22,153 Garden Web Discussions | Roses
That would be my first concern, windeaux. Andrew, there is a very convenient thread about breeding for disease resistance on the RHA, posted by David Zlesak this morning. You might find it interesting. Kim
Here is a link that might be useful: Vance's disease resistance rose breeding review
be kind! I think there are a lot of reasons why people may have boring lawns, and don't take joy in "flowers and bugs and dirt and sweat"
--they may be dirt-and-bug phobic. I am.
--different priorities for their time and money. boring and neat is far better than neglect.
--climate. Traditional lawns and flower beds in my area of the country are a no-go.
My neighbor is very neglectful as a gardener. Nothing ever watered, all browned and dying, nothing ever weeded. And to top things off when her hubby and her put in a raised bed box with landscape timbers they built it up against their front deck only three sided with the back next to the LATTICE, so all their soil keeps eroding away and they just keep dumping in more crap topsoil as a filler. Drives me nuts! I have to bite my tongue! lol
MulchMama, the full paper is not yet available to me through the university. The wording in a reviewed accepted scientific paper is subject to scrutiny by the reviewers and the editor. This wording is also consistent with what I have read in the scientific literature.
The commercial fungicide that they compared with is Topaz (a penconazole based "azole" family fungicide).
For plants I assume that the greatest concern is whether the Topaz is damaging the mycorrhizal fungi relationship with the plant roots.
"Abstract
In order to quantify the importance of ectomycorrhizal fungi on nutrient uptake from the coarse-soil fraction of a haplic Cambisol (alumic), a microcosm study that allowed for nutrient budgets was designed. Ectomycorrhizal- and fungicide-treated spruce seedlings were grown on isolated and cleaned gneiss fragments (6.3 mm > à> 2 mm) from 90 cm soil depth. The substrate was the only source of Ca, K and Mg. Ectomycorrhizal seedlings showed no signs of nutrient deficiencies and biomass increased significantly compared to initial seedling biomass. Ectomycorrhizal seedlings seemed well adapted to survive on the coarse-soil substrate and acquired Ca, K and Mg from the coarse-soil substrate. Gneiss fragments of the ectomycorrhizal treatment were covered by fine roots and ectomycorrhizal hyphae, as observed microscopically. Fungicide-treated seedlingsâ root development was retarded, and shoot biomass only increased from stored nutrient reserves of the seedlings. The suppression of EcM colonization by the fungicide Topasî apparently caused a root growth inhibiting effect. Furthermore, the extinction of mycorrhiza initiated an increased nitrification and acidification and a consequent nutrient cation release triggered by nitrate in the drainage."
A Google Scholar search with the keywords: penconazole and mycorrhizal fungi
Here is a link that might be useful: link for above
With 'Charlotte Armstrong', 'Peace', and their immediate descendants, there was a big step forward in vigor and perhaps in mildew resistance for hybrid teas, but I'm skeptical as to how much improvement occurred in the forty years after that. Over that period the overwhelming majority of new roses were HT and Fl that were fully susceptible to blackspot, and breeding consisted mainly of crossing two successful cultivars of that type. Apart from exhibition form, how were the top roses of the 80s clearly superior to the roses of the 50s like 'Tiffany' and 'Queen Elizabeth'? Is there a super-fragrant red HT better as a garden rose than 'Chrysler Imperial'?
It seems to me that American commercial rose breeding during that period was stagnant except for the pursuit of novelty colors and needle-nosed exhibition HTs. California breeders ignored the rest of America's need for more winter hardiness and blackspot resistance. The groundwork for real improvement was being laid in Iowa, Wisconsin, and Canada, but the truly superior roses never made it to the garden center until Conard Pyle made a deal with Bill Radler around 1990.
This post was edited by michaelg on Tue, Jul 30, 13 at 14:38
Again, depending upon your criteria (in this case, disease resistance and cold hardiness) the answer to the question is going to be "it depends". But, basing it upon the criteria of foliage quality, foliage density, bush habit, vigor, flower production, actual resistance to midew and rust in THIS climate, there have been dramatic improvements in bush, foliage and flower quality. I wish I had my old slides of the decade beds at The Huntington Library I took thirty years ago. It was a living museum by decade (as was the Descanso Rose History Walk, prior to the more recent "renovation" of the rose garden) where you could observe and study the improvements by decade. Viewed that way, the changes have been dramatic. Kim
Michael, thank you for the crash course,
I must say , as a gardener, I have had a very steep learning curve this past 2 weeks.
