Hi there again :). I am off today and obviously spending too much time online lol. I tried being no spray this year but gave up 3 weeks ago. I am not an expert on the subject, but I’ll tell you what I do and why.

Rotating is important to prevent the organism from building resistance to the medication. Using more than one drug is very common in human medication treatments, specially when dealing with organisms that can rapidly change. Bacterias for example have lots and lots of ways of acquiring resistance factors through plasmids, resistant binding proteins or other ways. Same concept for the organisms that affect our gardens. By using drugs that act by different mechanisms you can prevent the fungus from figuring out a way to become resistant. I normally go to the store and buy Bayers and a couple others with different drugs in it. Then alternate them. This allows me to not have to use any of them too many times. I definitely use Bayers more than 3 times in a year, but just never back to back.

Hope this helps. I don’t remember of the top of my head the other brands I have on my shelf right now but I’ll update when I get a chance.

Agree with what Dr Dianela said above :-)

Typically you use one contact fungicide and one systemic fungicide together. When you rotate, you use a different contact and a different systemic.

In your case mancozeb is your contact, tubuconazol is your systemic. (Double Check your Mancozeb dosage, I believe it’s 1 TBsp/gal).

I primarily use primarily Propriconazole and Mancozeb every three weeks. Once in the spring, and once in the fall , I’ll sub with Daconil (contact) and Cleary’s (systemic). The Daconil can burn in hot weather. As long as I’ve been doing this, I have pretty much wiped out blackspot, while everyone else in the area has bare sticks for rosebushes.

I made a laminated sheet of all the stuff I use. Note: I only use an insecticide when I see a specific pest, not on any regular basis.

Christopher very Interesting and detailed explanation or your plan of action. I might experiment with some of the things you mentioned.

Ben T I love your laminated sheet and I think I may need to copy you on that. I also like spinosad and have used it with good success in the past. I have no sprayed for bugs this year hopping to get more beneficials, but I am keeping the spinosad close by just in case.

Where do you find Lime Sulphur anymore? I used it in my orchid/fruit gardens for years but I've looked for several years now and it is gone for even a mention. I tried to research how it's made but couldn't find that either. I agree with everything said on the types and rotations. I know I would have fabulous roses if I went back to spraying.

There is a case of bottles at my job, probably from a few years ago but not expired. I took a look online, and it is hard to find now. However, I noted that it's available as a concentrate for a pet-dip. The ingredient (calcium polysulfide) is the same.

:-)

~Christopher

I enjoy ALL types of roses and will do what is necessary to keep the foliage clean and the blooms looking good. I start in early spring and spray on or about the 1st and 15th of each month. Starting early as a preventative has been the big thing in my garden. I use Bayer Disease Control and Mancozeb on the 1st and Propriconazole and Mancozeb on the 15th. Works great for me.

This is such good info, thank you all!

Dianela, thank you. Yes the practicality of microorganisms developing resistance is a problem for us humans isn't it. With Bayers and the few others suggested I will work out a game plan as needed.

BenT: Thank you for the chart. You are always organized. Is there a reason you halve the dose of protekt when you make 4 gallons? Or is that a typo? I used potassium silicate as a foliar spray at a little higher dose on my hydrangeas this summer and the effect was jaw dropping. There was no more drooping after that. Maybe protekt will help towards microorganisms, insects and heat too. Yours is a simple schedule that I can try. Thank you so much!

Ken: marking off dates is such a good idea. Thank you!

Christopher: Thats such a great plan. I will try something simple for sure but I will save your write up. What I love best is the lime sulfur spray very early spring or late winter to burn off the leaves and any lingering infections. The leaves that fall on the mulch from this treatment do you remove them? Do you spray the surface of the mulch? And I should look to buy calcium polysulfide? The concentration to use will be marked on the bottle or is it? What is pet-dip? Thank you so much....

Katya

I think its only 1/2 tsp per gal for Protekt...I only noticed the typo too once I posted my screenshot :). Good to know it makes such a difference on the hydrangeas. I cant really see a difference on roses since rose leaves are pretty tough and leathery, but the purported benefits are great and my leaves look good.

Dianela

I agree, Spinosad works wonders on Thrips...before I found it, I really had no way of controlling them.

