I wasn't the poster Sammy is referring to, but I have an opinion..for what it's worth....
I read an article about grapevines, about a study trying to figure out why old grapevines didn't get the diseases that young vines do. They explored genetics, culture, etc...but the conclusion that they came up with was that the vines developed a bacterial and fungal defense system of their own to fight off the diseases that attacked them over the years.
In my own experience with roses..(I don't spray)...is that they do seem to be able to fight off BS as they age. Many of my baby Buck roses are so covered that they defoliate, but in their second and third years there is a marked decrease in BS.I am not knocking the Buck's, I love them, just using them as an example because they consistently get a lot of BS as babies here). As Sammy said..some roses are just BS magnets all of their lives, but many do seem to overcome it.
I have also noticed that moving a rose, or adding a new rose to an established bed will kickstart BS again..maybe they are bringing in a new strain, or in the case of transplanting, maybe the rose is temporaily weaker, but it passes.I think it is better for the rose to let it fight it's own battles.
There is a poster(digger dave) that we haven't heard from in a long while?? but he sprays his foliage regularly with plain water, and he has very clean foliage.
I am just not convinced that chemicals are the best answer. Donna

I'm not the poster Sammy talks about, either, but I think there was an earlier post that discussed whether roses became BS resistant after about 5 years. Many posters thought so, some didn't.

My garden is no-spray, and I agree with "a healthy plant that starts with soil". At least, my experience backs that up. I am seeing some of my roses that have had considerable BS in the past not have as much. But, if a rose completely defoliates, I shovel prune them at that time. Just figure I can live without that heartache and can find a better rose for my garden.

This is a good topic to cover as BS affects so many of us, and I think more and more would like to go organic. And - don't laugh - but after getting over the shock of the urine post, I am seriously considering trying that. I'm wondering how to approach DH! :) Or, would the roses always need that? Should I just let them build up their own defenses?

Good topic, Sammy. Hopefully the poster you're referring to will chime in.

Donna, your post really reflects what my source has said.
It gives me new hope for my garden.

I have not heard Digger Dave talk about spraying with water, but I do that. In our heat I think that the water is good for the rose even if it may promote black spot.

Sammy

I know the poster- Been in that particular garden a few times as well. I have seen the living proof. I for one, am going to follow this advice in my own garden. Even though I have been a part of rose growing for more years than I care to mention, my own rose garden was just begun this part September. I have several "specimen" plants all over the place but this is my first true garden. I will NOT be spraying any chemicals at all. Come what may.

Trish

Paul Zimmerman is my mystery mentor.
I just don't like to mention a person's name without permission.

At this time of year as roses are slowing down, rose growing becomes rather discouraging. His message was a real boost to me, and has made me feel pretty good.

I hope it helps others of you who are struggling with "no spray" gardens.

Sammy

In my climate BS resistance does not depend on the plant age. In fact plants in their first year often get less BS here.
Sorry to contradict others, but my guess it depends on where you live and how bad is BS in your area. If I remember right, MichaelG who also lives in BS paradise has the same experience. Plants that stay reasonably healthy for a season start getting it really bad in following years.
Olga .

That's been my experience also. Sometimes new roses are pretty good for a year or two, and then show their 'true colors'. I don't believe I've ever had a rose improve in blackspot resistance as it became more mature.

Sammy...I saw on another forum, pics of digger dave's roses and his spray program, with water..really impressed me.
I believe you are misunderstanding the part about roses being sprayed with water "promoting" blackspot...if you spray early in the day, so the water has time to dry off of the foliage, it won't promote blackspot, if you spray late in the day, when water won't dry, and it sits all night..then watch out..you will be promoting blackspot!!
One other thing...blackspot has a very narrow ph range in which it can survive..that is why some formulas have vinegar, and other baking soda..one raises ph, the other lowers it..when in reality, all you need to do is use anything that will get the bs spores out of their "comfort zone"..and they will die. That is why powdered milk has been somewhat effective through the years for people. Plain water will knock the spores off of your foliage, but depending on where you live and what the ph of your water is, may also help kill them.
Great thread!! I hope to learn more about this problem that plagues us all! Donna

Does anyone use vinegar in a hose-end sprayer? If so, how much is the right mix? Also, for soil with a higher pH would spraying regularly with vinegar help to lower the pH? Would it hurt anything? Is regular white vinegar the right stuff?

