White spots and holes in leaves.

beffyMay 11, 2010

I am a beginning gardener in Indiana and am trying to grow everything organically. I have four rosebushes that are loaded with blooms, but the leaves don't look healthy. Lots of them have grayish-white splotches and holes in them. Many of the holes are a bit heart-shaped, or they have two humps. I have not seen any bugs on the plants at all, but I am assuming it must be either bugs or disease that is injuring the leaves. I had this same problem on another rosebush a couple years ago and never figured out what the problem was. Can anyone tell me what might be causing this damage, and also how I might be able to get rid of it without using chemicals?

Thank you for reporting this comment. Undo

It sounds like your rose bushes have fungal disease..the best way to combat this is to spray some sulfuric fungicide on it. If you want a least toxic spray, try baking soda...mix 1 tablespoon of baking soda and either 2 tablespoons horticultural oil or a few drops of dishwashing liquid detergent with 1 gallon of water. Mix as thoroughly and spray on both sides of the leaves once a week. The liquid detergent helps the baking soda stick to the leaves while baking soda changes helps create a hostile environment for the fungus to grow.

    Bookmark   May 12, 2010 at 6:42AM
Thank you for reporting this comment. Undo

Fungal diseases do not cause holes. You probably have rose slugs, tiny green worms eating your leaves from the underside. They are easily smushed. it's best to be on the lookout early to prevent too much damage.

If you need more info, I suggest you post on the regular rose forum, or on the antique rose one where there are many organic gardeners. This forum has gotten a bit strange and hardly gets any traffic.

Good Luck

    Bookmark   May 13, 2010 at 5:27PM
Thank you for reporting this comment. Undo
diane_nj 6b/7a

Insecticidal soap can also help to control rose slugs (sawfly larvae).

    Bookmark   May 13, 2010 at 7:30PM
Thank you for reporting this comment. Undo

Thanks, all, for your suggestions. I have a question for all three of you.

aero ponics, what is horticultural oil and where do you find it?

maureeninmd, would the rose slugs also cause the whitish splotches?

diane nj, what exactly is insecticidal soap and where do I get it?

    Bookmark   May 14, 2010 at 2:22PM
Thank you for reporting this comment. Undo
jean001(z8aPortland, OR)

Horticultural oil and insecticidal soap can be purchased t any garden center.

That said, no need to spray if you have only a few damagaing critters. Squishing or flicking into soapy water both work well.

Rose slugs eat the surface green off leaves. The thin tissue that remains appear to be "windows" -- perhaps the white spots you mention.

    Bookmark   May 14, 2010 at 11:38PM
Thank you for reporting this comment. Undo

maureeninmd, I think you were right. I finally found some tiny green worms on a few of the leaves. I didn't find many, but I think, by all the descriptions I've read that the culprit is rose slugs. They look really amazing under a magnifying glass! Also, when I held a white plate under the bush and shook a couple branches, there were a lot of tiny black specks on the plate. I'm wondering if they are the cocoons that they come from. It kind of looked like that under a magnifying glass.

Also, jean001, I think you're right about the white spots. The leaf is really papery thin in those areas.

The little buggers have done a lot of damage in a very short amount of time. I squished the ones I found, then put a little Ivory dish soap in a spray bottle with water and sprayed the underside of the leaves. Hopefully, that will work on the ones I didn't find.

I really appreciate all the help from you all. I've spent forever researching this, but I feel that I've learned things that will be very useful in my gardening in the future.

Thanks again!

    Bookmark   May 15, 2010 at 9:56PM
Thank you for reporting this comment. Undo
rhizo_1 (North AL) zone 7

The tiny black specks are most likely frass (poop) from the pesky chewing insects.

    Bookmark   June 14, 2010 at 11:00AM
Thank you for reporting this comment. Undo

I bought Safer Rose and Garden spray. It does not kill the bees. I called them and asked.

