cavelight
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Brown Spots on Roses - Is this a disease?

Dear All,

I'm not sure if my knock out roses have a disease or not. Please take a look at the receptacles in this picture and let me know if the cheetah pattern is a matter of concern. I tried searching online for an answer but nothing came up.

Thanks for your time,
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Re: Brown Spots on Roses - Is this a disease?

Hi,
I edited your title to something that is more specific, or at least clearer. Hopefully that will help you get an answer.

Good luck,

;)

cavelight
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Re: Brown Spots on Roses - Is this a disease?

Many thanks. Maybe I should mention that I have been watering them in the evenings and spraying water on the leaves and roses. I read somewhere that that is the easiest way to promote disease. Is that what the problem is? So the solution is to water them in the morning and avoid spraying water at all times possible? And perhaps disposing of the leaves and roses that are brownish and dying?

Best,

cavelight
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Re: Brown Spots on Roses - Is this a disease?

Some more pictures.

I have also cut the ones that seem to be infected and I am no longer spraying water on the roses and leaves nor watering them during the evenings.

Not sure if this true or not but I also read somewhere that mixing dish soap with water and spraying them on the roses (and leaves?) acts as a good deterrent for insects.

Thanks,
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applestar
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Re: Brown Spots on Roses - Is this a disease?

Not deterrent. The solution smothers the insects -- you know how water beads? The beading action is what keeps the insect breathing pores from clogging, but soap destroys the surface tension, the water won't bead but collapses, blocking the holes and suffocating them.

So you would spray directly on the insects when you see them -- works for most -- then wait about 10 minutes and rinse the plant off.

Soap as it dries can also dedicate soft bodied insect like aphids and some insect eggs.

But you must make sure it is true soap and not dish detergent. Detergents destroy plant tissue.

Also, never spray in direct sun since the solution will then get concentrated and become too harsh for the plant.

For fungal issues, I like spraying milk solution as preventive. Safe for beneficials.
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cavelight
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Re: Brown Spots on Roses - Is this a disease?

Thanks for the great explanation, applestar. I will keep that in mind if and when I actually see insects.

All I have found so far, is very little insect webbing around the leaves and roses but I have yet to spot any insects.

Some of the stems as you can see in the pictures posted above (of pink knock out roses) have some brownish looking patches on them (doesn't look like black spot to me) and I'm not sure if they are what you call canker stems or which version of them but I can't seem to find any pictures online that are similar to mine.

I will post a picture of the stems from my other pot as well. As you can see, the stems at the base are all wooden-like (I apologise for using these amateur slash ignorant terms -- I am obviously new to all of this). Are they supposed to be like that or are they supposed to be light green? This pot seems to have many more thorns as well (it's a red knock out rose pot). I fear these roses have been infected with something that can no longer be fixed... It really hurts me to see them in this condition and to have to cut the stems and dying roses :|

I would also like to get someone's opinion about watering (evenings or mornings?) and whether spraying water is necessary or harmful.

Thanks as always,
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