Sharon,

Take a look at Serenade. You apply it at weekly intervals unless it rains before the next scheduled spray. If this occurs, a spray after the rain is over is prescribed. Then back to your weekly spray counting from the new spray session date. You will have to spray both sides of the leaves.

Last year my niece, new to roses, was set up by me with Serenade and a good sprayer to combat her BS in her organic garden. Of course, being new to roses, not taking black spot seriously, and she foolishly thinking, "black spot happens to other people's roses, mine will not be effected, " resulted in no spraying being done. Disaster hit big time. Time will tell if history repeats itself this year.

I said all this to let you know I researched organic black spot control pretty deeply last year for my niece's sake. I found that Serenade appeared to be the most likely control to succeed. I have no personal experience with it. The Bayer fungicide is my conventional BS control choice.

I shy away from Neem for black spot because of the greater possibility of damaging the roses' foliage. The only location in which I can grow my roses is not the best for roses....hot, full sun with excessive, intense heat radiated from adjacent concrete and asphalt surfaces and brick buildings. My summer garden is like a hot desert, just very humid. My winter conditions are just as brutal, but in reverse. Only tough roses make it here.

Moses

Maybe organic rose forum have more tips.......I have used horticulture oil mixed with baking soda and water before, but I can’t spray it when the temp goes over 75F.

Serenade did nothing for BS here...BUT we get alot of rain so it was always getting washed off... :-/ Same deal with all organic sprays here... I ended up just planting roses that do well without sprays... (years of trial and error thats for sure...lol...)

Maybe in a different drier climate Serenade or something else organic might work better...??? I do not really know...?

A old time rose grower told me years ago that if something actually works many many people will be using it... If not, then you know it probably does not work that well...lol

I thought neem was moderately effective, but no comparison to my rotation of mancozeb/honor guard with daconil/Bayer disease control, lol.

Serenade sure sounded good in the literature, but it had no effect on blackspot for me.

Jim- I generally buy only disease resistant and winter hardy roses but I had St. Cecilia in the past and she was a workhorse, almost in continual bloom. Her flowers are stunning and her scent is phenomenal.

Thanks all. A couple of forum members get no black spot on their St. Cecilia. Maybe I'll be lucky this time around :-)

Sharon

Please let us know how St. Cecilia does for you this year enchantedrosez5bma.....Best of luck!

thanks Jim. I will.

sharon

Oh yes GreenCure. I used it for a couple years when I had about 350 roses at the time. It worked very well. It’s not cheap if you have a lot of roses.

I've used greencure for PM with success... But it did not stop BS here...Yes used to much it can cause leaf damage....

I used it 7-8 years ago when it just came out selling $9.99, now it's $17.99! I used it on 250 KOs and Carpet roses, and about 100 other roses back then. Could it be different roses taking it differently?

GreenCure is essentially potassium bicarbonate. You can get the active ingredient much more cheaply if you search for online brewer and winemaker supply stores. Here, it will kill mildew, but not blackspot. Last year I started too late to be able to say if it prevents blackspot if used before symptoms appear and repeated regularly, but I'm hoping to get started trying it regularly this year. If you use a hose-end sprayer, it's better to dilute it 50% with hot water in the sprayer so it mixes better, then applying at double strength. A little Dr. Bronner's Castile Soap (peppermint and lavender supposedly dissuade insect pests by making the foliage taste bad) will help it stick if it's too hot to add oil to the mix as well.

:-)

~Christopher

Thanks Chris! Just ordered 6lbs! :-)

Thanks Christopher. I don't have much problem with black spot since I have mostly Kordes roses but my Griffith Buck Folksinger black spots as does DA St. Cecilia. But she's just too luscious to pass up.

Summer- where did you buy the potassium bicarbonate? Thanks.

sharon

I ordered it from Label Peeler.

Chris,

Where did you get all your knowledge? I would say you have a PhD in Roseology! Thanks for sharing your wisdom!

Have you used Serenade for BS?Were made

Moses

Christopher, do you use anything for black spot? If so what works for you?

sharon

Chris, did you change your mind about FL?

Summersrhythm,

What is the measure per gallon/water of the over the counter potassium bicarbonate you are using rather than using GreenCure? Are they identical in ingredients, as in does GreenCure have other necessary ingredients in it to make its potassium bicarbonate work/work better? Thanks for your input.

Moses

It should be the same as GreenCure. It’s 1-2 tablespoon per gallon of water.

I also put some natural soap in mine and found it works amazingly well. I'm actually really surprised and hopeful that I can get in front of it this year. I used dormant oil February and I think that helped also. Paul Zimmerman uses a lime sulfur spray that he leaves on for 15 minutes and then washes off but I haven't been able to find that mixture easily. I did use just sulfur prior to the potassium bicarbonatemixture and it also seemed to work. However, when used it last year it wasn't enough after the blackspot got hold.

Oh I forgot about sulfur, I used to use it. I bought a 40 lb bag of sulfur, still have a lot left. I used sulfur with soap mixed with water.

......and MichaelG has mentioned years ago there were wetable sulfur out there, much easier to mix with water. What happened to MichaelG? Anyone knows?

