It's no secret what conditions cause blackspot. It's also no secret certain types of roses (e.g., HT) are more susceptible to it than others. Last year I sprayed with Bayer Advanced on a regular schedule and despite my best efforts most of my roses were naked by August. This year I switched to Banner Max. Here it is August 2 and not one rose, and I grow mostly HT, of my 75+ have blackspot -- including 5 that only get 4 or so hours of sun.

Now! I know there are those who insist on a no-spray garden and I'm jiggy with that. Unfortunately with the kind of roses I grow and my location I don't have a choice.

All my roses are in full basking sunlight from morning to sundown. Some are much more susceptible to blackspot than others. Some don't get it at all (my albas), others I have to make sure I spray (such as G. Jeckyl and Louise Odier).

This is the first time I have ever read here that Banner works better than Bayer (propiconazole better than tebuconazole). Hmmm... My experience is that Banner absolutely controls BS if used correctly on any rose under any conditions. I have never used Bayer so I can't compare but the research results for tebuconazole are compelling. This year I could not spray because of my broken ankle and people I hired to spray didn't show up because of the continual rain but I got spraying again in June and Banner has got the situation under control. The key is to immunize the rose so you have to start early before D. rosae has a chance to get started and its' symptom BS starts to appear. BS shows up long after D. rosae has done its' damage. Only when new foliage is clean and stays clean will you know you have won the battle.

my neighbor has roses that are in the sun all day. He uses bayer 3 in 1. In a week or so he will probably be taking all his leaves off. I couldn't garden here without bannermax. Donna

I'm one of those no sprayers. I SP'd four roses this year, that just couldn't seem to shake the blackspot. I only have a couple more that are iffy, and I'll give them another year. I have two climbers going up a pecan tree with plenty of shade. Never a touch of BS on either of them. In fact all of the ones I SP'd were in full sun. Real estate for happier roses.

I have roses in full sun that would be bare from black spot if I did not spray them and at the sametime I have roses in part shade (morning or afternoon) that do not get black spot. So IMO it depends on the rose.

Liz

I have not sprayed this year for blackspot.
But, I have been foilage feeding every 2 weeks with Drammatic K fish/kelp fertilizer.
All my neighbors have severe blackspot on there roses, I have not had any blackspot.
Did alittle research into my fertilizer i'm using to foilage feed and came up with this from the company.

http://www.dramm.com/html/main.isx?sub=72

As a general rule, I tend to believe that more sun equals less BS, but I'm sure there are many exceptions to that rule. However, I have grown certain roses in gardens that featured some dappled and/or light shade and the same roses in gardens open to the sun for at least 6 hrs. Based on those roses, I can say that the lightly shaded roses had more disease problems--not unmanageable, but requiring more work (spraying) than those in lots of sunshine.

Of course, my personal experience may not be valid for other cases, depending on the roses in question. Roses expecting to reside in my gardens must arrive with good disease-resistance credentials--or I don't let them in. As a result, I spray only a few times in the spring/early summer and again in the fall a couple times--with the fungicide Bayer Garden Disease Control (not that 2 in 1 or 3 in 1 or all in one crap, by the way).

Since I tour my gardens frequently (obsessive-compulsive!), I can usually spot the first couple black spots and whip out Bayer Disease Control right away. It does a good job. How it would work if I waited til the roses had lots of blackspot, I don't know--because I never wait that long.

My advantage here in KS is that it is so hot in July and August (most years) that not even blackspot can stand it, so I get a break from the weather--though it is usually too hot for ME also! LOL

Kate

Hi, Kate! me too I'm in KS and just like you! I feel it's too hot that blackspot croaks in our blasting direct sunlight (so long as it's direct sunlight...)

I'm doing a tally of those like JeffAurora and Veilchen (Maine and New Jersey)...those places get lots of rain, so in my opinion they are in prime BS climates so that the rain will defeat the sunshine...and that there's no way to be able to combat BS without synthetic fungicide intervention. Also the sun is northern and does not have the intensity to bake out blackspot (at least according to my proposed "theory").

Now rosenpots, it's time for me to get your tally since Virginia will have more prime sunlight... You say you spray some of your roses that keep getting BS in full sun...Do those roses get both afternoon and morning sun like Veilchen's... So on the ones that don't get BS in part shade do you not spray them at all? Out of the ones that only get afternoon sun, do they get more BS than the ones that just get morning sun. I think this is another key detail that would be interesting to compare. My backyard roses get just morning Eastern sun--in the afternoon the house casts a large shadow...I have two prime BS roses, Mr. Lincoln and Aromatherapy that do not! get any BS. All my backyard and back patio roses are so pristine and vigorous but I credit it to Midwestern blazing sun intensity. I will be interested in finding out whether Arizona, Nevada and Southern California get no BS.

As Dublinbay points out Kansas sun is a true roaster.... I use organics and am an obsessive freak sprayer just in my completely shaded front yard and a lazy once a week sprayer in the backyard...The front yard where it's all shade is pretty much hopeless, shame on me for planting roses (I thought originally it would get dappled sun especially come summer but I was sooo wrong, the shade is getting worse!) Horrors of horrors last year I didn't know I'd be growing roses, or else I would have observed the patterns of the sun. Their best light was actually in the spring...

Jim you forgot to mention that your neighbors' roses are in partial shade and that yours are in full sunlight...

o.k. any thoughts anyone about heat changing the striping of roses or sunlight changing the form and coloration of the rose as the seasons pass?

(Maine and New Jersey)...those places get lots of rain, so in my opinion they are in prime BS climates so that the rain will defeat the sunshine...

