It is very serious. All of a plant's energy is manufactured in the leaves. If the leaves are sick or fallen, the plant can only grow by burning stored energy. Repeated defoliation uses up most of the stored energy so the plant cannot bloom, harden up for winter, or come back after winter.

The consequences are worse with more susceptible varieties, less vigorous varieties, and plants growing in cold-winter areas.

Double Delight is no worse than average for a hybrid tea and is easily kept clean by a normal fungicide regimen. There are probably only a handful of hybrid teas (if that many) that can be grown reasonably well without fungicide in a rainy climate.

I grow Double Delight cause I think it is a great rose! The color combination is great and that smell is fantastic. I use Bayer Rose Disease Control. If you start as soon as the leaves come out, and spray every 10 days, you will have clean roses.

As the poster says above, I do think it weakens the rose, even if it doesn't kill it. I don't get rid of any with blackspot automatically--most of my roses get some blackspot by August, I'm not a very good consistent sprayer--heck, I'd have no roses left besides KO's. So the deciding factors for me in getting rid of a diseased rose are: how severe and how frequent does it come down with BS? If it defoliates all over the bush all summer long, every year (Iceberg, Sunsprite), it's gone. If it gets a little and shrugs it off and keeps growing and doesn't go totally naked, it stays.

My experience in my 1000 rose, zone 5, inland, northern Ohio, rose garden is that after about 5 years of no-spray that the blackspot problem takes care of itself (an equilibrium of good bugs - bad bugs has been reached). Of course this does not help the exhibitor who must have perfect leaves and may not apply in much more humid climates.

Where you live also has a huge impact upon how important black spot is for you. In the Mid-Atlantic region it really flourishes because the climate during the growing season includes at least two months of warm to hot, sticky days that are pretty much in the perfect temperature and humidity ranges for black spot to be at its worst. A defoliated rose may not make it through a severe winter because it won't have the starches stored that it will need to recover the following spring.

I used to live in the Philadelphia area and grew Double Delight. I sprayed it for black spot and it thrived. After I moved away my folks didn't do any spraying and the rose continued to grow, but bloomed far, far less. (They also didn't fertilize it and that most likely had the larger impact.)

Where I live north of Boston I'm right on the ocean. Here the summer climate is moderate to cool with just a few weeks of hot weather, but it's always humid. I grew one Bourbon rose here (Madame Pierre Oger), not realizing it had a reputation for being prone to black spot. The flower was an outstandingly lovely pink, but the flowers struggled to open in the cool, humid weather and the plant defoliated badly from black spot. After three years a severe winter killed it. Here I do not regularly spray for black spot, and when I do spray I don't use anything more powerful than sulfur. From what I understand sulfur works better as a deterrent than it does once black spot has appeared on the leaves. It does appear to slow black spot down, but it doesn't stop it altogether.

As you read you'll see some contributors will give you detailed information about their black spot experiences with roses they've grown.

Please help me identify a rose. Could the one in the picture below be a double delight rose? It is grown in Boston.

Here is a link that might be useful: PICTURE

That looks like Gemini to me. DD is red and cream.

Folks, please try to keep the spraying to a mimimum. It kills the BEES..we desperately need bees

Although BS is not a serious problem here, it would be in a more humid climate.

Several years ago, I bought a Tiffany in late August that was covered with blackspot. It completely defoliated after it was planted, then replaced all its leaves in six weeks. No treatment except a sulfur dusting before it defoliated. It is now the healthiest HT I have, about 7ft tall last year, which is really unusual for HT's in this area.

OTOH, the only bush that had a serious BS problem for me last season was a new Black Bacarra. Other posters have indicated it is a BS magnet, so I will watch it closely this year. The layout of my rose garden and BB's nearness to other plants that were watered with a sprinkler may have been the reason it got BS. It never defoliated, though.

DD has been an issue for me because the first one didn't root, and its replacement has struggled.

Gary

What is the product name for sulfur? Does it kill bees?

