How frustrating. I’m sorry to hear of the issues with your new roses.

Based on the photos and description, it looks like you have rose slug damage. They are the larvae of the sawfly and look like tiny green worms on the underside of the leaf. Once your eyes get used to spotting them, they can be easily picked off and disposed of.

Otherwise the plants look very healthy. Once the rose slugs are removed, your roses should sprout new foliage and grow away like nothing ever happened.

Thank you! Is the only cure to pick them off? Thanks

I was reading online, and found a few sprays that could work: Sevin, Bayer rose and flower spray or Eight. Any thoughts on which is best?

Tiffany, I'm 38 min. from you, just looked up my planting zone in North Aurora, it used to be zone 5a ... now I will update to zone 5b. The weather is getting warmer. Decades ago I had to buy winter-hiking boots since my feet froze walking in tennis shoes in the winter. For the past years my daughter wore tennis shoes at the bus stop, zero winter-boots like when she was younger.

Rose slug is worse when there's COMPACT clay which makes the surface always wet for sawfly larvae to hatch. Barcelona was on a raised bed and it had lots of holes like that. Dug that up and the drainage is excellent, but the clay is compact making the top soil always wet. I notice that where I mulch roses, rose-slug damage is worse since mulch keeps the surface moist for sawfly larvae to hatch. Cantigny rose park uses zero mulch for their garden, just bare dry soil. Question: Is that cocoa mulch in your pictures? Thank you. Cocoa mulch is very high in magnesium and it makes the top soil more compact, plus it holds moisture so sawfly larvae (rose slug) hatch easier. I had seen orange mold growing on cocoa mulch during week-long rain.

After 2 decades of growing 130 varieties of roses, I never use any chemical spray but treat the root of the problem first: remove the mulch which is a hatching ground for sawfly larvae (rose-slug). I did spray roses 26 years ago and I found that FIXING THE SOIL is a permanent solution, versus spraying is an expensive method which lasts for less than one week. I would remove all those cocoa mulch which holds moisture on top. Chicago Botanical Garden uses dry pine-needles to mulch their roses, which do not hold moisture for pests to hatch.

I haven’t seen pine needles in the stores.. would pine bark fines work? Unless you know of where I can get pine needle mulch?

You can spray. But for 4 rose bushes, I personally wouldn’t. It is easy enough to pick them off. In our region, rose slug outbreaks are limited to early summer only. I seldom see them again until the following year when the next batch hatches. Once your eye is trained they can be intercepted before any real damage is done. I’ve never personally used any sprays for them so I can’t answer your other question about which product is most effective.

Tiffany: In my last garden of acidic clay & poor-drainage (Glen Ellyn), I used pine-bark nuggets which last longer than pine-bark-fines. I had ZERO rose slugs and ZERO aphids on 15 hybrid-teas since the mulch was always dry. That was 26 years ago. But I had blackspots back then. In my current garden of alkaline clay (North Aurora), I tested a variety of mulch versus dry clay. Cocoa mulch is WORST for rose-slug infestation, next is wet organic matter (leaves or grass clippings). But the roses up the hill with zero mulch and it's always dry soil on top, no rose-slug damage.

Thank you both for your wise words and information! I think I will start by picking them off and then will change the mulch around the roses to pine bark nuggets if I can find them. One more dumb question: what do you do with the slugs after you pick them off? Throw them in trash? Burn them? Lol

You can squish them. Or if you would rather not, then you could put them in a small container of soapy water which can then be thrown out.

Tiffany. It's impossible to pick off ALL the rose slugs, they hide very well. I crush them with my fingers. I tried that with La reine when I mulched that rose with wet organic matter. It didn't work even when I wasted 15 min. per day locating rose-slugs. So I moved La Reine UP a DRY RAISED bed, zero mulch, and no more rose slug.

Great thank you both!

You asked about pine needle mulch sources.

