Heuchera unhappiness

Discussion in 'Annuals, Biennials, Perennials, Ferns and Bulbs' started by WesternWilson, Jun 21, 2007.

  1. WesternWilson

    WesternWilson Active Member 10 Years

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    I have noticed that all the "Marmalade" heucheras I planted last year are looking rather sorry....most are getting small, dark purple spots on the foliage, all are flopping out from the centre, and one that was not thriving I pulled, only to find white grubs dining on the roots.

    Should I just treat for grubs, or is something more serious going on?
     
  2. levilyla

    levilyla Active Member

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    I would treat the grubs...that is most likely the reason. Heucheras like very well drained soil...but moist. I have seen them in full sun and full shade doing well in both.
     
  3. Ron B

    Ron B Esteemed Contributor 10 Years

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    Weevils. The larvae also destroy primroses in summer. Sometimes a wilting specimen, that doesn't respond to watering will turn out to be a nearly rootless husk sitting on top of the ground when inspected.
     
  4. WesternWilson

    WesternWilson Active Member 10 Years

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    Thanks guys, I will try the Safer's product that kills caterpillary things!
     
  5. levilyla

    levilyla Active Member

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    I think they are pretty hard to get rid of.
     
  6. Ron B

    Ron B Esteemed Contributor 10 Years

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    Safer product probably uses Bt, don't remember this being mentioned for weevils--check the label before you waste time and money using futile approach. Apart from heavy duty chemicals know of nematodes being used on weevils.
     
  7. KarinL

    KarinL Well-Known Member 10 Years

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    Non-chemical approach to weevils: dig around in the soil where you found these, and squish all the grubs you find. If you have grubs, chances are you have adults. Look around for plants being nibbled with typical u-shaped notches in the leaves - often rhodos, hydrangeas, some herbaceous plants (I've had irises infested). Go out after dark with a flashlight to find the pests at their lunch - knock them into a container (they let go easily), dump on concrete, and stomp. On heavily infested bushes, spread newspaper or a sheet under the plant and shake the plant - most will fall off.

    One other option: put down a piece of wood or a brick under plants that are being eaten, and check it during the day - they may be under there.

    I think nematodes are recommended but I've never been sure whether they also kill beneficial beetles or not, so haven't tried them. I once tried beer traps for slugs and was sorry to find several ground beetles drowned in them, so I prefer handpicking.
     
  8. levilyla

    levilyla Active Member

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    "Go out after dark with a flash light" Dear God...just use chemicals.
     
  9. WesternWilson

    WesternWilson Active Member 10 Years

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    Anyone know what these weevils are called? I would like to look up a photo of an adult.

    I will use the caterpillar stuff to kill the grubs, hoping to save my newer heucheras as I went all out and got 5 "Obsidian" this spring (they look sooooo good grouped with "Marmalade" and "Peach Flambe").

    Thanks for the advice, and keep it coming!

    Regards,
    Janet
     
  10. KarinL

    KarinL Well-Known Member 10 Years

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    Google 'weevil'; maybe do an image search. Wikipedia's photo is not bad, but I'm sure there are better sites. They're beige to brown when young, black when older.

    As Ron said, the caterpillar stuff will not kill the grubs. It will not. No hope. It won't touch them. They will laugh it off. Use of it in this case would be ... well, I'm tempted to use a strong word here. Any chemical constitutes harm to the environment - fish, bees, and birds, among others. (It will demolish butterflies too). I can see choosing to incur that cost in order to achieve a certain task that cannot be achieved any other way. But if you are not going to achieve the task, then why ask the birds etc to carry the cost?

    If you want to defend your plants, you need to (a) use nematodes, available at any nursery, or (b) get your hands dirty and yes, go out after dark!

    There is one other tactic you can use to clear a really heavy infestation, but it is very labour-intensive and it would make more sense to use hand-picking to prevent a heavy infestation in the first place.
     