I looked up calcium polysulfide. Its a liquid concentrate, same as lime-sulfur that has to be diluted in water. Its not that hard to find. But how much to use varies depends on what you want to achieve and time of year. Its a little confusing as a first timer. I will continue to read about it and maybe someone who knows might comment. :)

I do a dormant oil spray early in the season and have found it helps a lot. If I need to get leaves off I will then use sulfur but last winter the leaves fell by themselves. So I waited a month for that.

Christopher:

Could you kindly provide a link to the government (or like) site which discusses that imidacloprid, in all its iterations, will not be sold/produced in the US after 2020?

Vap, thanks! I was wondering if one can use dormant oil spray on roses. I just read an article where lime sulfur is combined with dormant oil for fruit trees in late winter.

https://homeguides.sfgate.com/use-limesulfur-spray-48838.html

Some articles recommend washing off the lime sulfur spray 15-20 mins afterwards. Do you do this?

https://www.finegardening.com/article/lime-and-sulfur-spray-great-way-to-knock-down-fungus-on-your-roses

rifis -- see below.

https://www.govinfo.gov/content/pkg/FR-2019-05-20/pdf/2019-10447.pdf

:-)

~Christopher

It is my understanding and in reading the above article that imidaclopid itself is not being taken off the market. Any product that contains one of the ingredients listed on Table II from the article, - such as the Flower, Rose and Shrub Care III which contains clothianidin AND imidaclopid will be discontinued. Only the clothianidin is the one being discontinued. There may be other combinations of products that contain nonrestricted fungicides and imidaclopid that will still be available. Subject to interpretation.

Will the deer be happy that imidaclopid will still be available (and any female humans)?

https://www.google.com/search?q=deer+birth+defects&newwindow=1&sxsrf=ACYBGNS-txn1_5jdjpaBieXMqnRSLoZRMA:1571409284600&source=lnt&tbs=qdr:w&sa=X&ved=0ahUKEwjj2dHhg6blAhVyCTQIHU3YDcMQpwUIKQ&biw=1029&bih=515

Here we go.

Does anyone here use lime sulfur in late winter? Do you just spray it on and leave it on or wash it off later?

I believe if the lime sulfur is used early to remove leaves or as a dormant spray it is not washed off. I only use the dormant oil which is not washed off. I have to wait a month to use plain sulfur so as not to burn anything in the spring. After that I will also use sulfur with a surfactant alternating with the Cornell mix. However, I do not use oil in my mix since there may not be a month before using the other.

Thank you Vap! What I read in one of the articles is that the lime sulfur and dormant oil are combined and sprayed in late winter. Do you think that would work on roses? I am asking as I have never done this before and I cant find information if that mixture can be used on roses. If it can be, then you could reduce the count of pests year to year, perhaps greatly.

yes, I have read you can do that with roses. Even just using the oil alon really help with early-season pests.

Hi everybody!

I am getting ready do my first round of spraying for fungal infections...while I realize I am somewhat late already. I never got to the lime sulfur.

I just planted some bare root roses from Palatine that have tiny buds emerging. My question is can such young roses be sprayed safely? Does there need to be any adjustment for dose of the chemicals? Or is it best avoided at least for a few weeks? I can imagine pros and cons either way but want to check with you...

Thanks for your help!!

Did you get any oil? I recently read to use an oil spray mixed with copper as an early-season spray. I just used oil because I can't go to the store to get copper unfortunately.

Hi Vap! No I havent. I do have some horticultural oil but no copper either. Is it worthwhile spraying with oil now...most of my roses have leafed out a great deal already? I was just going to go ahead with the chemical fungicides..

Are you very hot there yet? Here we are still cool if with some quite warm days recently. I think if you were below 80° you can use a light mix of oil. Do not use the heavy dormant spray if you have a lot of leaves maybe somewhere between the two. This has helped my roses immensely. I don't get scale or anything that it helps with but I don't know why since I've been doing it there fantastic who the first flush. The only thing is you cannot use sulfur within a month of the oil which is what I use. So for my next Friday I use baking soda. But if you have a fungicide you can use that next. I have not used copper before but I was recently reading Grace Farms schedule for spring and she did that for her early spring. If you go to her sight I think that she gives her exact instructions. She gives two oil sprays once dormant and once once the leaves come out. Out of curiosity, what fungicide are you going to use?

I was thinking of starting with mancozeb and tubuconazol and then rotate with Propriconazole and Daconil. I have been reading interesting things about how to improve a plants immunity...I will probably post about it eventually. Who knows if such measures work to a degree that they are practicable for rose care.

