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hsob

Problem Rose Buds

HSob
9 years ago

Hi folks,

This is my second summer in a Minnesota home. Several rose bushes came with the house and they were in terrible disregard. This spring I pruned aggressively and the plants seem to be much healthier.

My problem is that the petals on the buds are lumpy and warty - every bud, every bush. A few have opened to blooms and they are irregularly-shaped and weird. I have not noticed any bugs on the plants. Any thoughts?

Comments (8)

  • seil zone 6b MI
    9 years ago

    What kind of weather have you had? Any pretty cold nights? We were still having frosst warnings just a couple of weeks ago here.

  • HSob
    Original Author
    9 years ago

    No frost; a few hot days but otherwise temperate.

  • HSob
    Original Author
    9 years ago

    No frost; a few hot days but otherwise temperate.

  • IanW Zone 5 Ont. Can.
    9 years ago

    Sounds like "Bud blast" on your roses....

    I have cut and pasted a description of bud blast from a rose website....

    Bud blast is the drying up and failure of flower buds to open. It's a physiological condition with many possible causes, such as root injury, cold soil, high temperatures during cloudy weather, dry conditions during formation, a lack of potassium in the soil, or excessive shading. Do you think any of these conditions are present? Roses need two things for blooms: sun and nutrients. Are your plants receiving at least 6-8 hours of sun daily? Roses are heavy feeders during their bloom period. Nitrogen, phosphorous and potassium are the 3 major nutrients for all plants. (They correspond to the 3 numbers on fertilizer packages.) Nitrogen promotes growth of green leaves. Phosphorous is essential for blooms. If you are not already, I suggest you apply a rose fertilizer. The second and third numbers on the package should be higher than the first. Or, roses benefit from applications of greensand, which contains potassium, and bone meal, which contains phosphorus. Both of these nutrients are important for flowering. The thing to avoid is feeding them with high-nitrogen fertilizer that will encourage foliage growth at the expense of flowers. Keep them consistently moist and mulch with 2-3 inches of compost to help maintain soil moisture. Rosarians I know fertilize their roses every 6 weeks during the blooming season. Another possibility is rose midges--teeny, tiny bugs that cause new growth, especially buds to shrivel and turn black. Insecticidal soap can help. You might need a magnifying glass to see them, or tap a bud over a piece of white paper and see if they fall out. I hope this information helps.

  • michaelg
    9 years ago

    Rotten brown spots are caused by botrytis fungus, which attacks petals of many varieties during cool weather with fog or rain. Often flowers fail to open (called "balling"). Peel off the outer petals.

    In the aftermath of very heavy and persistent aphid infestation, petals may be warped with mottled coloring. Wash off or wipe off the aphids if they really encrust growth tips and young buds.

    Tiny insects called thrips get inside buds and feed on the petal surfaces, giving them a scratched, puffy, and soiled appearance. The picture does not look like thrips are the problem.

    More images would help us diagnose, but chances are your roses will be fine. Weather might be a factor. Fertilizer is not a factor, I can tell you with some certainty.

  • HSob
    Original Author
    9 years ago

    It could be the shade, they only get 5ish hours of sun per day. Long story short: my beds are full of river rock and none of the plants that came with the house were planted in the right spots for sun/shade. I've been shifting them to more appropriate places as fast as I can dig the rocks out but can guess how fast that is.

    Here's my plan, based on your advice (thank you so much, by the way):
    Move the roses ASAP, put them in the fanciest of soils, treat for mites and thrips.
    1) What is this plan forgetting or doing wrong? There must be something.
    2) Do you think they'll bounce back this season? How about next season?

    Thank you again for your help; it's very generous of you to take the time to help a rookie.

  • michaelg
    9 years ago

    No need to treat for mites and thrips--there's no sign of them. If you had mites, the treatment would just be to spray underneath the leaves repeatedly with water. It's unusual to find thrips being bad enough to require treatment. Agains, the image doesn't suggest thrips to me.

    Also my roses do well without extra fancy soil. Obviously you need to get rid of any large rocks. If your soil is sandy, the best additive is clay in the form of plain kitty litter, between 10 and 15% of the volume. Then did in some manure and maintain an organic mulch that will rot into the soil over the years. If your soil is clay, just add manure and avoid compacting it when it is wet.

  • jim1961 / Central Pennsylvania / Zone 6
    9 years ago

    HSOB, as long as your native soil is good enough to grow healthy plants and has good drainage I would not worry about using fancy soils...
    Unless you plan on creating raised beds for your roses...

    No need to treat for anything until you identify your exact problem...