I would check for Red Spider Mites. Take a white piece of paper, hold it under some of the discolored leaves, tap the leaves good, and if you have some very, very tiny spots that move show up on the paper, you have spider mites. They have been very bad here this year and have hit several of my roses. Also, look closely and see if you have very fine webs anywhere on the plants. Usually they are on the growing tip of a stem or where a stem junction at the cane is. That is another indicator of spider mites.

You can use an organic spray - I use one made by Ortho but for the life of me I can't think of the name of it right now. Sorry......I'll blame stress and age for that. LOL

Good luck.

Mary

Are there small black spots or white spots. I can't make the picture bigger with out it being blurry lol but iif so it could be fungal. You can mix baking soda with a bit of dish soap and water spray on and let dry it will help if its fungal but i think lack of water and high temps could be the problem. Un sure. Though due to my computer hating me today

Are there small black spots or white spots. I can't make the picture bigger with out it being blurry lol but iif so it could be fungal. You can mix baking soda with a bit of dish soap and water spray on and let dry it will help if its fungal but i think lack of water and high temps could be the problem. Un sure. Though due to my computer hating me today

Here is a slightly better pic of the "dots"

I was thinking some damage to leaves with holes may be rose slug damage but can not tell from pics..

This post was edited by jim1961 on Tue, Jul 1, 14 at 13:27

Spider mites. Please stop using the insecticide immediately. It does not kill the mites but does kill the insects that would naturally eat the mites thus you have a big mite population explosion. The very best thing that you can do is to buy a water wand for your garden hose and wash your roses every day for a week or so. Using the water wand, you can reach the underside of the leaves where the mites live.

Since your Knock-Outs are in a hot, dry location (ideal for spider mites), you will need to wash the foliage weekly for the rest of the summer. Good luck!

The top picture looks fine. There will usually be a couple of old leaves dying and turning yellow.

The second picture, bronzy and stippled, does look like spider mites. What Cecily says is correct--insecticides actually cause mite problems. Look on the underside with a magnifier and you should see wisps of webbing, black fecal specks, and maybe the tiny crab-like critters themselves. I would strip off any leaves that are bronzy, stippled, dry, and curling, and then wash the underside of the foliage repeatedly.

Yup. Spider mites, and as bad an infestation of them as I've ever seen.

When you spray regularly, you encourage spider mites, because you are killing all of the "good bugs" that would have eaten them up.

Here, the garden hose is your best friend. Be sure to wash the UNDERSIDE of the leaves, as that's where the little creeps congregate to do their evil work.

Did spider mites put the holes in some of those other leaves also?
Just asking as I have never peronally seen spider mite damage.

I think I might have an additional slug problem that could be causing the holes. I know we have an abundance of them here. I plan to put some beer out as a slug trap just in case.

If they are rose slugs zeroMaggie beer won't help.
Rose slugs are sawfly larvae and different from the slugs your thinking of... They are wormlike and usually found on the underside of leaves.

Maggie, the rose slugs are probably gone now. But if some of them are still there, washing off the underside of the leaves will get rid of them, along with the mites.

It's amazing -- but really, the most effective solution isn't a chemical . . . it's something as simple as water at high pressure.

To be truthful, this is a great deal of fun, on a hot summer day.