I am proud of you for working to learn more about gardening and what to use..especially since you are a beginner. I have been working real hard to go organic as well. I sprayed nothing last year as I kept getting conflicting reports of what is safe and what is not. What I have learned and if you learn this this year you will be ahead of where I was when I started. So many people get a few aphids and they go get a bomb spray that kills everything and treats every kind of disease for months. It's dangerous stuff. I have attended many a garden lecture and to a person they all said they use next to nothing in the way of chemicals. If you are careful with your choices of roses, sticking with healthier roses..disease resistant roses and are patient..the good bugs show up to eat the bad bugs. Having said that..I do have some roses I had to spray with Safer..and it's interesting to see that it seems like the roses that have been attacked are stressed roses..example..my minatures hardly get sun and they are in pots..any potted rose is more stressed. The rose that is not potted but has lots of bugs has two larger roses..towering way over it. So it makes sense to me. I have spent alot of time picking those rose slugs off.

I also am not above having to use an funcicide..what was recommended to me was Sulfur..wettable sulfur..it's a powder and I use a little bit and fill the container with water..and spray it. I have only done that once. Also, if you want to be organic you have to accept less that perfect looking leaves. What I do love..is all the cool birds, and bugs..and hubby even saw a garder snake yesterday. Bees buzzing around..and I love the sound of life in my garden rather than a perfect garden and the smell of chemicals all over my garden.

Stick with us..you will be glad you did...you will have a sense of pride, and your garden will be full of God's creatures.

    Bookmark   June 15, 2010 at 10:46PM
Thank you for reporting this comment. Undo

Wow Zepheris: Great advice.
Like the above poster I also have a new garden. In my case ... 1 year old. To date I've only swuished bugs. I'm visiting my plants on a daily basis and squishing what I find. So far small amounts of aphids and something called oh I forget. Little green things found in little drops of soap suds. I swuish them too. BS we have a little. I pull off and dispose of any infected leaves. So far so good. However, if I saw some major damage would not hesitate to use either of the products that Zepherisis suggested as I have researched both.
Good luck to you.

    Bookmark   June 18, 2010 at 6:44AM
Thank you for reporting this comment. Undo

Jeannie, where are u in the PNW?

    Bookmark   June 18, 2010 at 12:18PM
Thank you for reporting this comment. Undo
rhizo_1 (North AL) zone 7

What is the active ingredient in the Safer product?

    Bookmark   June 18, 2010 at 11:28PM
Thank you for reporting this comment. Undo

I notices a wasp grab and eat one of the green worms....

    Bookmark   May 18, 2011 at 3:22PM
Thank you for reporting this comment. Undo

After reading this and doing some research in one of my Jerry Baker garden books he says to hose them off with a strong stream of water and squish what you find with a gloved hand as the slugs can irritate skin. sprinkling your roses with wood ash after every rain can be very helpful as well. :-) glad I now know what's wrong with my poor rose bush!

    Bookmark   July 9, 2011 at 4:43PM
Sign Up to comment
More Discussions
So, what's Spring springing on you now?
No significant roses here yet, but... 1rst bluebonnet first...
Which Rose Do You Love/Hate?
I would love to hear about roses that drive you crazy...
Phosphorus fallacies – too much of a good thing
http://www.rose.org/phosphorus-fallacies-too-much-of-a-good-thing/ Phosphorus...
jim1961 Zone 6a Central Pa.
The Alnwick or Harlow Carr?
Replacing a "hedge" of Heritage with something...
Vinegar for black spots
I just received my Gardening Life magazine and noticed...
Sponsored Products
Amhert Mirror and Antique Silver Table Lamp
Lamps Plus
Blossom Polished Chrome Ten-Light Mini Pendant
$698.00 | Bellacor
Burgundy & Ivory Falling Leaves Microfiber Sheet Set
$17.99 | zulily
POLYWOOD Seashell Side Table
Home Decorators Area Rug: Taj Cloud 3' x 5'
Home Depot
Crystorama 4846-CT Josie Chandelier - 25W in. - Champagne Green Tea - 4846-CT
$700.00 | Hayneedle
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™