Real compost improve soil and plant health in it's self but is so basic it is often ignored. There are Trichoderma perparations ( a benefitial fungi found in compost) that have proven to help with blackspot on roses, at least a few brands to choose from (on is BINAB). There is a brand called Terra Biosa that sell some products based on fermented herbs and grains (if I remember correctly), that are suppose to change the microlife to improve plant health. Maybe it is possible to immitate this fermenting process in some sort of compost bin?

There are the organic Demeter methods and preparations that can be tested out, but it is a bit on the alternative side related to antroposophy. Some of them come off as completely absurd, but oddly enought they work.

Amberroses, Do you attempt to keep the bad leaves picked up from the ground? I have been trying to just pick them off the plants and keep them off of the ground but now it looks like a huge task with over 50 roses, most of them badly black spotted.

In my no-spray garden setting I've found that organic fertilizers build the soil to create and environment where the roses thrive, even with blackpsot present in the garden.

The roses drop their leaves; however, they grow new leaves and bloom and grow well.

Serenade works fairly well and you can get that at Walmart. There's also Green Cure, which you can only get on line as far as I know, that works pretty well too. Other than those two you just have to learn to live with the spots if you don't want to have to use the big chemical guns.

Be sure soil is moist before spraying. Spray in the cool of the morning. It's probably OK if temperatures later rise to the lower or maybe mid- 90s. Any burn damage would appear first as vague yellow-tan areas in the middle of the leaf blade. Do not overlap with anything oily--oil plus sulfur will burn badly.
Because it does wash off, you might need to spray twice a week during the rainy season.

I used it under very severe blackspot conditions, and it kept most of the leaves on typical hybrid teas. It worked almost as well as the Ortho fungicide. I don't know how well it would work in Florida with the frequent heavy rains.

A poster here used WP with some success for a few seasons.

Don't mix with sulfur or apply over sulfur. I tried this, and it burns foliage.

Lime sulfur and copper sulfate dormant sprays can reduce blackspot, and here at least, there's no bees out during dormant spray season. Don't know about Florida though, bees may be year round there.

Henry, don't you dare diss Ms. Chalker-Scott in front of me. She is a respected university professor and extension researcher. I'm sure she'd be happy to send you her sources if you asked. She tries to communicate with laypeople on their level, and citing sources to scientific technical journal requirements makes things inaccessible to the average gardener.

Be aware that any spreader-sticker you add to a fungicide, like Safer's or dish soap or hort oil, is going to kill beneficial insects.

So no I don't know any organic fungicides that work without having negative consequences. Sorry.

H.Kuska reply. I was pointing out a FACT about a cited article. In your reply you acknowledge that what I stated is correct about that article

---------------------------------------------------
Perhaps you will be interested in what Ms. Chalker-Scott has stated (again without references) about:
"The Myth of Wandering Weedkiller" "Glyphosate will move through root-grafts and kill non-target plants"

-------------------------------------------
Please note the following undocumented statement:
"Do herbicides move through these networks? There are only a few studies that have addressed this
question, but fortunately each relied on evidence from hundreds or thousands of treated stems or trees.
The first study was conducted several decades ago using sodium arsenate to prevent regrowth of aspen
(Populus) and various oak (Quercus) species. Several hundred adjacent trees were studied for damage
from root translocation of the poison, but no symptoms of herbicide poisoning were observed. More
recently, researchers applied glyphosate, imazapyr, or triclopyr to control regrowth of cut stumps of ash
(Fraxinus), sycamore (Platanus) and birch (Betula). Again, no evidence was found to suggest root
translocation of any of the herbicides � applied to thousands of cut stems - to nearby untreated trees."

"Why do disease vectors move through root grafts, but herbicides don�t? Pathogens, like those fungi
mentioned earlier, require new hosts for their survival. As living organisms, they can evolve biochemical
pathways that allow them to overcome natural plant barriers and attack fresh hosts. Herbicides, on the
other hand, are not living organisms and do not change their chemical structure."