Niels made an interesting statement in another post on unusual roses recently. He said his Serratipetala developed BS in his garden even though Chinas don't usually have a problem with it. He attributed this to Serratipetala needing a warmer zone and not being entirely happy (strong?) in the colder zone that he's in. Just a thought.

Sherry

I am not sure what I believe about black spot even if I have been growing roses for so many years.

Donna, you are correct about watering. I have always heard that we should water so that the water will dry before night. But I am not so sure that watering in the evening here is harmful. I am trying to clear my own head and separate myths from truths, and separate rules for modern roses from rules for older roses.

Another problem for me is that I leave for work at 7:00 in the morning, and return home at about 4:00. Often it is evening before I can water. When it is so hot, I try to think about the size of feeder roots compared to the size of leaves, and where the rose takes in more water. If I spray with the hose overhead at about 7:00 or 8:00, it may dry in our heat, and if it doesn't, the rose may need more water than protection from the black spot.

This fall my roses have gotten more disease than I can remember, but the leaves have not dropped. I don't know if they have black spot or cercospora (sp). I have not watered much, but we have had so much rain. I do know that we have had powdery mildew, and that is seldom a problem.

I did not think we could kill the black spot with anything except Manzate. I thought the chemicals that I won't use anymore would just prevent, but not kill.

I believe there is a strong connection between what you are saying about grapes, and what I want to know about roses.

Now, I need to think -- and get ready for school.

Sammy

It's very interesting information. In my garden setting, I find that as the roses mature they repeat bloom better, seem to "shrug off" blackspot: grow new leaves and blooms.

I do think that the quality of the soil will help the roses to grow well.

I haven't found that my selection of roses has narrowed down, I grow a wide range of roses.

Sammy, my roses develop blackspot problems when we have prolonged periods of overcast, misty/foggy days. The older varieties aren't so prone. I have much more disease problems with the newer varities, thus they are progressively being shovel pruned.

I have watered this year with overhead sprinklers and my roses have never looked better, little to no blackspot until the weather we have had lately, with few sunny days and lots of cool, foggy and damp. I turn the sprinklers on just whenever, no difference I can see.

I have reached the resolution when you have roses, there is just gonna be some fungal disease. Even if you are a major fumigator, there is likely going to be some level of fungus, good and bad, in your garden.

Sammy..here are a few articles......
Baking soda as a BS preventative...

http://www.puyallup.wsu.edu/~Linda%20Chalker-Scott/Horticultural%20Myths_files/Myths/magazine%20pdfs/Baking%20soda.pdf

This is very interesting..among other things, it says BS spores can overwinter in the stems of your roses..very good info on the life cycle of BS......
http://web.aces.uiuc.edu/vista/pdf_pubs/610.pdf

This is a cool article..about how drought stress makes plants produce more disease fighting chemicals...
http://scialert.net/pdfs/biotech/2008/273-279.pdf

sherrycola...here is a gw thread about using vinegar
http://forums.gardenweb.com/forums/load/rosesorg/msg0117185530492.html

other recipes...
http://forums.gardenweb.com/forums/load/rosesorg/msg0117185530492.html

The things that I have learned are that BS spores are very prolific and can overwinter in the stems, as well as mulch or fallen leaves..they can be brought in by insects, wind, new plants,or humans...so prevention has to be ongoing, unless the plant has an immune response or can be induced to create an immune response. With so many strains of BS, it seems to me that it could take years for a plant to develop an effective immune response of it's own, and that would be in a closed garden with no new additions, (to bring in a new strain), and no wind or insects !!
I guess the optimum plan of attack would be selecting BS resistant varieties, combined with spraying **just about anything*** , and good sanitation. Donna

Sammy..I did read a couple of articles that said if you have dry, windy nights,with low humidity, that it will dry your foliage, so maybe evening watering won't hurt where you are...as with everything..it's all about experimenting. I also think that I read that a rose leaf needs 7 hours of being wet or a combo of hours and very high humidity for a BS spore to grow.Maybe someone will correct me on that point...Donna

Thank you for your posts. The revelation that has impressed me the most is that the leaf has the ability the fight off disease with the good fungus that is naturally on its leaf.

