If you look at the base of the dying stem, there is a brown spot there which may be girdling the whole diameter or nearly so. This is a canker that has killed the bark. If dead bark girdles the stem, the stem must die. There is another canker at the top of the stem which started at a pruning wound. This stuff happens. Just make a clean cut at the very base of the stem and it will probably heal cleanly. Cankers are fungal infections that invade wounds usually during cool damp weather. You can't prevent them altogether. It helps some to make routine pruning cuts only 1/4 inch above a leaf or former leaf site rather than leaving longer stubs above the latent growth bud. The plant will not defend these stubs, so canker will usually develop there.

Michaelg,
Thanks for the info! I will prune closer to the leaflet.
Kyrose

Spot on, Michael! I do a lot of my dead heading as I walk my roses and I just snap off below the hip. I get this exact same thing some times as a result and it's always on a cane that I snapped off instead of doing actually clipping dead heading. The tip where the bloom was goes brown and then slowly the cane yellows from the top down. I'll have to be more vigilant about not just snapping wilted blooms off!

i believe it is a fungal infection from the mulch. i have learned from rose experts here in the north east to rake off the wood mulch and try to use something else. The harsh winter we had made the rose weakened and got the fungal disease from the wood mulch. The public rose gardens here in the northeast do not use wood mulch. Wood mulch is instant death to a rosebush grown here with our damp short growing season.

i can understand how important the wood mulch is to roses grown in the southeast to preserve the soil. i know rose experts in the Carolinas disagree with my viewpoint on wood mulch. Maybe in Kentucky there are other mulches with less fungus.

Seil, when we snap off blooms, the neck always dies back, but in my experience it stops at the abscission joint at the bottom of the neck. I have snapped off thousands of blooms and will continue to do so.

I also doubt that mulch has anything to with it. Everybody uses organic mulch. Again, occasional canker or dieback is normal, and I don't think we need to spend much energy worrying about it or trying to prevent it. It the present case, it's just one small stem.

This post was edited by michaelg on Fri, Sep 12, 14 at 11:12

The editor of organic gardening magazine would say that wood mulch close to the stem would cause that. Organic mulch stored improperly like in a plastic bag would cause anaerobic process not good for plants. Most gardening experts say to keep wood or bark mulch atleast 6 inches away from the stem.

Occasional canker is not normal. i disagree. Wood and bark mulches breed fungus. Canker is the most serious of the fungal diseases and can kill a plant. Also it is important to rake fallen diseased leaves. There is a saying here.
" just because everyone is jumping off the empire state building doesn't mean you should. "

This post was edited by sam4949 on Sat, Sep 13, 14 at 4:54

I've been doing OK with organic mulches for 38 years, I don't keep it pulled back from the stems, and the only plants I've ever lost to canker were fall-planted roses that were mounded with dirt and then caught in a December warm spell that caused them to start into growth.

Every wild rose in the woods has an organic mulch over the base of the canes.

http://www.cleveland.com/insideout/index.ssf/2012/06/artillery_fungus_which_thrives.html

The mulch in the picture looks to be recycled pallets. This mulch has microbes scavenge Nitrogen from soil and less nitrogen for plants.

http://www.oardc.ohio-state.edu/hermslab/images/Mulching_the_Landscape_Effects_on_Soil_Ecology_and_Plant_Health.pdf

Wood mulches “tie up” the available food in the soil, a process known as “nitrogen immobilization”. How? Wood is carbon, which is why it burns so nicely. However, carbon looks for nitrogen to bond with so it can break down. Wood mulch takes nitrogen right out of the soil. That’s the same nitrogen that plants love. A Stump ground sawdust and fine chips wreck havoc for years, making it impossible to establish new grass growth in the area.
Dyed wood mulches are also suspect for having old pallet materials ground into their base materials.
According to gardening expert Mike McGrath (WHYY, Saturday A.M. “You Bet Your Garden; his site “GardensAlive.com”) his favorite “mulch expert” Ohio State Professor Emeritus Dr. Harry Hoitink, warns that dyed mulch is especially deadly when used around young plants or in brand new landscapes.
Wood mulches can also host “artillery” or “shotgun” fungi, a nasty fungus that can turn adjacent structures black.
Mike McGrath was Editor of Organic Gardening magazine 25 years.

Question. Dear Mike: We haveused black shredded mulch in the flower and shrub garden in front ofour house for several years. After listening to a recent show, I'm nowwondering if it might be part of the reason many of our seedlings don'ttake and my wife's perennials don't come back. If the mulch is toblame, what are our alternatives for preventing weeds while alsodressing up the appearance of the front of our house?
---Michael in Mount Laurel, NJ.

Mike: What kind of mulch should I not use? The last 2 years I have usedLicorice Root type mulches, but now I have black spots on my patio thatlook like soot. And what can I
do to get the spots off? Thanks,
---Anna Marie, a teacher in Cherry Hill, NJ

Answer. I have been warning peoplefor years that wood mulches wood chips, shredded bark, sawdust, andthose increasingly popular 'root mulches' can breed 'shotgun' or'artillery' fungi that shoot tar-like spores as far as 30 feet towardslight colored objects, like the side of your house or car. These sporescan be removed pretty quickly if you get to them right away, says Dr.Dan Herms from Ohio State University: Soak them thoroughly with soapywater for a few minutes to loosen the natural 'glue' they exude, thenscrub them off vigorously. But as we have always warned, once the spores dry they are virtually impossible to remove without destroying the surface they're adhering to.