--------------------------------------
Compare the above to the following 1960 scientific study:
"A 30-year Pinus strobus plantation at a spacing of 6 X 6 ft. in the Mannabesic Experimental Forest, Maine, was chemically thinned with NH4 sulphamate in 1956, and examined in 1958. Of the untreated trees (80 out of 151) on sample plots, 43% were dead. Excavations of root systems indicated that death had been caused by poison translocated through natural root-grafts. [Cf.FA 18 No. 4109; 21 No. 1559]. KEYWORDS: Pinus strobus herbicides transfer via root grafts \ Pinus strobus rootgrafts, natural \ protection \ forests \ Roots, adventitious grafts \ Thinnings \ poisoning \ herbicides \ Arnmate \ herbicides \ plant growth regulators \ 2, 4-D \ 2, 4, 5-T \ herbicides \ translocation through root grafts"

http://www.cabdirect.org/abstracts/19606604544.html

--------------------------

Even dye has been experimentally shown to pass through root graphs of trees.

"Acid fuchsia dye, introduced through the tops of 10 freshly cut pine stumps, was observed to enter the sapwood of the stumps and to move, through natural root grafts, to nearby intact trees. From 7 of the 10 treated stumps, dye moved into 13 adjacent receptor trees through 31 major roots."

http://www.jstor.org/stable/1931939?seq=9
----------------------------

http://www.national-toxic-encephalopathy-foundation.org/fungicide.pdf

Do not confuse elemental or plain sulfur (which I recommend above and which is very safe) with lime sulfur, a toxic compound.

Also, while whole neem oil (such as Triact) could be toxic to bees, the commonly available neem oils ("water extract of neem" such as Rose Defense) have had the insecticidal fraction (azadiractin) removed, and these are probably no more toxic than canola oil.

Competing references are important for scientists to debate, but this is not the forum for dueling references...and it's not my field of expertise so I tend to follow Chalker-Scott.

"Many woody plants are directly connected to neighboring plants of the same species and any herbicide treatment applied to them can be translocated to other individuals sharing that common root system. Suckers produced by roots of an adjacent tree are an example of a shared root system. Cutting and treating these sprouts with an herbicide can result in translocation of the active ingredient to the common root system and may ultimately kill non-target trees. In some cases, trees of the same species growing in a given area may have a common root system as a result of root grafting. Never use herbicides to treat sprouts coming off a root system of a tree that you want to keep or on plants that may be sharing a common root system. Sucker producing tree species include: tree of heaven, honey locust, black locust, hackberry, western soapberry, cottonwood, aspen, poplar, willow, box elder, and others."

Please note: "This information has been reviewed by university faculty."

This article was produced in 2006.

http://arizona.openrepository.com/arizona/bitstream/10150/144792/1/az1 401-2006.pdf

-------------------------------------
Another recent (2008) reference:

http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74142.html

"Regrowth from cut stumps can be sprayed when leaves fully expand. Cut stump application of glyphosate can sometimes injure nontargeted plants of the same species in close proximity to the treated plant. This occurs via herbicide translocation through root grafts. This type of root grafting damage depends on the species. Rarely, if ever, does root grafting occur between plants of different species."

http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74142.html

----------------------------------------

Kaligreen and Remedy are two brands of potassium bicarbonate, similar to Armicarb in Henry's link. Potassium bicarbonate is very effective against powdery mildew.

Actinovate *seems* to work on blackspot. It is rather expensive and inconvenient, but worth it for me so far.

Any way I use it for black spot first and any other second and it works extremely well for me, although I soak, using a five gallon pail, the area around the rose(I do not use five gallons per rose). I do not just spray the rose.
It also stopped the leaf-spot in my strawberries dead in its tracks.

H.Kuska comment: I cited 2 research papers in this thread one studied roses in Mississippi and the other studied roses in Tennessee.

Also please remember heat turns "off" blackspot. "A temperature of 64�F is optimal for black spot development, but conidia germination still occurs from 59 to 81�F"

The above quote is from following Florida link.

Please note that they apparently feel that some of the organic type treatments are worth recommending to Floridians.

Most molds/fungi do not require light to grow. They require food, moisture and just the right of warmth/heat temperature to grow.

I doubt that fungicides have any effect on thrips or thrip predators. When I stopped using the systematic insecticide (the Bayer drench) I started having thrip problems.

There is a thrip remedy that doesn't involve spraying: buy blue plastic drinking cups, paint the insides with STP oil treatment and put those upside down on stakes in your garden. I bought the stuff but didn't try it. Some people say it works.