Its not hot at all, reaches 60 during the day most of the time. I will google this Grace Farms..dont know about her...Thanks

Actinovate and protect. I think I saved the thing for Grace Farms I will post it here ar if I find it.

https://manage.kmail-lists.com/subscriptions/web-view?a=P6QcP9&c=MbPaZy&r=pSjApch&m=LjGJNA&k=64a1a7b368354fdf5916fc58a68b3e2e

Thank you for that! Very nice website.

Sadly Vap actinovate did not work for me. Theoretically very nice concept and I was quite excited about it but just was not effective enough in my garden. Gave it a good shot. But I will continue to try biological and organic control.

So do you think its ok to spray a just planted bare root rose that is budding???

Yes, I did mine that way as they started budding out so early and they are fine.. I also did my newly planted bagged roses. In fact, I find it best to deal with new plants more aggressively since it's a vector of insect introdiction. I probably wouldn't use the dormant strength.

I've never used either Actinovate or Protekt. Did the former help at all or just not enough? I have a couple of roses that aren't total BS losers, but are just a bit iffy at times.

I'm glad you enjoyed that link. I get her stuff via email. and find it useful to see what professionals use. Of course, I don't think she has heavy BS pressure, but her roses must be almost perfect. I don't remember how many roses you have, but I have multiple sprayers and found a small pump model useful to do just a few. Don't ask me about my recent experience with one I thought was my mosquito sprayer, but ended up being a damaged one a friend gave me to fix. So PLEASE, inspect your equipment before filling with oil (or even worse) and spraying under pressure!!!

I know silicone (protekt) sprayed on plants has a lot of value. For my hydrangeas it was like night and day with just one application. I did not, could not, make careful observation with my roses as my garden had been neglected for a very long time and BS was out of control last year. In theory if you have time and spray with protekt it can help in more than one way. Dosage is important.

Actinovate, well I would say is not worth it, and essentially did not work. You have to spray thoroughly every week. If it rains you have run back out and spray again. And even with all that did not do that much.

There are other substances, not necessarily man made chemicals with possible toxicity, that can significantly improve a plants chances of not getting infected, particularly if they are not that vulnerable to start with. One such is silicone. Let me go back to my reading and I will bring up these topics.

I know what you mean....I have begun to label everything B-O-L-D-L-Y and test before use.

Serenade also mentioned by Grace Rone Farms, didn’t seem to help at all when I tried it. The mode of action is fascinating, it just didn’t work. In all fairness I only tried it once. I hurried back to my old buddies Propiconazole and Mancozeb and begged for forgiveness, they forgave me for spurning them, and clobbered all the black spot.

We don’t really get black spot in California since we have dry air. So I am guessing Serenade is better for powdery mildew and rust, which we do get especially in the spring and fall. Plus they use other beneficial microbes and oil sprays with neem and copper as well. I am trying to adopt their regimen, since I live in the same climate and when I visited their farm last fall I saw no disease on the roses, which was impressive.

Oh and another thing is that we get ZERO rain June through September, so that would make a big difference in how well the sprays work and how often you would apply.

This is what I suspected. Thanks for the clarification. We go 3 weeks without rain and call it an official drought.

This problem has been pointed out before,

https://www.gardenweb.com/discussions/1643641/concerns-of-tebuconazole-resistant-isolates#n=0

but perhaps the present corona virus situation may make more readers take notice:

"Aspergillus fumigatus is the mainly leading cause of invasive aspergillosis associated with significant morbidity and mortality in immunocompromised patients."

"This strongly implies that conventional application of tebuconazole for plant protection will cause resistance of A. fumigatus to triazole medicals in agricultural soils."

https://www.ncbi.nlm.nih.gov/pubmed/30340269

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

Title: "Antibiotic Resistance Could Lead to More COVID-19 Deaths"

https://blogs.scientificamerican.com/observations/antibiotic-resistance-could-lead-to-more-covid-19-deaths/?utm_source=newsletter&utm_medium=email&utm_campaign=today-in-science&utm_content=link&utm_term=2020-04-01_featured-this-week

I tried Serenade too, with great commitment but it did not work in garden.

😟🙁

I sprayed mancozeb yesterday for the first time and there is still residue on the roses today. Is that normal?

i did use 2 tablespoons to 1 gal because that’s what the instructions said. I think others only use 1 tablespoon?

