Rhododendrons: Am I Killing Them with Love?

Discussion in 'Ericaceae (rhododendrons, arbutus, etc.)' started by Eric La Fountaine, Sep 20, 2005.

  1. Eric La Fountaine

    Eric La Fountaine Contributor UBC Botanical Garden Forums Administrator Forums Moderator 10 Years

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    The following was received via email:

    Since purchasing an older home that is landscaped with 17 Rhododendron plants ranging in age from 1-5 year old plants, I have become an avid gardener. I am concerned however that I may be killing them with love.

    Two years ago I transplanted the bushes, encircling the front yard and in the spring the display is fantastic!! The soil I planted them in is a good mix of dark and sandy soil with a fair amount of rocks so the drainage is good. On top of the soil, after planting the Rhodo's I added approximately 2-3 inches of bark mulch. I fertilize in the very early spring, again when in full bloom and once more in the fall as advised by the local nursery with the standard Rhodo fertilizer. This year I added a feeding of Super Phosphate, again as recommended by the nursery who also said that they are 'thirsty' plants. Concerned that my Rhodo's may require more water than I was able to provide with the watering restrictions of twice a week, I buried a soaker hose approximately 3 inches below the surface and 6 inches from the base of the plants.

    I am panicking now as the lower leaves on most of my plants are turning yellow, then red, developing brown spots and dropping off. Have I committed and irreversible sin by over watering and causing root rot or can I do something to save these beauties??

    Your assistance would be greatly appreciated.

    Yours truly,
    Laura
     
  2. HortLine

    HortLine Active Member 10 Years

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    It is generally wise to under, rather than over fertilize. Never exceed the quantity suggested on the package. If you fertilize in fall, it should be late fall...once the plants are dormant. Three times a year should be very adequate!

    I assume that some of the plants are in a lot of hot sun in the summer. Yes, they do need water, and cutting down on evaporation really helps. A low ground cover can work really well. Peat moss, which is acidic, can be used to mulch and increase the water retention of the soil.

    Rhodos, while evergreen, do shed some leaves every year. So leaf loss is not necessarily a problem!

    Hopefully you will have a magnificent show next spring.
     
  3. douglas

    douglas Active Member 10 Years

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    Hi

    6 inches away from the plant maby to close for the hose.

    You should move the soaker to around the "drip line " of these plants. The drip line is +- 3 inches from the outer foliage for best results.

    Personly I would not go with peat moss as if it dries out once it can be a real bugger to re saturate and will actually pack and form a layer that also protects water from soaking down .

    Regards Doug
     
  4. Ron B

    Ron B Paragon of Plants 10 Years

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    Keep the mulch off the stems. The foliage problem may be mildew, this is very common down here.
     
  5. M. D. Vaden

    M. D. Vaden Active Member 10 Years

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    Laura,

    In what fashion did you incorporate the rocks? (the ones you referred to when mentioning drainage).
     
    Last edited by a moderator: Sep 25, 2005
  6. Joan

    Joan Active Member

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    I have noticed that my rhododendrons are losing leaves much later than usual this year. Lower leaves are turning yellow and reddish, and will shortly fall. The plants are perfectly healthy!
    Maybe there is not a problem with these loved rhododendrons !
     
  7. douglas

    douglas Active Member 10 Years

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    sound like they are happy and adjusting to mother nature
     
  8. fourd

    fourd Active Member 10 Years

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    Rhody's fine root are close to the surface, digging 3 inches deep so close, I would say a fair share of root pruning occured -- you have to be carefull with thoes shallow roots ... can easily be burned by harsh fertalizers ... over fertalization can cause problems (should only do if defficienties exist) ... rocks can cause problems ... replanting too deep could case problems ... but leaf loss could be normal ... and plants could be happy and healthy ... I would only monitor at this point.
     

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