I clean up the deadheaded material, but I am remiss regarding infected leaves that have fallen. There are a few things that I just won't do, and this is one of them. I'd have to quit my day job to pick up all the leaves. Between the limbs blowing out of the 15 trees around us, the dog digging holes, and incessant watering, I'm outside all day anyway on days off. The leaf-gathering chore is one that I pass on.

Yes, it probably would help to clean up the ground around the roses, but they are planted fairly close together and the grafts are mostly below ground. There just isn't much space under each rose for maneuvering, and the biggest, gnarliest thorns are on the basal canes. I've already been stabbed enough this year when applying fertilizer. (It's supposed to be blood meal, not actual BLOOD.)

Untreated, the roses can look pretty shabby. With a light spraying schedule and a devil-may-care attitude on leaf drop, they're about 80% clean. Some things you just can't prevent. I know we're supposed to NOT typically water from overhead, but water does fall from the sky here periodically. Less this year than normal, but it happens.

Also the leaves will have released lots of spores before they dropped. Picking off the green leaves with spots could help slow the spread somewhat. This is easier than picking up fallen leaves anyway. I don't pick up fallen leaves.

However, the biggest contribution I make to all of this is that I plant only disease-resistant roses, and in fact, prefer the highly disease-resistant ones. I do have a few left over from the good ol' days when no one worried about spraying for BS (couple Double Delights, for instance, and Mrs. John Laing turned out to be a bit more receptive to BS than I anticipated) and I've loved them for years now, so I won't spade them. However, my favorite rose of all time is Peace and I refuse to grow it--it is a disease-magnet and I just won't put up with it as a result, no matter how beautiful it is. While there is only one Peace rose out there, there are many other beautiful roses out there that are also very disease-resistant--that's my kind of rose--the ones I never (or very rarely at most) have to spray for BS.

Here's one that has never exhibited even one blackspot and therefore has never been sprayed--Lady of Shalott. I think this highly disease-resistant Austin is gorgeous, don't you?

Works for me in Kansas Zone 6. Can't say about other areas, but I'd think these practices would work, or at least help, in a lot of areas.

In other words, quit looking for the magic (organic) cure. There is none--except for some good judgment and careful choices.

Kate

Even with the "except" I feel that it is too broad of a statement. Please see the link below for a more optimistic statement.

"4.As diseases and severity vary with location, you will have to experiment to find the most effective combination. With all these options, there is no longer any need to use toxic sprays, especially when resistant species and good cultural practices can help prevent the problem in the first place."

Or did you not bother to read past my first paragraph? Oh, I guess that was why you didn't notice my comments about planting disease-resistant roses -- the good judgment thing--or didn't you realize that is what I was talking about?

My goal is to MINIMIZE the use of fungicides--to use as little as possible to handle BS. Your goal is to completely ELIMINATE the use of fungicides and let BS take over. Since I have eliminated the use of fungicides on over half the roses in my garden, and only spray the others a couple times in the Spring and Fall, I fail to see why you think I need to be scolded by you. The good judgment I was referring to is pretty much the same good judgment you were referring to.

Yes, I'm ticked off.

Kate

Kate, I now have at least 10 roses that I don't spray. They never show any sign of BS so I don't bother. But most of mine are lost causes.

I am adressing: "are there organic methods that work?" Please note that the title of this thread is: "Organic fungicide that works". I presented links to 2 different reviewed published scientific papers on the subject. I personally conclude from reading them that there are organic methods that work under the conditions that the experiments were carried out under to my satisfaction (of course a rose shower who demands perfection may come to a different conclusion). I then presented a Florida University link with their view on the subject.

-------------------------
Your statement: "Your goal is to completely ELIMINATE the use of fungicides and let BS take over."

H. Kuska comment: I cannot understand how you drew that conclusion ("let BS take over") from either the Brooklyn Botanical Gardens article quote that I cited nor from their full article that I linked to (nor from my earlier posts in this thread).

#1: many rose growers have serious BS problems in their gardens, despite their good garden/rose-growing practices. If they go fungicide-free, there is only one possible outcome: roses devastated by BS. Your advice to them is a guarantee that their roses will suffer serious harm from BS.