Rain is certainly a factor. However, excessive unrelenting humidity is the biggest contributor to blackspot here.

re: excessive unrelenting humidity......I agree, because I, too live in an area with unrelenting humidity BUT I also understand that it is the temperature range WITH the humidity that brings the BS. BS likes a certain temperature range - am I right?

It is extremely hot here (along with very high humidity) but we usually have a break from the BS in the summers and I am gradually understanding that the combination of extended periods of time (i.e. never ending summers) with the high temperatures (high 90's) keep the BS at bay. I sprayed about half my roses about 4 or 5 times in the Spring( around April) when BS hit hard but haven't sprayed since and it doesn't matter which variety of rose (HT's included) or whether they are in shade or sun, the foliage remains very full and lush.

It may have "helped" that this was also the driest summer ever, as far as rain is concerned.

I am seconding everything Kate, above, says!

I fully anticipate when the temperatures drop here, sometime later in the year, that the BS will come back.

Lynn

It is very commonplace for roses to change colors in the heat, and to also not last as long on the plant. There are always exceptions, but generally colors are not as deep, fade out more quickly, and blooms shatter faster when it is hot vs. when it is cool.

My rose idiosyncracy is that my roses in the ground tend to have no smell. My roses in my pots have great fragrance and do better in general.

Aphids seem to like soft leaves (obviously new leaves), but they like the leaves that are soft like Graham Thomas versus roses that have hard leaves like Aromatherapy. I guess it stands to reason! :)

Carol

Our roses get full sun, from early morning until early evening.
We have 2 different neighbors with roses and they get sun from mid-day through evening.
Both neighbors are having major trouble with blackspot on all there roses due to the rainy cooler weather conditions.
We have had no trouble with blackspot at all and I have never sprayed a fungicide on them this entire season.

What I was wondering is that I do foilage feed our roses every 2 weeks with Drammactic K fish/kelp fertilizer. This fish fertilizer has the fish oils in it, unlike other fish fertilizer products on the market.
Is it possible that our roses being in full sun and me using this fish product to foilage feed with is keeping blackspot at bay???
As we plant more and more roses over time and different types of roses I will keep foilage feeding with this fertilizer product to observe what happens.

When I first purchased the fish fertilizer I had a question on how much to use for roses as the directions were unclear, so, I wrote the Dramm Corp. for answers.
Here's the e-mail I got back from there company representive.

Good Afternoon James,

Thank you for purchasing Drammatic K fish fertilizer.

I would use the rate for flowers and vegetables. 1-2 ounces per gallon, weekly for every 20 square feet.

I also grow roses. This is my routine. Drammatic K is not a salt formulated fertilizer like Peter's or Miracle Grow. So root damage is not an issue. I use 2 ounces per gallon. I water my plants with 1/2 gallon per plant. I will increase the rate if the plants need it. Some rose varieties require more feed. They will let you know, small flowers, chlorosis in leaves, not enough blooms and small leaves are indicators of this. This is the strange part of watering and fertilizing. All rose directions will tell you not to get the foliage wet. I do the reverse. I water in the morning and I make sure I get the leaves wet with the fertilizer water. I tried this after many of my organic vegetable growers telling me that the oils in our fish retard Powdery mildew, Downy mildew and Botrytis. My roses seem to benefit also. Happy growing.

Tim Tetzlaff
Dramm Corporation

this is very interesting Jim; at first on their site I only saw the mention of fusurium fungus, but am glad you asked them more in-depth. I will have to give it a try next year.

Canadian rose, I too second your opinion about aphids; they seem to dislike leathery thick leaves...They completely avoid Aromatherapy, my PennyLane, Queen Elizabeth, Special Occasion and especially my stray miniature rose...They like Gemini and Mr. Lincoln's young leaves but not the mature ones.

Greenhaven I think I have to say my roses are actually the opposite of yours. They do not get light or fade in color. In fact they do the direct opposite...LOL! they turn neon! like super intense and saturated colors...Temps are from 85-97 degrees, but we haven't gone above 100 degrees yet so maybe I might see a change if it was like Arizona, but to me our heat and blazing sun intensifies the color...

Arizona, Nevada, anyone in the hot dry climates, no BS right?

Canadian rose like you I notice potted roses grow a little bit different. My observations are this:

1. potted baby bands bloom faster and more prolific! than potted young own-root roses.

2. potted young own-root roses bloom faster than young own root roses planted in the ground, but young own root roses planted in the ground bloom much! bigger.

3. young own root roses planted in the ground are the slowest to bloom compared to potted baby bands and potted young own root roses.

4. grafted roses bloom equally as fast whether they are in pots or in the ground.

We had 3 years of drought, weeks with little or no rain and I still had blackspot. In fact, it was worse because the plants were so stressed. It's mostly temperature sensitive and any humidity will allow it to survive.

I have notice the stripped/bi color thing in the heat, but I think it's just that the colors 'turn' or get deeper and mix together faster than in cooler weather.

Also, I have thrips in my very dark roses. They are just not as noticeable and don't seem to do as much damage.

hmmm, Buford. My guess is because you're in Georgia? Georgia and Alabama are supposed to be super, super muggy (humid) which blackspot absolutely loves, is this correct?

That is very interesting that the deep colors are making the stripes likewise dark and "disappearing". I never thought about that factor... So yours gets darker like mine in the heat? Maybe that's why our Kansas roses don't fade unlike Greenhaven's...You have humidity but we get the moisture of a few rains here and there.

For some reason the rose slugs don't seem to like my Lady Emma Hamilton