Sulfur doesn't affect any insect that I know of. The Safer RTU fungicide is sulfur. You can also buy dry "wettable" or "micronized" sulfur under a variety of names. It a nontoxic plant and human nutrient. Controls powdery mildew and mites very well, rust and blackspot somewhat. "Garden" or "flowers of" sulfur is a coarse powder used as a soil amendment, not for spraying/dusting. See the FAQ of the Organic Roses Forum.

MICHAEL SAID:
Double Delight is no worse than average for a hybrid tea and is easily kept clean by a normal fungicide regimen. There are probably only a handful of hybrid teas (if that many) that can be grown reasonably well without fungicide in a rainy climate.

PATRICIA 43: If I recall, Double Delight does not like to be sprayed for blackspot. It revolts with fungicides. The leaves become curled and she looks ugly. I spray it, nonetheless.

Blackspot in zone 4/5 is nowhere like blackspot in the South.

Henry, in 5 years in my garden blackspot takes care of the roses. Most hybrid teas are dead in less than that period of time but surely 5 years would do them in.

Yes, BS can be a real problem, BUT if you have a good spray program, follow it religiously, and apply the right material, you can be virtually BS free. Essentially, the choice is yours. Follow the plan and you'll be fine, but if you don't care, then forget it.

Patricia, it's Daconil (chlorothalonil) in particular that Double Delight is averse to. I've read that it also burns Knock Out badly, though I don't know why anybody would be spraying K O.

I spray my Double Delight with the Bayer Advance Disease stuff and I've never had any problems with it. Double Delight is no worse or better for me than any other rose for blackspot. The Bayer Advance Disease control does not have any insecticide and should have no effect on any insects including bees. I don't spray any insecticides because I do like my bees and want them to be happy so they'll pollinate all my fruit trees.

My DD did ok with Daconil, but I was always careful to spray in the early AM when the roses were still wet with dew. It does better with the Bayer Disease Control.

kinglemuelswife, as you said - "have noticed that some people treat BS, others don't."

But:

I suggest that you look at the zone of those that reply before deciding whether their experience could possibility be applicable to your conditions.

Okay, does anyone know for sure if Bayer Advance disease control will or will NOT kill bees?

I will not kill bees. Read the label.

Kate

Dublin bay. I looked at the Bayer Advanced product and it DOES kill insects. Is there a specific one that maybe my nursery doesn't carry that you are speaking of?

I am still confused about whether spraying fungicides (that don't contain insecticides) kill insects. How about products such as Compass, Mancozeb or Rose Pride? If it does affect the insects, is it only when the product is wet on the plant?

Now that I am thinking about it, it seems that if it killed insects it would SURELY kill thrips and Japanese beetles and when I have sprayed, those guys are still around in full force!

Lynn

Lynn, Join the party. I am confused as well

The link below is the product that I use. There is no insecticide in it, and the MSDS sheet only warns that it is toxic to aquatic invertebrates so you shouldn't spray it near water. And apparently you can spray it in the eyes of a rabbit and it won't hurt them. It is dangerous if you get too much of it but it looks like you'd have to ingest quite a bit.

Here is a link that might be useful: Bayer Advanced Disease Control

Bayer makes various combination products that contain two or three ingredients such as fungicide + insecticide + fertilizer or insecticide + miticide.

However, the "Rose and Flower Disease Control" contains only the fungicide tebuconazole. Generally, fungicides do not pose a major hazard to insects, and fungicide labels generally don't include cautions about bees.. However, research has shown synergistic effects between certain fungicides and insecticides, that fungicide exposure can make bees more susceptible to insecticides. So it might be well to avoid spraying much fungicide on flowers that are open enough for bees to enter.

I do not see that much bee interest in my rose blooms. They do like the rugosa, but I don't spray that.

I have sprayed fungicide regularly over the last 5 years and the resident Honey Bee population has increased greatly during that time. A few years back, I thought Honey Bees were completely gone. I am reasonably sure that my spraying is not affecting the bee population.

It is important to spray carefully.

If you have a severe blackspot problem use Manzate. It kills the bs spores. Spray every three days for three weeks. Then switch to a regular fungicide spray and you'll take care of blackspot. Of course clean up the fallen leaves as these are full of spores that will reinfect the plant

Thanks Mike...that clears it up