#2: My post (which you failed to note) was NOT about those articles. It was about the new group of posters every year who come to this forum asking about the baking soda cure or proclaiming its virtues and wondering why those of us who have been growing roses for years are so ignorant that we don't realize we could go 100% organic and just sprinkle a bit of baking soda around--and all BS problems would disappear. Variation on this was the new poster who put manure around her roses and proclaimed the manure kept her roses free of BS and us ignorant ones ought to go organic and just spread around the manure instead. The same questions/assertions get made every year by some newcomers who visited an organic forum and think banana peels or coffee grounds or some such quick fix that is organic in nature is the obvious answer to any rose-growing problems. Strange how we do not hear from them in subsequent years about the tried and true organic methods of curing BS--or if we do, they confess that none of those methods worked after all. It was those kinds of so-called organic cures that I was referring to.

Now if you want to believe that the Cornell baking soda formula supercedes chemical fungicides, you just go ahead and see how well your roses resist BS. In the meantime, I will engage in practices (such as buying disease-resistant roses) that CUT DOWN ON THE NEED FOR SPRAYING--which was the point of my previous post. And I don't mean, cut down on spraying by learning to tolerate ugly BS-ridden roses. I mean, buying roses that don't get BS or only get it a little bit once in a while--that is how you can cut down on the need to spray. But until a whole new generation of disease-proof roses are created, I honestly don't see how fungicide spraying can be completely eliminated. It can only be cut down on by exercising good judgment and wise choices --such as, in searching for and growing only the roses that rarely get BS and therefore rarely need any remedial action.

Buford, I know what you mean. I had to do some long hours of searching to find roses that rarely or never needed spraying, and like I admitted, I still have a few that are much less disease-resistant than I want, but I do love those roses, so ......... Sigh!

Kate

Concerning your point #2. Yes, I did not comment about some/many parts of your post because I did not have a problem with those parts. I commented on "In other words, quit looking for the magic (organic) cure. There is none--except for some good judgment and careful choices."

You did not say some organic methods do not work under some conditions. You said: "there is none-- except....".

How can you say none when I posted reviewed scientific papers that say there are?

---------------------------------
The following statement was made: "I honestly don't see how fungicide spraying can be completely eliminated."

H.Kuska comment: I feel that would make an interesting thread to many new readers and I could (and have in the past) contribute some literature on that point. This thread is about using organic fungicides. I assume that by saying "organic" most readers are assuming the intent is "non-toxic". This is why I posted the Brooklyn Botanical Gardens quote and link.

Reve d'Or - I've NEVER seen blackspot or any fungal disease on it.

Crepescule

Roseberry Blanket (a great low growing carpet rose, better than a KO, IMO. I now have one that is sporting a white color and I'm going to try to propagate it.

St Patrick (yellow HT) gets some boitritus, but not BS.

Sophie's Rose (Austin) gets some PM, but not BS

Teasing Georgia (Austin) gets some BS, but does not defoliate.

Teas, most of them do very well. Mine had a small BS outbreak early this spring because the weather was so weird. Actually it may have been anthracnose, but they've been fine since then.

It depends on whether you want to get rid of the black spot or just let it have its way, there is no real inbetween.

If the bs is on the cane the fungicides with kill it. If you do not get rid of the leaves, as best as possible, then any efforts to get rid of bs are a waste of time.

To use such leaves as mulch is just plain silly.

I soak, my bushs and the ground around it, I do not piddle around with just spraying, with Serenade. The black spot goes away.
I do make a special effort spring and fall, whether or not I had, had, bs the year before, when the rose has no leaves to drench the canes.
But I do use a wet-dry vac. to suck up the leaves around the roses, especially late in the year.

If one wants the choice of roses one grows to be controlled by black spot then get the supposedly resistant ones, but if one wants to grow in one's garden, what ever roses the one wants, then make an effort to defeat the black spot and ignore the nay sayers that make excuses for not being able to control black spot.

I have taken to soaking my new roses in Serenade as roses I got from supposedly top rank nurseries have been the main reason I have had re-infections.

Teka- if you want to beat it you can, and don't let any who do not want to make the effort to defeat it convince you other wise.

Sadly up here we have a large public garden with roses but it is run by volunteers, and they have the ultimate way to get rid of the black spot that slowly infests the garden every so many years.
Rip the old ones out and put new roses and new soil in.
Not the best method.

On the right side there are other videos that sound interesting.