Pine trees here drop their needles in early mid fall. That’s where I get my pine needles from. The trees don’t belong to me. People here discard the needles by piling them at the curb for pickup for composting.

Companies found online will ship good sized quantities to you, and make a nice profit.

Tiffany your roses look great! Just fold over the leaves & squish the larvae, no muss no fuss. Don’t worry about your mulch, whatever you have is fine. Sawfly is native to the area. I do see the small birds scarfing the larvae on my bigger roses, so avoid the sprays if you can. Sawfly info Some more info for you that discusses management.

So, I think I have a pretty substantial infestation. I went out this morning and smushed close to about 90 larvae, 50 of which were on just one plant (one of my New Dawns). About the same time I posted this discussion, I also emailed Heirloom asking for their advice. They recommended a natural spray by Dr.Earth that works as an insecticide but is made from natural oils (rosemary, cinnamon etc) and garlic. Apparently will kill the bad and preserve the good. I’m going to try it I think along with the dryer mulch just around the roses. I also have hydrangeas in the same bed and will keep the coco mulch around them. I just can’t see myself going out every morning to smush these little guys. Will post updates as they happen. Thanks again everyone

I had the same problem this spring, all of my roses got eaten, some worst then other. A rose that was on a large pot that I forgot to mulch was the worst one (planted with garden soil) so I doubt is the mulch.... I started washing the plants, like blasting with the hose to remove the eggs. I also did Neem oil that I’m not sure if it helped lol. Next year I will keep an eye early on and use insecticide soap or spinosad (seem to be an organic option) . If you keep up with washing the plant every 2 days to get all the eggs, you can decrease the population. mine are pretty much gone. Make sure to wash the underside of the leaves. But your roses looks super healthy!!

Your roses are beautiful though! What kind are they? I love how they look against the fence. Also thanks for your advice!

Tiffany: I use cocoa mulch for my "earthworm-raising". If you look at old posts back in 2012 in Antique rose forum, I did a post on the nutrients in cocoa mulch and posted a pic. of tons of earthworms raised on cocoa mulched mixed with my clay. My husband goes fishing and likes to use earthworms. I mix cocoa mulch with soil and EARTHWORMS love it, like 10 worms per one small garden scoop. Rose slugs (sawfly larvae) are worms and they feed & multiply on cocoa mulch. That's why I no longer use cocoa mulch as mulch .. back then some roses were so badly affected by cocoa mulch that ALL LEAVES were eaten.

Under my wet compost pile, there are tons of earthworms. Worms, be it rose slugs or earthworms love organic matter rich in potassium like cocoa mulch and compost. That's why I USE COMPOST ONLY IN HOT & DRY MONTHS like August & early Sept.

The years that I used horse manure (mostly dry sawdust & dry woodchips) .. I had ZERO rose-slug infestation. Only when I tested cocoa mulch that's when I got THE WORST ROSE-SLUG infestation in my 26 years of growing roses.

The 3 years I used DRY pine-bark mulch in my last house in Glen Ellyn (29 min. from your Hinsdale location) I HAD ZERO ROSE SLUG. Worms, be it rose-slug, or earthworms need moisture and nutrients to thrive, such as wet clay, compost or wet cocoa mulch. They can't hatch on DRY wood-chips. After rain, horse manure dries out faster than my black-gumbo-clay. Horse manure is mostly dry sawdust/hard-wood chips.

Ceres - wow (in a bad way)...those larvae really decimated the leaves on that bush. Dang. However, the flowers still look great and the leaves at the top of the plant look uneaten...so that's great! Oh my!!! That bouquet is gorgeous!!! I love the different shades!!!