Oh yes. That's how I use it wettable. It's micronized I think that's sold in the big box stores. The Cincinnati Rose Society suggest mixing it with some vinegar first to help with solubility also so I have done that as well. I suppose that also helps with the pH.

Ah, Label Peeler! That's where I got mine. I forgot the name, and after my previous computer crashed, I couldn't access my old files. Thanks for finding it.

As to how I learn this stuff, I just do a lot of googling. When someone mentions a product that catches my eye, I look it up, and check active ingredients. I remembered that bit about GreenCure because it prompted me to buy the active ingredient by itself.

So, if you plan to use 2 tablespoons potassium bicarbonate per gallon of water, I'd recommend putting half potassium bicarbonate and half hot water (in that order) in the mixer, and setting the dial to 4 tablespoons per gallon. That allows for better dissolving of the powder. You double the strength at the dial because it's half-strength with the hot water in the canister.

If you're adding 1 tablespoon per gallon of the soap, then you have to do a little more math. You'll want to figure out the volume of the hose-end sprayer's canister, fill one third with potassium bicarbonate, one half with hot water, and one sixth with soap -- in that order, so as to avoid the soap foaming up, and making a mess with the powder. It's also easier to do the soap last because you're just squirting it from the bottle until you reach the fill line. Learn from my mistakes -- haha! Then you set the dial to 6 tablespoons per gallon. How to get that? 2 tablespoons potassium bicarbonate per gallon of water plus 1 tablespoon soap per gallon of water equals 3 tablespoons of them together per gallon of water. That also means that, of the mix, 2/3 is potassium bicarbonate, and 1/3 is soap. But that's half of the container, the other half being hot water, so you half them as well -- 1/3 of the container with potassium bicarbonate, 1/2 with hot water, and 1/6 with soap. Then, since it's diluted to half strength in the canister with hot water, you'll have to double the strength on the dial to get the same dosage coming out of the sprayer.

If you couldn't follow along, no worries....just trust me that the math works out, and you'll end up with a spray that's 2 tablespoons potassium bicarbonate and 1 tablespoon soap per gallon of water hitting your roses' foliage.

:-)

~Christopher

Christopher thanks for all the info. What kind of sprayer do you use? My little sprayer doesn't adjust the dose. Do you spray all of your roses or just the disease prone ones? I try to buy disease resistant when possible but sometimes you just have to have a certain rose even if she's a bit of a prima donna.

sharon

I don't remember the brand. I just looked at my local Home Depot for an adjustable hose-end sprayer and found one. It has a canister that screws onto the hose attachment, which has a dial for setting the mixing ratio. I put what I want in the spray into the canister, set the dial, and spray everything. Last year, I didn't get started until after some blackspot showed up, so I'm unable to say if this mix is effective here at preventing it, but it did kill existing mildew, and not only on roses. A few other plants got it late in the season, and this cleared it up on them as well.

This sprayer is also what I use for any fertilizer during the growing season. Early on, I put down granular organic fertilizer (Espoma Garden Tone), then cover it with fresh mulch. During the growing season, I can't see much of the ground anymore, so I use a fish/seaweed mix in the sprayer once or twice a month, if I remember to do so. At this point, there's already a lot of good stuff in my soil, so the plants probably don't even need it. But it's something that feels good for me, and if nothing else, it helps break down last year's mulch layer beneath the fresh layer.

:-)

~Christopher

Thanks Christopher. I'll need to buy one of these. I'm saving all your helpful info for future reference.

Sharon

Thanks for asking, Sharon. I have a hose-end sprayer somewhere, but should just buy a new one. However, iIve been VERY happy with the 2gal mosquito sprayer I bought last year. I attached an old strap to it to put over my shoulder and find it very convenient to use..

When using a hose end sprayer, I recommend connecting after an anti syphon device.

https://www.google.com/search?num=100&newwindow=1&source=hp&ei=RgT_WqbDN4rgjwTg15GAAw&q=garden+hose+anti+syphon+device.+&oq=garden+hose+anti+syphon+device.+&gs_l=psy-ab.12...4800.15877.0.18786.15.14.0.0.0.0.181.1467.4j9.14.0....0...1.1j2.64.psy-ab..1.4.474.6..35i39k1j0i22i30k1j0i13i30k1j0i13i5i30k1.122.W3XdWA2k0lQ

Thank you for that reminder!!!! Great link!

@enchantedrosez5bma hi there!!! I’m so curious to learn if your new Cecilia did better with black spot? I finally found her and I’m hoping to get away with just using sulfur or copper spray.

Ahhhh I can’t wait to smell her :)

Sarena, I put Milorganite fertilizer around my St. Cecilia here and had no blackspot.

@Sheila z8a Rogue Valley OR Oooooo that’s really interesting! Thank you I’ll write it down. A slow release nitrogen one huh? I’ve been hearing about one called Great Big Roses that utilizes humic acid and kelp meal. It is also meant to make roses healthier and prevent black spot. I want to be a no sprayer so bad. Fingers crossed.