I am still twirling that good new around in my head as I think about watering, soil, and how to handle the canes of older roses.

Donna, I just got home not too long ago, and have not had time to click on your links, but I do appreciate your sending them.

I wish I could find the scientist who said that the life of the fungal diseases has been highly exaggerated. It was posted here within the past year, but I don't remember who said it. He said the fungus dies shortly after hitting the ground and does not jump around. He explained that we are wasting our time picking out leaves and we should just dig them into the ground.

Must go now. Does anyone remember that post?

Sammy

About 15 years ago I bought an Abraham Darby and what I guess is a modern rose, Las Vegas. The Las Vegas was not planted in the best place (not enough sun), and both roses were just covered with blackspot every year. Abe performed quite well, lots of flowers, but would get about one or two roses from Las Vegas, which just sort of languished at about 2 feet tall.

After getting really interested and researching, and not knowing any better just put everything, Epsom Salt, Alfalfa pellets and corn meal, along with the coca cola mixture, I just dumped it all on there. Didn't seem to do much the first year, but this year there is literally no blackspot on the Las Vegas, lots of blooms (including a fall bloom!) and growth of about 1 foot. Abe looks good too, a little blackspot, but can live with that considering the absolutely beautiful flowers.

Don't know which of these, if any, amendments worked, but in my case, I didn't kill them, and am quite happy with the outcome!

Um, how about just growing disease resistant roses? What might seem to be resistant one year, may turn out not to be in subsequent years. Easier to just grow those that are known to be relatively resistant, and/or to tolerate some low level (

My Soleil d'Or, had no black spot for first two years followed by 4 years of devastating black spot, this summer none (delayed cold spring and hot dry summer) ... I believe in climate / weather vs rose genes ... not in shaking it off.

When I first started my rose garden, I had no blackspot, none at all. I started to think that my climate was perfect for the roses I was growing, all that soil improvement had paid off, etc. But by year 3 BS showed up with a vengeance and now I have to spray (Bayer) at least monthly or many of my roses will lose about 1/2 their foliage by fall.

My soil is enriched with loads of compost, aged manure, top dressed and mulched with leaf mold, more compost, more manure yearly, so I don't use any chemical fertilizers.

I grow a variety of roses but the majority are Austins. Some Austins fare better than others as far as BS. Some of my worst offenders are the OGRs. I have a tea rose in a container (needs to come into the garage for the winter) that has the worst BS of all. The only class that seems resistant in my garden (so far) are albas. But albas don't repeat. I have grown a couple Bucks and Canadian Explorers--if they didn't come down with BS they were infested with anthracnose.

I wish it were true that given good soil the roses would eventually fight off BS on their own, but in my experience they don't.

Sammy I remember the thing about not picking up leaves to prevent fungus. There was a study done(now I forget where) that found that the fungas dies when it hits the ground. I first read about it in a Vintage Newsletter.
I've thought about the idea of roses developing resistence to fungus as they get older. I guess all I can say is that isn't the case in my garden after many years of growing roses.

From the December 2008 Vintage Gardens newsletter:

"Dead rose foliage may be left on the ground to decompose and add to the soil. Only living green leaves will harbor disease, and these can be covered with mulch to start the process. DonâÂÂt waste the precious organic matter your roses shed each year"

I did try to pick up the dead leaves in my garden - once. It seemed to be an impossible task as the leaves were mixed with compost, mulch, and the leaves and needles falling from nearby trees.

Most of my roses have done well so far without spraying. I have shovel-pruned the worst offenders. It may have been unwise, but I added some teas and bourbons this year. (I have read that teas get more bs here).

We have always tried to garden organically, for example - resorting to roundup only for poison ivy and some extremely aggressive trumpet vine. But in the future, I may consider spraying a small percentage of my roses, the ones I am in love with that have no substitute.