Residue from mancozeb is normal.

Remember that mancozeb is a contact control. You may need to use a systemic like Bayer Disease Control or Propriconazole. I'm like Ken in that I rotate between Bayer Disease Control and Propriconazole. I add mancozeb in the summer when blackspot is bad

I often see a little residue left from mancozeb. You know I was using 1 tsp per gallon and it still worked great, of course in combination with a systemic. I dont think you need more than 1 Tbs per gallon. Its your call but best not to use more chemicals than needed, both because they can be toxic and develop tolerance in the bugs.

Thank you, Glenn and Katy!

2 tbsp seems like way too much! I’ll start using 1tsp instead.

I already had pretty worrisome blackspot so I used it right away. I got propriconazole yesterday and sprayed that as well.

Next time I’ll mix the two and at lesser dosages. I’ll be unconcerned once the plants are big enough to shake it off. They are so tiny right now and had major struggles last year.

I appreciate the input and guidance so much!

Henry, do your links suggest that by using these fungicides, I may potentially develop antibody resistance?

I need a dumbed down post.

jc_7a_MiddleTN , no, to cite a specific situation, the bacteria in your soil can become resistant to the azo type fungicide that you are using in your garden so the similar azo type drugs that are used to fight that bacteria (which you can inhale, when you work in your garden) - when it infects you - may no longer cure you.

Thank you for explaining that!

Similar to fungicide, can anyone recommend a good systemic insecticide? In particular, "thripicide" and "japaneese beetlecide" :D

Ideally I would like avoid spraying every couple of days like some pages recommend with neem oil, knowing it causes leaf burn etc.

I am not aware of a systemic or JB's. Milky spore seems to be the solution applied for a couple of years. On your lawn and perhaps your neighbors if they got a lot of them too. I picked mine off in soapy water but we do not get as many as others on this forum. In general I try to avoid systemic switch kill anything which feeds on a rose including moths and bees. Unless you can time your application to avoid flowering. But of course that wouldn't help your Japanese beetle situation.

Hi Everyone!

I did not spray any type of fungicide on my roses at all this season. Many of my new roses, ones that were planted last fall, got brutal Black Spot this summer. All the leaves are/were gone. I have never seen such naked plants. These were mainly the modern roses and David Austin roses. Now the surface of the mulch below them is covered with yellow infected leaves. Some of the leaves have already decomposed and some are breaking down. And people are walking over the area going here and there spreading the spores everywhere. Some spores are washing into the soil, I bet. And I can only imagine just how badly the spore count has increased in my garden.

I am wondering if I should spray the affected roses and the surface of the mulch at least twice, one week apart. Then cover the whole area with a very thick layer of mulch and re-inoculate the area with beneficial soil microorganisms,

Would that be enough to kill off most of the Black Spot? Or would I need more applications?

I often see recommendations not to spray the ground. So as to not harm soil fungi or prevent contamination of groundwater? Or both? I have also seen people with fruit trees spray the ground around their trees routinely. Is it a bad idea to spray the surface of the mulch on a dry day? I just want to mitigate this BS crisis but not do further harm. Covering with more mulch will help, I think, and with a rich population of soil organisms the spores will get eaten.

For the above spraying I would use Bayer and Mancozeb. I also have Infuse. Do I need to alternate this late in the season?

I also got tomato early blight this season. It has never ever happened to us. My husband bought a tomato plant somewhere and I noticed the funky leaves but before I could think the fungus was on all the plants. Some plants died and most are holding on by a thread. I have heard Daconil can work. Do any of you know if Daconil is at all effective if the plants already have been infected? Is there any other fungicide that can be used on tomatoes?

Thanks a bunch!

PS. Bonide's Infuse which is Propiconazole 1.55% is not being sold by Amazon anymore. That is where I got it. Some say it is killing there roses. The instructions on the label say to use 2 Tbs per gallon for BS. @BenT (NorCal 9B Sunset 14) suggests 1/4 tsp. What is the effective concentration of Propiconazole in water to treat BS in roses? It could also be there is some problem with Bonide's production or formulation.

Propiconazole if used per the label does not kill roses. Rotate Propiconazole with Bayer Advanced disease control and add manzate during periods of high black spot pressure. You can get Propiconazole at Rosemania.