Rhododendrons: Newly-planted rhododendron problem

Discussion in 'Ericaceae (rhododendrons, arbutus, etc.)' started by jzenno, Oct 29, 2004.

  1. jzenno

    jzenno Member

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    Hello, this is my first posting. I planted a new dwarf rhododendron on the north side of my house. Gets partial sun and is protected by other plants. However, the borders are starting to yellow and the tips of the leaves are shriveling. I raised the plant and added peat moss, as I know they don't particularly like wet feet, but wonder if there is another problem. Any help or link you could direct me to would be appreciated.
     
  2. Bill

    Bill Active Member 10 Years

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    Be very careful with peat moss.

    Unless you mix it into the earth quite well, it will sit in pockets that actually repel moisture, and you can have half the root ball in dry peat with little water available. I use less and less peat for this reason, as the advantage of this material, water retention in dry spells (assuming proper incorporation in the soil) isn't an issue for me with regular irrigation.

    Raising it so it drains well is a good move, and all you can probably do is keep it adequately watered if it is under the eaves (nature will take care of this in BC if it is in the open) and hope that the yellowing is a normal die-back, though the shrivelling leaf tips sound a bit dire.

    There is s certain percentage of rhodos, thankfully rather small, that will die no matter how ideal the planting conditions, due to disease or previously suffered hardships, so don't be deterred by one failure, if the patient doesn't pull through.
     
  3. jzenno

    jzenno Member

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    newly-planted rhododendron problem`

    Thanks for the advice on the peatmoss. I'll remember that in the future. I did mix it in well with soil, but I did place a small layer of it just under the root ball to help raise it up. Have been watering thoroughly, too. So far, it seems to have worked. I'm trying to get the feeder roots going from the sides of the ball to work out into the soil/compost/peat mixture. The shriveling seems to have stopped. My wife thinks it might be transplant shock, but I planted other rhododendrons that have done well without any transplant shock. I will be feeding the plants a little hollytone later in November prior to the first bad frost. I'll also be mulching the plants as well to hold in moisture and spray them with Wilt-pruf, at least the newest ones. Older ones are OK. Hollies seem to need it more than the rhododendrons do because the rhododendrons have a natural moisture holding mechanism in which they curl their leaves up. Our Nellie Stevens's all but defoliated last year in the Northeast. The rhodos did fine. Will let you know how it makes out, and if it doesn't make it, I'll take your advice and keep on going!
     
  4. Bill

    Bill Active Member 10 Years

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    Depending on which plant you have, they may be semi-deciduous as well.

    All rhodos keep their leaves for a limited time - from 1 to 3 or so years, and with some it depends on the weather - sanguineum, for instance, seems to drop more the cooler the winter. Lots are shedding yellowed leaves right now.

    What rhodo are you growing?
     
  5. Ron B

    Ron B Paragon of Plants 10 Years

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    Yellowing of the leaf margins sounds like a chemical problem, like mineral salts in the water. Look up rhododendron diseases on the internet, you are likely to be able to find a web page that shows exactly the same disorder, discusses probable causes (I'd start with "oregon state university plant disease online" or a similar phrase, to get a specific one I already know about).

    Researchers do not consider amending of small planting holes to be beneficial, as it can adversely affect how water moves through the amended area. This results in reduced response from the newly planted specimen, rather than improved, until it roots into the unamended soil beyond the planting hole.

    If the existing soil is unsuitable for the plants selected, as may often be the case with specialized plants such as rhododendrons, it is necessary to excavate the entire potential rooting area and replace it with a suitable soil (or place a suitable soil on top of the existing soil).
     
  6. jzenno

    jzenno Member

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    Rhodo Problem

    So far so good. Problem hasn't particularly advanced, nor has it let up entirely. Plant still looks otherwise healthy. It is a Dora Amateis rhododendron, to answer the question posted earlier. Bought from Monrovia nurseries at Frank's garden stores. Have read some disturbing news about fungal problems with Monrovia plants, but have never had any problems with the nursery's plants in the past. Bought another one that's doing great. Have put some food down and will be mulching it in for the winter. Will be putting on Wilt Pruf this week as we've had a couple days below 30F and have seen some ice on standing water, so it's getting to be time. Thanks to all for your advice, will let you know if there are any changes.
     

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