Maureen

Here is a link that might be useful: Vintage Gardens newsletter

Sorry to be so late to jump in but my Sister was visiting.

Very interesting thread and to me it seems to point out a few things.

As a general rule it seems starting with disease resistant garden roses helps as does good soil etc. That has been my experience with roses in Los Angeles and now here in the upstate of South Carolina. My roses when not sprayed get less disease over time.

In my travels I have encountered other rose growers who suspect the same thing.

However we once again learn how regional rose growing is in the United States and what works for me does not work for others like Olga for example. And vice-a-versa.

If you are willing to try this I would suggest you do but it can take a few years to make the transition for your existing roses. I would definitely advise you speak to other rose growers in your area to learn which varieties do well in your region. And if in the end it doesn't work and you need some spraying that's okay too.

No fast hard rules. The best way to grow your roses is what works best for you.

Thanks for jumping in, Paul. This has been an interesting discussion, and I appreciate your having started it.

Sammy

The best thing you can do for blackspot resistance is to grow roses that are adapted to your climate. Then, provide them with good soil that is replenished with nutrients, and adequate water. Just like humans, they do best when kept strong nutitionally and environmentally. I consider sprays to be similar to putting someone on antibiotics...not something I want to do often, if at all. I'm a low maintenance kind of gardener anyway, (in survival of the fittest mode) so I don't spray. It's amazing what nice roses you can grow when you find the right ones.

Oh, and I do hose the foliage off at least a few times a week. I feel it works. I was told at a patio furniture store that if I hosed the dust off frequently, I would eliminate the food that mold needs to grow, and my furniture would stay clean looking. It works, and I definitely feel it works on plants too.

Sandy

I have been completely no spray until this year. We had a very damp spring and the bs hit like a tornado. Even my two very old, established roses were hit, where in the past they have remained untouched. So I sprayed about every three weeks. I don't want my roses to become spray dependent, but I felt they needed a little help fighting off the fungus this year. It's like taking antibiotics--I believe one should let one's own immune system build up it's resistance, but there are times when medication really helps. The Middle Path.

I don't feel it hurts at all to do some spraying when it is needed, especially if the rose might possibly be lost if it isn't done. I don't generally spray because that particular chore ruins MY enjoyment of growing roses, and I found some roses became too dependant on it. Some people do not mind doing it, and most serious gardeners are very responsible about it.

When I run into that particular situation with a rose or two I usually pick up a spray bottle of Bayer that's already mixed up, and treat the rose a couple of times. Sometimes that is all it takes to help it through a rough patch.

Sandy

That's a nice analogy to antibiotics. You only take them if you can treat a cold or flu without them and then stop taking them when you are better.

Completely agree about spraying if you have to - particularly if it means you might lose the rose. Downy mildew is a good example of something you have to spray for. Nothing wrong with chemicals when other methods don't work and then backing off when you have whatever it is you are treating under control.

This is very much my approach to gardening. It started of as an interest in bio-dynamic gardening with lots of unusual remedies. One of the most important things are compost and how well it is composted. I have not managed to grow my garden all bio-dynamic, and some fertilizers I use have not been certifiably organic, but they are natural.

A very interesting branch of this sort of approach Sammy talks about is use of beneficial micro-organisms like trichoderma and mycorrhizae. It helps roses becomming more restistant to blackspot, and growing roots. I am convinced that seaweed and kelp help strengthening roses too. This type of gardening can really show results after a few seasons.

Hi -- Here in west-central coastal Fla., I have found that spraying for BS and Thrips is the best solution, otherwise a plant can be de-foliated.... I have mostly grafted on Fort. Hybrid Teas , climbers, Polyanthas, etc. a variety.... and find the best thing to prevent problems is spraying when I see a problem, maybe once a month, every other week, whatever.... I like Bayer 3-in-1 also Rose Pride, and alternate... but try and keep the plant healthy with lots of organic as well as granular fert. also Miracle-Gro for Roses...... sally

