I believe no steps taken now will help.

What organism was being targeted with the spray?

I agree there's no way to fix the burns, but you did the best possible thing by rinsing off any residue from the plant. Your roses will recover and will grow new leaves.

Side note: I know this might be controversial in the US, but here in Europe Malathion has been banned since 2008. I won't go into a lecture/rant about why it's nasty, but there are many options out there that are just as effective at protecting your plants and will be safer for you, the plants, and any birds, frogs or other wildlife that lives around your garden.

Not sure why you are using the big guns when there are much safer products out there. I thought that it was banned here as well but I see it listed for sale so I guess not

I just watched a video by Paul Zimmerman. He says that if you have water, food and a place to nest, the beneficial insects will take care of aphids and stick around for the thrips.

No offense because it is your garden but you are taking out the beneficials plus the bees

Dont mean to get on the soapbox

That all being said you will get new leaves

Live and learn.

Thanks everyone for your advice! I learned my lesson in a hard way. Last year my roses almost got eaten alive by Thrips and spider mites. I found out too late and the infestation got so bad. I read somewhere that malathion is effective to treat both thrips and spider mites. So I decided to start the early treatment this year because it's going to be another hot and dry year which will be perfect for thrips and spider mites.

Any recommendation for other safe treatments? I am thinking of yellow sticky traps for thrips, and also insecticidal soap. I am afraid of using neem oil. I heard it might burn foliage as well.

I think you can usually wash off spider mites just with a stream of water from a spray nozzle attachment on a hose.

@librarian_gardner_8b_pnw Thank you! I know the best way to get rid of spider mites is water. But I feel guilty if I water too much due to the drought and water restriction. Last year I watered and washed my roses once every week. Apparently that's not enough. I have increased to twice per week this year. Will see how it works.

Agree with the above comments about Malathion being overkill for thrips. Also, aren't insecticides not useful against spider mites? Don't you need a specific miticide like Avid? I believe I've read that regular insecticides actually can make spider mites worse. Back when I used to spray the high-end fungicides regularly (>10 years ago), the only insecticide I used was a bud-only application for thrips. I sprayed it at dusk so as not to harm the bees, but with 300 roses, it was ridiculous. Now I don't spray anything, and I think my garden is overall much healthier!

@susan9santabarbara Thank you! I remember I searched for miticide before, but none of them can be shipped to California.

@KJ (9B, San Jose CA) I was surprised when you said you couldn't get a miticide shipped to Calif, so i did a Google search. Avid is not at all banned in Calif... it's actually kind of a "natural" product. Turns out that many manufacturers don't label their products with the Prop 65 warning required by Calif, and fairly recently, the time has come for full implementation. Which is why they can no longer ship to Calif. All it would take is for the manufacturer to put a Prop 65 warning on it, but I guess it's not worth it to them. It was quite the education for me in terms of Prop 65, which is controversial for many reasons :-D

@susan9santabarbara Thank you so much! I searched Avid today. Although Amazon still shows it cannot be shipped to my location, it looks like I can buy from Domyown.com. They did list Prop 65 on Domyown. Boy, it's expensive! But if it works, I will be very happy to try!

We shouldn't be using Malathion anymore. Its too toxic to Bees (doesn't matter WHEN you spray - bees come in contact with it anyway) and far too blunt a tool compared to newer insecticides that are different (more specific) in their action.

That's great to hear, Daniela. I had a bunch of thrips early June and it was frustrating on the first flush on some roses I but decided to just wait and see. Eventually, i started noticing lots of minute pirate bugs and by July i stopped having bad thrips damage. I'm hoping that my garden just naturally establishes a good balance and that the minute pirate bugs and other predator insects decided to stick around.

Not the best picture...but here's one of the welcome little fellows.

@dianela7analabama could you share where to buy adult minute pirate Bugs? I'm working from home now, so releasing them immediately wouldn't be a problem for me. Many thanks!

I think i got mine from these two sites, but it has been a while and it was a one time purchase: Arbico organic seems to have some severe weather issues right now. many other places sells them.

Besides the adults you can also buy larvae and put them out earlier. There are also other predators that may work better depending on your area. I chose these because I naturally see them around here and figured they may like it here. I guess success depends on wether they stick around. If I were you i would check to see what the natural predators of thrips are in your area and buy those then you will have a greater chance of them staying

https://www.arbico-organics.com/product/minute-pirate-bug-orius-insidiosus-predator/beneficial-insects-predators-parasites

https://www.naturesgoodguys.com/products/orius-insidiousus-500-nymphs-bottle?variant=23359008323

@dianela7analabama Thank you so very much! I will do some homework for it 😉

Hi- I’ve burned my roses pretty badly with Fungonil - called bonide - they said it’s because I used neem oil 5 Days earlier! Should I take off the leaves and prune or just wait it out? pretty awful looking!

Liz, just saw your message after I replied your thread. Don't worry. All my rose bushes which got burned were doing well later. Nothing was affected except some ugly looking leaves. What I did to try to lessen the damage is to hose them down every day.