IceBird,

Blackspot spores travel on the wind, and begin to grow under the proper conditions. These being temperature (40-80 degrees here) and moisture. So there is never really a way to get rid of the fungus unless you use fungicides or purchase disease-resistant plants. The problem with fungicides is that they're toxic. Tebecazunole (Bayer) has shown to cause seizures in animals and have devastating effects on the human endocrine. If you have fragrant roses that you spray, taking a whiff of them means you are inhaling the chemicals. Children are especially susceptible to them as their smaller size means it takes less to affect them. Even the bees are harmed by the fungicides, with them being attributed to the decline in bee populations alongside insecticides.

With that being said, the old, ratty growth you see on your roses will fall off as the new spring growth comes in. You can tidy up the bushes by pulling off the affected growth, but the plant should clean itself.

One thing to consider is that the fungicides may be killing off beneficial insects which prey on thrips. When my plants show thrips in their blooms, I disbud the entire bush to try and stop the life cycle of the little buggers.

Josh

This post was edited by JoshTx on Thu, Feb 27, 14 at 20:57

Josh, what does "debuff" mean? You are right to warn against using those Bayer products, IMO,and all kinds of sprays must be used with great caution. When I first began growing roses,I had tons of aphids all over. I was worried about insects in general, and was particularly distressed by the beetles (Oxythyrea funesta) that ruined the flowers,so I started spraying once a year with a systemic insecticide Bayer's "Confidor" here in Europe (imidacloprid).The aphids disappeared,the beetles got worse than ever, and now I have thrips. Apparently, the aphids somehow actually prevent thrips,which I did not know! So, no more insecticides for me!
As for bspot, I spray with copper (Bordeaux mixture, for example).You can also try Google-ing for organic treatments; one is spraying a mix of skim milk and water, I believe. I would use one of these if I had fewer roses; I only use copper because my garden is just too big and I can't spray often. It's also far away from my home...bart

Well, you have started a controversial thread. Every time this topic comes up, opinions (and hot tempers) start flying in every direction.

First off, most posters on this forum (or so I would guess) do not think the cornmeal treatment for BS is effective at all.

Secondly, there seems to be some confusion above whether we are talking about insecticides or fungicides. Insecticides kill bugs; FUNGICIDES DO NOT! Fungicides are for treating DISEASES (NOT INSECTS).

A lot of us here rarely or never use insecticides. There are other ways of treating most bug problems (though nobody knows how to treat the Japanese Beetle). Those Bayer products that are advertised as 3-in-1 or 2-in-1 or some such "combo" should be avoided--they have INSECTICIDES in them. If you want an effective FUNGICIDE for disease, (NOT an INSECTICIDE to kill bugs), Bayer puts out a product called Bayer Garden Disease Control of Roses, Flowers, and Shrubs--if you are going to spray, I recommend it.

If your only problem is a couple BS leaves on a couple potted plants, I would not spray--just go over and yank off the BS leaves and dispose of them in a trash bag.

If you have a widespread and persistent enough problem with BS throughout the garden, then you have basically two choices. (1) Spray using the Bayer fungicide (but NEVER the Bayer "combo" products); OR (2) toss all your bs-susceptible roses and start researching for BS-resistant roses to replace them.

If you do spray with a fungicide, read the directions first. They list some precautions and give helpful advice. For instance, spray earlier in the morning on a wind-less day (so that the wind won't blow fungicide in your face.) While it is not listed as dangerous to kids and pets out of the yard, as a precaution you may want to keep them out of the yard until all the fungicide has dried. Again, read the label carefully--they list the kinds of critters that may be affected by Bayer Garden Disease Control for Roses, Flowers, Shrubs. Of course, if you ignore my advice and pick one of Bayer's "combo" products, then all bets are off--because the "combo" products contain insecticide (along with fungicide and/or fertilizer). And if you spray, get an extension "wand" so that your reach extends way beyond your arm--and you can thus stay further back away from the spray. Read the labels for other Do's and Don't's.

Spray as little as possible--and only spray the roses that need some help controlling BS. Unforutnately, in some parts of the country, gardeners find themselves in BS-he!! and thus have to spray every 2-3 weeks all season long. Myself, I'd go look for some more disease-resistant roses so that I didn't need to spray that often--but then I've never lived in BS-he!! --so I can't really say what I'd do under those circumstances.

And now I'll predict that several posters will arrive on the scene and vigorously denounce me for the "moderate" approach I advocate here. To them, you must rave against fungicides, or you are a hopeless renegade!

To each his/her own, I say. : )

Good luck.

Kate

Dr. Bronner's castille soap peppermint diluted in a spray bottle with water helps to control blackspot and aphids in my garden.

The following statement was made: "Insecticides kill bugs; FUNGICIDES DO NOT! Fungicides are for treating DISEASES (NOT INSECTS)."
------------------------------------------------
I suggest that the above statement be modified to include: "fungicides were not designed to kill insects, but that does not mean that they do not have effects on insects".

As an example, in the linked to thesis use your PDF find command with the keyword tebuconazole.

http://www.dissertations.wsu.edu/Thesis/Spring2010/j_wu_042110.pdf

Here is a link that might be useful: link to recent thesis SUB-LETHAL EFFECTS OF PESTICIDE RESIDUES IN BROOD COMB ON WORKER HONEY BEES (APIS MELLIFERA L.)

Kate,

I would hope that no one would denounce you for having an opinion. While I find myself in the "rave against fungicides" camp, it is merely for ethical reasons. However each of us is able to make their own decisions, and if one finds spraying acceptable then it is not my place to criticize their gardening methods. But I do feel compelled to voice my own opinion against spraying, as I am sure the companies who produce these products are not forthcoming with the information. I only hope to educate people, as without education people cannot make a choice. I would hate to see someone suffer the effects of these chemicals if it could have been avoided had they known.

Josh

JoshTx another point against spraying tebuconazole fungicides is introduced in the following thread:

Title: "Which is more important roses with no fungus or curing people?"

http://forums2.gardenweb.com/forums/load/roses/msg0700303532460.html.
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In addition to the scientific paper abstract linked to in the above thread, I suggest reading another scientific paper available at:
http://www.plospathogens.org/article/info%3Adoi%2F10.1371%2Fjournal.ppat.1003633#ppat-1003633-g002

Title: "Emergence of Azole-Resistant Aspergillus fumigatus Strains due to Agricultural Azole Use Creates an Increasing Threat to Human Health"

Here is a link that might be useful: link to earlier thread

...in any case, if you really want to spray, why not use copper? It's not a poison,just a metal.It works well, too. Or Bordeaux mixture...why buy some poisonous chemical fungicide mixture???

Thanks for all the comments. I'm leaning towards the copper idea. Anyone have some recommendations of products that are readily available and won't cost me an arm and a leg?

Since only 2 of your 30 roses are showing spots on their old leaves, seems easier and cost-free to just remove & trash those leaves. A pair of sewing snips or manicure scissors works well if you don't have flower shears. Usually hold a small paper bag to catch the snipped leaves as they fall. For leaves harder to reach, I use long metal kitchen/barbecue tongs to avoid any thorns. Wash those afterwards. Common practice to clean up & remove any fallen rose leaves on the ground & trash them, too. Two bushes done this way at a leisurely pace might take 20 minutes on bushes of average size

Environmentally friendly & free.

This post was edited by vasue on Fri, Feb 28, 14 at 10:16