Excellent thread, ya'll! Thanks to all who have contributed. I'm SO hopeful that all my homework as to getting the most disease resistant roses will help with this problem, but know that a good location, good well nourished soil, proper watering and good drainage will do their part to keep diseases at bay, too. I've over ordered for Spring, as I know that I'll be culling those that don't do well here. I hope that the hybridizers will keep working to keep disease resistance as one of the top priorities in their breeding programs. They need to remember that roses will be history if people don't buy them because they are too hard to keep decent looking. Around this area, crape myrtles bloom all summer long, and are just gorgeous and healthy looking with NO extra care or work. When you see one of those with a puny, defoliated rose next to it...well, you get the picture! Also, there are so many roses today with very little or basically no fragrance. It's that incredible fragrance that makes it worthwhile to deal with the rose problems that can emerge. There's just nothing like stuffing your nose into a big, fat, fluffy rose with fragrance that you'll remember forever! Crape myrtles don't have THAT attribute! Barb

I wish Ron was around and would contribute to this thread. I just remembered about his use of aerated compost tea. He sprays his thousands of roses with it, doesn't use chmeicals and swears by it.

I don't know Ron. Who is/was he?

Sammy

Ron has a funny handle that I can't quite remember properly, something like jartenderix. He is the owner of Garden Valley Ranch a nursery and cut flower(roses)bussiness in Petaluma California. A few years ago he attended a seminar on using aerated compost tea and decided to incorperate it into his gardening care. It involves some equipment that aerate the compost. The last time I spoke with him he was really excited about how this worked for the health and disease resistance of his roses. That was a while ago. I read an article(can't remember the name at all. Sorry) by a plant scientist who felt that the aerating made no difference and that compost shoveled or sprayed on was healthful to roses, with no comment as I remember about fungus. It would be good to Google this.

Sounds like there's a consensus going here, and I'm totally online with it. So here's my situation:

My neighborhood is a "gentrifying" Sixties subdivision, surrounded by developments of new McMansions. So, in addition to Mosquito spray trucks, we have toxin-drift from rich rednecks whose lawns are automatically and continually misted with poison (more, I suspect, from a desire to have every fancy feature than from fear of West Nile). To make matters worse, we're on top of an old Cotton field, and so the soil structure has been compromised by deep-plowing. Too, there is probably residue from Arsenic (to control Boll Weevil in the early Twentieth Century) and DDT. There may be residue from pre-1965 herbicides, too. And the ground is wet enough that Crayfish castles pop up nearly everywhere (at least there's SOMETHING aerating our soil).

Of course, around a 44yo. ranch house, there's also the usual residue of termite poisons, residual residential herbicides, lead paints, organochlorines from house-washing....

Do we have a chance in 'H-word place' (cussing is not allowed in Madison) of developing/cultivating healthy, microbe-rich soil here? Healthy enough to make Organic Rose Gardening possible?

Nothing is growing really well here: not one thing, except for 'Screening Bamboo' and Rosa Laevigata. I'd just let it slide, except that this is an intensely materialistic culture, and how one's home looks is pretty much the most important thing in the world. Right now, our scraggly plants are devaluing us as people.

Should I forget about Mother Nature and embrace 'Better Living Through Chemicals'? Or should I just scrap all the roses but Cherokee, and stick to Bamboo and Boxwood?

BTW, I suspect that the success of the 'Goldwater' dude, and the one who sprayed with plain water, is dependent upon temperatures over 90 degrees fahrenheit. That may be what prevents the moisture from encouraging Blackspot. And did the 'plain water' dude spray with chlorinated water?

Ooh! Can you move? You don't like those neighbors at all.

Is there a way that you can have someone from the city look at your property to find out exactly what the contamination is?

We have termite poison. I think everyone here does, and probably in Mississippi too. Many of us also have the other contaminates, but I have always presumed that they have been washed down through and out the soil over a period of so many years.

I don't have raised beds, but I put in 3 bags of store bought soil with every plant. Plants that we eat are in whiskey half barrels or metal pots that are that size.

You don't mention that you love to garden.
Why don't you hire a service to put in sod so your grass looks nice, and get someone to put in some nice plants that do not need to be sprayed?

I don't quite understand your last paragraph.

Sammy

I haven't sprayed my roses since early spring, 2009. They appear to be fine, even in this cold. I've observed that the OGRs and rugosas tend to be more disease resistant as they mature.

