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New to gardening, knockout roses have every bug

7 years ago

Hi all,

I'm a newbie and planted 2 knockout roses last fall in my garden. They have suffered severe damage this spring and I am wondering if there is something I can do (or need to do) to help them. I can live with a little bit of unsightly leaves for a while, but I want to ensure that the plants survive and thrive. I have done some searches on garden web and have some ideas but I think I have multiple issues. After looking at the plants, they seem to have EVERY kind of bug I can think of on them. Is there one that's worse for them than another? Should I treat them with something to deal with the most damaging? Are some of these bugs predators of others? Many buds are forming and blooming just fine as of now.

First the damage:

Leaves at bottom of the plant are totally eaten

Even new growth today is starting to get it (there's an ant on there too!)

This bud looks black, while most of the other buds seem ok.

Now, the wildlife:

Below are very hard to see - but they are small and white. My camera can't really focus on something this small.

Little green guys gnawing on the new growth!

Looks like a rose slug. I don't see a lot of these, but my searches suggest they are responsible for the bulk of the skeletal leaves.

Yellow guy

Flying black insect on middle left. There were a few of these hovering about.

Also saw a small daddy long legs in the middle of the bush and a tiny spider web on one small part of the same bush.

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Comments (5)

Vaporvac Z6-OhioRiverValley
7 years ago
Sawfly aka rose slug. The "fly" you showed in the last pic is the sawfly, the little "small, white" caterpillar looking thing is the slug that hatches. They apparently won't kill your roses, but are unsightly. I seem to have tons of them this year for some unknown reason.I'm removing them as well as any of the actual flies I can catch. I found them swarming on my new potted plants, as well! I don't know why your bud is black, but I hope it's not midges.
zack_lau z6 CT ARS Consulting Rosarian
7 years ago
The black bud looks like an old rose hip.
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Don't stress. I'm not quite understanding what you heard, but if you did damage the root system some its likely it will just be a bit slower getting settled. Keep it watered, but don't overwater make sure the area is draining well, and I would suggest some kind of a mulch to keep moisture from escaping long term. If anything I would suspect a bit of wilting but thats just a guess, I'm betting on it being just fine.
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There are new holes in the leaves and one bush is missing a majority of the lower leaves and no buds are forming either. Plant eating insects come in two varieties (as far as you're concerned): those that chew and those that suck. The insects that chew leave holes, but the insects that suck don't. Instead those insects either leave white spots in an intact leaf, or they distort the shape of the leaf as it's developing. Small white insects that travel far are often whiteflies, which like aphids are insects that suck; so also are leafhoppers (which are either pale green or multi-colored). If you are seeing new holes that damage is caused by an insect that chews. If you can post a good (more or less close up) picture of the insects you're seeing (& also of the new damage) I (&/or others here) might be able to provide you with an educated guess as to what you're facing now. (No promises, but for what it's worth I identify insects for a living.)
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My climate is not anything like yours (I live in eastern Washington) but I have had good luck with old fashioned shrub roses (mainly once blooming) and some hybrid musks and polyanthas (repeat blooming). I do have two yellow knock out roses (from Lowe's sale) with pink edges...and they fade to an ivory as they age. They're very pretty and I really like them. I think they look great, mixed in with lavender and pink perennials...and maybe cosmos and stock (annuals). Celsiana is one of my favorite old fashioned shrub roses. It's a damask and it blooms for a long time...four to six weeks. Here's a picture (not mine) that inspired me to get Celsiana. From Lavender's Garden Echo (Baby Tausendschon) from Rogue Valley Roses is a pretty little rose, too. I don't know how it is with humid conditions, but it does very well, in my garden. This is my picture :) From Lavender's Garden
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Wow, fairysoapgirl, that is a lot of KO roses and I love them! They are so beautiful as a hedge like that and I think those trees behind them are a great accent. I bought a one quart pot of Walker's Low Catmint because I remembered someone (I thought it was you, Rita:) mentioning it here on the forum. My search brought up this thread. I'm glad I did, because I missed the roses the first time around. That Walker's Low Catmint looks taller than I thought it would get and now I am not sure where to put it. Can someone tell me how tall it grows and how much it spreads in their garden? Also, once it's established, will I be able to take starts off of it? Thanks. Vickie
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kitasei
7 years ago
Just wait til the Japanese beetles show up!
jim1961 / Central Pennsylvania / Zone 6
7 years ago
last modified: 7 years ago
Your main damage looks like it's from sawfly larvae ( rose slugs)...worm looking things on your leaves (underneath leaf usually) holes in leaves and they leave those white marks...

Your choices are as soon as you first start seeing damage you can pick them off the bush. (In your case things are a bit out of hand now...) But you can still pick them off...

You can try spraying them off with your hose... Remember most of the time they are on the bottom side of leaves...

Some areas Rose Slugs will come and do damage for awhile and then leave...Other areas they can be there all season...Birds, wasps, will eat them...

Or you can spray Safers Insecticide soap or Spinosad following directions to a T to be effective...

Black bud??? I do not know...

I see some what looks like aphids in pic 7... Hose them off with water but be careful not to break stems etc....

Who opened Pandoras box...
dublinbay z6 (KS)
7 years ago
Just so the bush won't look so bad, you might want to pull of the worst looking leaves. New leaves will be coming before long.

And definitely clip off that old black thing.

I find I have to contend with rose slugs ("squish") for about 2 weeks, then predators of the rose slug show up and dispose of the rest. That is probably what that wasplike thing is doing there.

Remember, not all bugs as bad. Some act as "policemen" to get rid of the bad element (bad bugs) in the neighborhood.

Kate

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