if that corrects the problem?

    Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.





  • young codgeryoung codger Posts: 543
    Dovefromabove said:
    Why not repot in a properly balanced growing medium for shrubs and trees such as John Innes No 3 loambased compost and see if that corrects the problem?
    I think repotting it is probably the way to go. If I do it in the dormant months I can remove a fair bit of the outer soil, and the tree will not be adversely  affected.
  • DovefromaboveDovefromabove Posts: 88,147
    That’s what I would do. In fact I’d probably repot both. 😊 

    Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.





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