I'm going to experiment this coming season w/ no spray, except maybe water in the heat. I've also noticed that my organic roses are just as healthy, if not more so, than the local rosarians' w/ chemical sprays. Hmmm.

I have one rose, Francis Dubrieul, that completely defoliates every summer in the hottest times, but regrows beautifully every fall. I let her be. I would love to have more.

I agree completely with the sceptics. I've grown roses in my present garden for 16 years, increasing my collection from about 20 in the first few years and now have 180 varieties. All roses, old and new classes, were healthy for many years. I was sure my neighbourhood was BS free as there were several healthy Persian Yellows in my street, well-known black spot magnets. I got so bold as to plant several Louise Odier, a rose that gets a minus in the list of one of our most prestigious nurseries. They sell it by popular demand but cannot recommend it. I have pictures to prove how glorious they used to be in my garden. I have only one Lousie (the typo was a Freudian slip I suppose) Louise Odier left and it is leafless already in early June like so many of my older roses. I have kept the last of the Louises because it blooms just under my bedroom window and I like the flowers but I've tried to cover the ugly foliage with a clematis. I shall have to shovel prune it soon with several other bourbons, HPs and moderns that have deteriorated in later years.

I'm new to growing roses, but is blackspot caused by heat and humidity? We have warm, very dry, summers and I haven't noticed any problems unless the neighbor waters my mom's roses with her sprinkler. I haven't noticed any at my house, but I have no close neighbors.

I don't water overhead at night, since the highs in the summer are in the 90's and the lows at night are in the mid 50's to low 60s.

hmmm, some complicated issues going on here. I would come out on the side of the pragmatists in that I know that good soil and the right plant in the right place are infinately preferable to blasting away with sprays but if only life was so simple. What to do about the roses we planted before we knew any better? As rose replant disease is a problem here, the option of just replacing an ailing or inappropriate rose doesn't exist so we have to do our best for the invalids in our care. This may mean spraying with sulphur or bordeaux. Interestingly, where I was born, a polluted industrial mill-town in northern england, no-one ever used to get blackspot. This is a disease of clean air. The overhead foliage spraying comes with problems of its own, specifically rusts and (in vegetables such as potatoes, blight - phytopthera infestans). On the subject of prevention, myccorhiza treatments are proving to be vital for both general health and ability to survive stress as well as invigorating and complementing the root structure. Good hygiene, removing old infected leaves, cleaning secateurs and so on are also good practice but, when all else fails and your beloved Zepherine Drouhin is white with PM, what to do. Well, that is when I spray and doing it early, before bud break, often enables the rose to come through a season without needing supplementary sprays. Finally, I know some of you are OK with defoliation but I hate it. It looks awful, the plants can barely photosynthesise and I actually believe that I am systematically weakening the rose through early defoliation. Also, roses which are free from disease will not remain so for long if there are sick roses in the vicinity. So, spray if it is really necessary with sulphur, copper sulphate, pyrethrum, soft soap, neem oil or cornell, don't use combined pesticide and fungicides, avoid harsh sprays which have imidacloprid (Gaucho?)in and do it in the evening when the bee population are not flying. Balance in all things would be my ideal as well as having a degree of flexibility,innovation and a willingness to learn new things. We are, after all, just a collection of chemicals ourselves.

This all does point out what I hope is a general thought finally getting into the rose growing world.

There are no absolutes and this is not a one size fits all hobby.

Everyone's garden is different. Everyone's expectations are different. Everyone's tastes are different. Everyone's climates are different.

Therefore to me what we can all do is put our thoughts and experiences out there in whatever way we can so we are well informed. After that it's up to each individual to use the parts of the information that work for them personally. AND it's up to all rose growers to respect each individual choice.

I teach what I feel but I try not to judge anyone else or say my way is the only way.

As I always say, trust your own gardener's instincts and do what works for you.

And aren't we lucky the rose is such a diverse plant!

Paul

Interesting observations on black spot and (as a microbiologist, not a biologist) what I would call "acquired immunity".

