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lam702

cutting back peonies

lam702
17 years ago

My peonies have quite a bit of what I guess is powdery mildew. I'm not sure if peonies get that, but its some kind of white powder. They tend to get it during a rainy spring. Since it's done practically nothing but rain lately, it's not surprising they would have it. I'd like to rid them of this once and for all. Can I cut them back to the ground now, and spray the stems with some kind of fungicide? Perhaps a rose dust? Would this work, or does anyone have a better suggestion?

Comments (8)

  • sammiandfargo
    17 years ago

    I am also wondering about cutting back my peonies. Mine have mildew or whatever it is too.

  • peoniesaremyfave
    17 years ago

    Everyone, I doubt this is Powderly Mildew. I would imagine that what you both have is boyritis (however you spell it), you have to cut off the leaves where it is at and throw them out. Do not put them in a compost pile just get rid of them because it is a fungil disease and it will weaken and eventually kill your peony. Do a thread search about it. Only cut the leaves/stems that have been affected by it. Leave the rest of the leaves/stems and let them die back natually to give the plant energy. You don't want to stress the poor things out anymore than they are. In the fall when the foliage is dying then you can cut the rest of the plant back to the ground.

    Good luck!

    Wendi

  • jenny_in_se_pa
    17 years ago

    Powdery mildew can be a problem on some varieties - eg., like what is happening on my Sarah Bernhardt, particularly if there has been alot of rain and humidity and a lack of air ciruclation. You'll see white powdery splotches all over the leaves. Fungicides like Daconil (or simple mixtures of milk + water or baking soda + water) can help.

    Botrytis manifests itself a bit differently, drying up flower buds and leaving water-soaked brown blotches on wilting leaves and stems, and eventually browing out the stems completely.

  • peoniesaremyfave
    17 years ago

    Hi again Everyone!

    I have to apologize, Jenny in SE PA is probably 100% correct. I am up here in NH and you are down there in PA and NY but as I noted in another thread, we have botrytis like mad up here and it is most likely because of the rain. So please do listen to her and do not listen to me. I really should have checked the zone and area before I responded to the thread.

    Jenny--once again thank you!

    hpny2 and sammiandfargo I hope things get better with your plants.

  • lam702
    Original Author
    17 years ago

    Regarding corn meal treatment: As I understand it, you sprinkle it in the beds in the spring. Wouldn't that attract mice, chipmunks and other rodents? I like the idea of cornmeal, it sounds like an organic solution but I do wonder about the animals coming to eat it. Wouldn't you exchange one problem (fungus) for another (animals eating your plants) I've had a terrible woodchuck problem, which I think I may be getting under control, but I worry that the cornmeal may attract him back into the garden. Even though he's never eaten my peonies, if he comes for the corn meal, he may rediscover my other plants.

  • maifleur01
    17 years ago

    Zone really has nothing to do with if you have one disease or another. You can have both on the same plant. The problem this year is the weather conditions. Lots of rain or humidity will form the conditions for many diseases.

    In some ways I wish zones would be dumped. The zones originally were only to show a temperature range. Certain plants will grow best at that range but too many people are being told by some authors that the zone is the most important thing to grow plants. Look at plants in your own state in the same zone, some are very different from area to area and look very happy in one and not the other. But they are in the same zone. Now off my soapbox.

    If you are worried about cornmeal you might try corn starch(the type that comes in boxes at grocery stores). It should wash down into the soil. Use a salt shaker or fine kitchen strainer but keep your face away when shaking. A breath full of corn starch or any other powder leads to a stepped on plant or worse.

    Since next spring could be dryer or wetter in your area look at what you have for mulch. If it splashes the water back on the leaves you are more likely to have fungus. If the mulch allows water to drain through it quickly the fungus will stay in the soil where it will help break down the nutriants in the soil to plant size mouthfuls. Start looking at where and how you have your plants. with the temperatures 90+ this is a good time to look with a glass of something icy in hand at what is working and plan for any moving you need this fall.

  • rosebud54
    16 years ago

    I want to know if cutting back on powdery mildewed peonies affects their bloom the following year. Can you selectively cut back- is it better and at what time of year to do it?

  • mamoo_z5
    16 years ago

    I cut back Peony in the middle of Sept in my zone 5 & the plants always flower good the next spring. I have been doing this for 12 years now without a problem. I cut mine back last week. All my plants are big older plants so I don't know if smaller or younger plants would need to be hit by frost before you would cut them back. MaMoo

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