    Last edited: Jun 23, 2007
  11. levilyla

    levilyla Active Member

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    I don't go around using chemicals willy nilly...however there are some times that it seems to be the only way. I have a large garden with plenty of butterflies, bees, birds and other wildlife. Wooly adalgid on Hemlocks? The only way to get rid of them is horticultural oil..no hand picking or flashlights will do the trick.
     
  12. Ron B

    Ron B Esteemed Contributor 10 Years

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    Try searching "obscure woods weevil" and "black vine weevil" for starters. Small tan ones and larger black ones are two different species, unlike true bugs these do not have intermediate stages - they are either a grub or a fully formed adult.
     
  13. KarinL

    KarinL Well-Known Member 10 Years

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    Based on my experience I have to disagree with you Ron. I've seen the missing link - the grub morphing into the adult, like a grub with legs and the body taking form. Also using as a laboratory a container with an infestation, which is unlikely to contain several species (more like one family) the beetle form does have various stages. When the contents are dumped onto a sheet of plywood and combed through, they yield grubs at various stages and adults that are small and blond, medium and brown, and slightly bigger and the characteristic matte black.

    And I didn't recommend hand picking for wooly adelgid.
     
    Last edited: Jun 23, 2007
  14. levilyla

    levilyla Active Member

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    How would you get rid of wooly adalgid?
     
  15. KarinL

    KarinL Well-Known Member 10 Years

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    Why not start a new thread on the topic?
     
  16. Ron B

    Ron B Esteemed Contributor 10 Years

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    Coleopterans do not have instars. There is a larva which pupates, then hatches as an adult.
     
  17. KarinL

    KarinL Well-Known Member 10 Years

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    From a gardening standpoint it doesn't much matter whether it is pupating, moulting, or performing any other wonderous process of nature. Point is, as a gardener you do find the form pictured here in the centre top picture in this link as well as the one on either side.
    http://www.cfl.scf.rncan.gc.ca/imfec-idecf/ficheinsecte_e.asp?id=1726
     
  18. levilyla

    levilyla Active Member

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    and then spray with Orthene
     
  19. westcoastgarden

    westcoastgarden Active Member

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    I've moved most of my heuchera's and heucherella's to pots. They appear to be a lot happier in pots and most are now thriving including a little bitty "Iron Maiden" heucherella that languished in the ground for several years. This is its second year in a pot (about a 12 inch container) and it is large and healthy.

    I have found the yellowish heurchera's are not as healthy in general.

    My marmalade is doing ok (in a large turquoise glazed pot - it looks great) but I lost creme carmel and peach flambe/

    WCG
     
  20. Kitchen Gardener

    Kitchen Gardener Member

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    I agree with this,all my Heucheras are in pots.
     
  21. levilyla

    levilyla Active Member

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    Do you think it is because they are more well drained in pots?
     
  22. Kitchen Gardener

    Kitchen Gardener Member

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    Absolutely.
     
  23. KarinL

    KarinL Well-Known Member 10 Years

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    I don't think that you can generalize that pots are better drained. Some pots don't drain well at all, and some ground is very well drained indeed. I have plants of many sorts, including hostas and pulmonarias, that I've put in pots because they simply don't thrive in the ground, like some heucheras and heucherellas. I've postulated that in the ground they are either too exposed to pests, or not getting water directly enough to their roots. Or perhaps they can't establish well in garden soil and need a more nurturing medium.
     
    Last edited: Jul 5, 2007
  24. westcoastgarden

    westcoastgarden Active Member

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    I agree - success in pots (or directly in the ground) is about more than drainage.

    I think it is a matter of trial and error in your own garden.

    WCG
     
  25. Austen

    Austen Member

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    From my experience it sounds like you are looking at rust rather than bugs. We had a similar issue with some Heucheras we bought. They were getting weird spots on the leafs. On one of them the spots on the underside of the leaf were orange in colour. We discovered that some heucheras are more prone to rust than others. We were told to try and trim off all the leafs with the rust on them and either burn them or put them in the garbage as the rust can spread to other plants. There is a powder you can get to put on the underside of the leaves or mix with water and spray on them.
     

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