On the left coast in SoCal, I have my hands full enough with mildew & rust with HTs in my 'first life'. Fwiw, I have not seen your b.s. phenomenon with mildew and plants susceptible enough finally just die as it also infects the canes, this would include most of the orange ones I've had, although Perfect Moment is not bad and of course Marmalade Skies is clean, but also one of my favorites that I think I'm about to have no more, Color Magic. The rest are long gone.

Others are what I would call tolerant in that you see some on the leaves, but it comes and goes with the weather year in, year out and they shrug it off, i.e. Iceburg.

Rust, is more of a nuisance fungus in my yard. It comes, defoliates and goes coming back with the weather it likes. Seems like we get it a lot in the winter. Removing the leaves and a hair cut is not too bad to do on HTs where I have it, especially as the winter infection is when they should be trimmed anyway, and they come back with a new flush.

Paul, I dunno if the word is getting out or not. If I hadn't found this forum years ago, I'd still be thinking it was my fault because I wasn't spraying the right thing or often enough. This year after Jeri finally GramHat'd me enough I've plunged into the deep end with antiques in a big way and look forward to the resistance that we all talk about.

We need a vehicle to make the general public aware what 'disease resistant' really is vs what they see in catalogs and that they really can grow roses no-spray. I know this is the Antique Forum, and even on the other side we make fun of the newer modern roses like the 'Easy' series and others, but I think I embrace their introductions because they may be the vehicle we need to expose people to the notion that they don't have to spray and their roses don't have to look like a mess - they will buy MORE!!! Maybe they will like them so much they will research and find Antiques? Hopefully, eventually, for those that insist on HTs, the big houses will start making fungus resistance a bigger priority when susceptible plant sales tail off after introduction. JMHO...

I just came across this by happenstance, and though the thread is old, thought I'd add my 2¢.

We quit spraying any chemicals about 3 years ago (we have about 10,000 roses for cut-flower purposes) after trying out Actively Aerated Compost Tea in one field. Since starting this, I've learned a few things, and we've got it down pretty tight. It's important to use very good and complete compost (should have humates in the compost), and that it's important to "feed" the organisms when you're spraying them. We do that by adding Fish Emulsion with Sea Kelp to our sprayer at the level on the Emulsion's directions (in this case, 2 tbsp per gallon).

Due to the rains and other problems, we didn't get to start spraying as soon as the foliage came out, and we started having Downey Mildew show up on several roses in the nursery (certainly instructive in finding out which roses are prone to that!), but not in our fields. Anyway, since then we've started spraying everything at least once per week with our AACT/Fish Emulsion, and the roses in the nursery that had DM recovered and have grown out with healthy new growth and flower buds, to the point it's been almost entirely eliminated (some roses haven't really grown out, so it still shows).

We used to spray copper in the winter to prevent DM, but we don't even do that, and I'm comfortable and happy with the results. This not only fertilizes the roses, it has been excellent for keeping our roses very healthy. We do add compost around the roses once every year or so as well, and mulch them.

Anyway, in our climate, it's possible to get every possible rose disease, BS, DM, Powdery Mildew, Rust, what-have-you, and now even the roses that are disease magnets in our fields (Cary Grant, Barbra Streisand, etc.) are perfoming alright, while others are doing extremely well, even this very rainy year.

I've wondered how this would work out in other climates, but I don't know anyone else who does this except the Antique Rose Emporium, which is where I learned about this in the first place (big hat tip and thanks to Mike Shoup!).

--Ron

Ron, Mike gave a terrific presentation on this at the Great Rosarians Of The World event, last January.
This was a very mixed audience -- perhaps largely comprised of Austin Shrub devotees -- and Mike's presentation KILLED.

It left me wanting more to learn about doing this.
If we should set up another Heritage Roses Groups seminar, maybe we can get you to show us something of the nuts and bolts involved.
It's not as entrancing as purty rose pictures, but it sure has my attention!

Jeri

Jeri, I might be up for that!

--Ron

BS spores typically need 6 hours of wet leaves to germinate, provided the temperature is in the right range. In theory, one could "organically" control BS by merely drying off the leaves before the spores germinated, or shifting the temperature so it is too hot or too cold.