Straw - I never thought of rose slugs coming up from the soil...I always thought the eggs must be laid on the leaves. Thanks for the heads up! :)

The rose slug larvae do not crawl up from the soil. The adult sawfly makes a slice or slit on a rose cane and lays her eggs there - sometimes you’ll see a scar on the cane. Those eggs hatch into the leaf eating larvae that cause the damage. They eat, drop off, pupated in the soil, and the sawfly hatches the following spring. We ar near the end of their breeding season here in IL. unless It’s a tiny band they generally don’t do enough damage to really harm the plant, it’s more of a cosmetic issue. I’ve never used cocoa mulch, toxic for dogs and my ya hoos would probably eat it! And I’m reluctant to use any oils for fear of leaf damage and also don’t want to nuke any beneficials.

Carol: I mentioned rose slug as Sawfly Larvae, and I mentioned "hatching" from the pupated stage. The problem with cocoa mulch: plenty of nooks for them to burrow and moisture to nourish the larvae (worms/slugs) that drop off from the plant to pupate on the ground. " Below is from University of Wisconsin, which is 2 hours from my North Aurora.

https://hortnews.extension.iastate.edu/rose-sawfly-roseslug "Larvae appear in mid to late spring (May). Fully-grown larvae drop from the plants and burrow into the soil by mid-June. They will remain dormant underground until next spring when the adults emerge and lay eggs on the new rose foliage to begin the cycle over again. Bristly roseslugs may have as many as six generations each year.

The larvae eat the soft part of leaves leaving behind the network of veins and one epidermis layer. The exposed epidermis quickly turns brown and crisp. Because the veins of the leaf are left intact the damage is called skeletonization.”

Larvae that are discovered while they are still small can be effectively controlled with any rose insecticide spray or dust. The key is to find larvae while they are still small and before damage becomes severe. There is no need for control after the larvae have finished eating and left the plants. When spraying, be sure to spray both sides of the leaf and the ground below the plant as the larvae pupate in the soil prior to overwintering. " https://hortnews.extension.iastate.edu/rose-sawfly-roseslug

Below is a picture of bristly rose slugs which may have as many as six generations each year.

I have never seen bristly rose slugs in this area. Just the more common rose slugs that only seem to be around in early summer.

Thanks, you two...I get it now. :)

Carol (rosecanadian): I love all your postings. Your questions and support for others help me to search for the truth. The only reason why I came back is YOUR WONDERFUL humble & kind spirit that uplift others. Floweraremusic (Andrea) said the same, Houzz is worth posting only because of kind & uplifting people like Carol. Our mistakes are what help others, rather than our successes.

You are such a sweet person to say that about me. It's humbling. I really appreciate you too...and so many others here.

On to the learning....anyone have any idea what these are? They lie in between slightly folded petals like chubby babies waiting for a bottle. I take them and throw them in the rocks. LOL

I'm not even sure if they're the same species.

Thanks everyone!

Carol (Rosecanadian): There are many species of worms, and I hope your white worm is not what's stated on-line: "White worm is undoubtedly the most dangerous pest for the simple reason that there is no way of knowing it's there. White worms attack the roots of the rose bush until it dies. A good way to keep them away is by keeping the soil well fertilized."

I agree with the fertilizing part, esp. giving roses enough alkaline minerals: calcium & potassium. Worm-infestation is worst in acidic soil and heavy rain that leach out minerals, making leaves thinner & curl up & more susceptible to pests.

Below link states that there are 3 species of rose slugs: "Rose sawfly: Adult sawflies emerge in early spring and lay their eggs on the underside of host plant leaves. Larvae appear several weeks later, feed on soft leaf tissue for about a month, and then drop into the soil to pupate. European roseslug sawfly (Endelomyia aethiops) produces only one generation per year, but another related species, the bristly roseslug sawfly (Cladius difformis), can produce two to six generations per year. A third species, the curled roseslug sawfly (Allantus cinctus) generally produces two generations per year. The three species are all similar in color (light green), but are easily distinguished: bristly roseslug sawflies have bristle-like hairs covering the body, and curled roseslug sawflies curl up the body when at rest."

http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/insects/sawflies/rose-and-pear-slugs-sawflies.aspx

Picture below is from above link: