I just applied my first round of Messenger on my roses. After reading some of the posts here I'm really psyched about how awesome this product sounds. I'm interested in hearing about any of my fellow GA gardeners' experience with Messenger, esp. on roses. In the past I've used (oh no!) chemicals on my roses to control black spot, which I really hate doing. I was sort hoping to curtail that and see if the Messenger will solve my rose issues. Or should I do both? I think the spray I've been using for black spot is Rose Pride. I've also tried Neem. Both things help, but do not eliminate black spot. I was thinking I could use just the Messenger alone to see how well it controls black spot, but I'm afraid if it doesn't control it that well, then I've wasted time and then by the time I apply a fungicide or something, it's too late. What is your experience with using Messenger on roses here in the deep, humid, hot south?
Using Messenger on Roses
Messenger does nothing for black spot. the hard core rose growers are funny about that stuff, LOL. They treat it like steroids for plants, don't know why they're like that but they are.
Hmmm. Interesting. Well, it still seems better than using chemicals! So far I haven't found anything natural that helps with black spot.
In the rose forum a few people were trying corn meal I believe. The fungus that grows on corn meal will kill the black spot fungus or so the theory went. You would have to ask on that forum because I may not have my facts right on that one. Pretty sure it was corn meal.
Messenger actually stresses the plant into flowering more heavily or at least makes the plant think it's under a lot of stress.
I am going to chime in here on this one....
I have only been in OH for 4 verrrrrrrry Looooong years...Prior to that I lived in FL and GA...Can't get much worse for roses than FL with the humidity...
I got in on a Co-op this year for Messenger to use on other things besides roses...this will be a first for me...I am told that it helps stimulate growth for stronger plants as well as bloom, but nothing was said about black spot...
I found in FL, that if I planted my roses out away from walls, fences etc. and no plants around them to restrict air flow, that I rarely if ever, got any of the typical rose problems including powdery mildew or black spot...
I was taught by my GrandFather who had dozens of roses up in MI, that in the event you do get it, you need to remove all affected leaves including those on the ground under the bush or you will never eradicate it...Strip off and dispose of remaining leaves. Spray canes and soil around roses with dormant oil and lime sulfur to kill overwintering insects and fungal diseases in the early Spring...
This is a link to a MI nursery that is no longer in business, but was for many years, and they have the best advice for pest and diseases ever...It is exactly what my GrandFather taught me...and it works...
http://www.greatlakesroses.com/careofroses.html
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I found that Messenger did not KILL black spot, but it, a lot of compost dug into the soil & adding minerals really helped me have soil with good drainage and the ability to go longer between waterings which has helped keep soil evenly moist and the plant is healthier. My roses are much more resistant to BS then - and Serenade really helps too with BS.
FL
I know I am a little late to this thread, but, I put 1 part vinegar to 10 parts water, add some (maybe 2T) Epsom salt, and a little bit of Dr Bronners pure castile peppermint soap to it and spray on the leaves. If I happen to have some kelp meal around I will add that too. You can also add some Black strap molasses. Spray this on the leaves, and sprinkle cinnamon on the ground. The vinegar will help with the black spot, cinnamon is a natural fungicide, epsom salt, molasses and kelp will help the bush as far as making it healthy, the soap makes it all stick to the leaves, and the peppermint repels some insects. Hope this helps.