Soo glad to hear this is not lethal to the plant, I did break a few of the canes when sinking them, I did not take any further precaution than to snip them off and make a clean cut.
Do you have any suggestions on a what I should have in my rose arsenal?
I'm not too fond of heavy chemicals but am resigned to having to step it up to keep the roses healthy.
Thank you, K
Insecticides are rarely if ever needed. Scout for chewing insects and remove them. Bring your pest control questions here.
Fungus diseases very with the climate. When you bring questions here, you should name your state in your sig line or in the post.
In the east, and to a lesser extent in the midwest, blackspot fungus can defoliate most rose varieties repeatedly during the season. This can cause less hardy varieties to die over winter if subzero conditions occur. Some varieties are resistant (ask here) while others are hardy enough to survive without fungicide anyway, though the foliage may not look so good.
Living in an area with extreme disease pressure, I use Bayer Disease Control for Roses. . . (containing only tebuconazole) about every two weeks, to control blackspot and other fungi. It is available at some Lowe's and online. If you want to avoid synthetic fungicides, copper soap (Soap Shield) is probably the most effective option. Sulfur sprays may be adequate if you apply often enough.
Do not buy combo pesticide products (3-in-1 etc.).
That doesn't look like a rust problem to me. Looks like you have bugs chomping on your leaves and your buds. I found this web site that shows photos of common problems with roses, what it is and what causes it.
Here is a link that might be useful: pets and diseases on roses
The netting sounded like a good idea so I spent a day preparing a lot of them. But, my old fingers are not nimble enough. As I would try to tie one around a beetle, it would fly away.
I guess it is back to milky spore, nematodes, and bird houses. (see thread below)
Here is a link that might be useful: link for earlier thread
Japanese beetles are very bad here...pretty much destroy everything from early June through at least July. I've tried many things over the years to control them, but there is no way to get rid of them all. I go out early every morning and cut armloads of buds before the beetles can get them. At least I can enjoy some inside until the beetles are gone for the year.
Thank you, Henry, for this very interesting article.
The point that disturbs me most is that the pesticides cited were most likely properly and appropriately used "according to instructions" (and sometimes many decades ago, in the case of DDT) but STILL ended up in inappropriate ecosystems many miles away with potential for catastrophic damage.
Pacific chorus frogs were used as subjects because they are common enough for "destructive testing", but the frog in real peril in the Sierras is the mountain yellow-legged frog, whose populations are in free-fall (ca. 95% extinct) over the last few decades. Though fish-stocking in high-elevation lakes was the origination of the mountain yellow-legged frog's problems, introduction of toxins like pesticides might be the knock-out blow, given how reduced and susceptible the populations are.
Pam, copper fungicides are quite toxic to aquatic organisms, so of course great care should be taken to avoid run-off contaminating water bodies.
I've been reading the book "Flower Confidential." It points out how commercial flower growers in foreign countries have an enormous pressure to produce disease and insect free flowers--they don't get paid if their crop doesn't pass inspection by the US Government in Miami.
I have this rose on fortuniana from K&M in Mississippi. I had never heard of it before, either, but it was in K&M's sales yard and I could see the beautiful orange from yards away and knew immediately I had to have it. Mine has a STRONG fragrance that you can smell from several feet away. Can't wait to get it in the ground this fall.
andrea - I looked up this rose on HMF, and it is rated "excellent" as a cut flower, so I would guess that the mature blooms last longer than 24 hours. It did say that it was self cleaning, which means that the petals drop off cleanly, instead of staying on looking like dead rags for weeks, but that is a good thing.
Jackie
I have a hedge of 6 Gold Medals and I love 'em. They were planted earlier this year in May and they have grown about a foot taller and have produced blooms non-stop.
The only cons are chili thrips love 'em and the blooms fade to a brownish white, sometimes with a tinge of green.
Thank you everyone for the responses!
My Maria Stern gave me a ton of variants of itself. Sometimes bi-colored, sometimes pink, sometimes orange. I never knew what I would get when I woke up!
When I picked up Gold Medal it had a few buds on it I let it keep. The first one bloomed yesterday, and it was gorgeous! THankfully it Faded little when I picked it today. And I LOVE how it looks next to Intrigue and Red Sensation. Not quite sure who has the better scent between GM and Intrigue though.
These are all in pots on my patio,