Wood mulches can also slow the growth of established plants and yes,just plain starve new ones to death by 'tying up' the available food in your soil, a process known as "Nitrogen immobilization". Wood is carbon; carbon always looks for nitrogen to bond with so it can breakdown into new soil that's the principle behind composting. Wood mulches take that nitrogen right out of the soil, out-competing your nitrogen-needy plants. And dyed mulches are the absolute WORST offenders; the wood in these old pallets chipped up and sprayed with dye is the worst type for use around plants. Our favorite mulch expert,Ohio State Professor Emeritus Dr. Harry Hoitink, warns that dyed mulch is especially deadly when used around young plants or in brand new landscapes.

There's also another problem that occurs around this time of year, when sap filled trees are chipped and shredded and the mulch sits around all piled up. Dr. Hoitink explains that this sap becomes a high-strength vinegar, with a pH as low as 2.5; no plant can survive such an acidic attack. So doubly beware of wood mulch with a sour, vinegary smell. Heard enough bad things about wood mulches yet? (We'll post links to Ohio State and Iowa State horticultural bulletins about these and others dangers with this Q o' the week.)

So what SHOULD you use? Our new mulch maven Dr. Herms (Harry is retired and wants to pass his well-mulched torch) warns against using one of my old favorites, straw. He says that straw is carbon-rich enough to cause some of the same plant-food stealing problems as wood,and that it often contains seed heads that can cause weed problems(which we've warned about in the past) AND attract rodents that will then look for other trouble to get into on your landscape (which I hadn't thought of before).

He does think highly of my personal mulch of choice, shredded Fall leaves but doesn't think it's the absolute #1 choice. Both he and Harry feel confident that, after many years of active research, they have uncovered the BEST all-around mulching alternative.

You ready? It's compost.

Now for years, I've been telling people that compost is a great soil improver, plant feeder and disease fighter, but that it didn't qualify as 'mulch' because it wouldn't prevent weeds or retain soil moisture as well as shredded leaves. WRONG, says Dr. Herms.

"In a recent study at Ohio State, we kept track of 'weeding hours' for plots that were mulched with either 2 inches of compost or ground wood,and there was no difference between the two," he reports. "Both mulches reduced weeding time to 1/20th of that required to weed an un-mulched 'control' plot." So, solid University research now shows that two inches of compost controls weeds as well as a 'conventional' wood mulch!

And Dr. Herms who is not an organic researcher by any means; he used the nasty chemical herbicide Round-Up to kill the existing weeds in his plots adds that compost greatly enhances plant growth, while wood mulches slow it down or just plain kill the plants. He also feels strongly that the look is just as attractive as dyed wood. "I use compost to mulch everything in my home landscape", he told me. "The rich black compost really sets off the green of the plants and the colors of the flowers beautifully. In fact, it looks just like a dyed black mulch but without all of wood's downsides."
Unlike wood mulches, you do have to apply to apply a fresh inch or two every year to keep weeds at bay. But Dr. Herms adds that this compost will also greatly limit disease and insect problems in the plants it mulches and improve their overall vigor and root growth; wood mulches,he notes, often have the opposite effect. And, he adds that, "adding fertilizer to plants mulched with compost had no effect at all; the plants simply didn't need any more food." Plants mulched with wood needed lots of added fertilizer.

So there's absolutely no excuse for risking your landscape, your home's siding, and your car's paint job with wood mulches. Every large garden center has big piles of compost they'd be happy to deliver, just like wood and bark mulches. Just remember to keep ALL mulches six inches away from the trunk or stalk of any plant; any mulch will rot a plant it's piled against. Keep all mulches six inches away from your home as well; termites will use ANY moisture-conserving cover even stones to reach your framing.

This post was edited by sam4949 on Mon, Sep 15, 14 at 21:44

http://www.gardensalive.com/product/is-your-mulch-magnificent-or-miserable?ai=552

The latest research on mulches, from Iowa State & Ohio StateUniversity:
http://www.extension.iastate.edu/Publications/SUL12.pdf

Dr. Harry Hoitink's classic bulletin on wood mulch problems from OhioState; includes photos of shotgun fungus damage and other nuisancemolds:
http://ohioline.osu.edu/hyg-fact/3000/3304.html

Dr. Hoitink's home page, with links to lots of research articles onmulches:
http://plantpath.osu.edu/faculty/hoitink.php

http://www.therockpile.com/wp-content/uploads/2010/01/OSU_mulch.pdf

Wood mulch is not nice .especially dyed wood mulch.It's made by grinding up old pallets and other trash wood, and may contain arsenic,creosote and other nasty stuff. It is the lowest quality mulch you can buy.

This post was edited by sam4949 on Mon, Sep 15, 14 at 21:36

LINK WARZ!

See the following from Dr. Linda Chalker-Scott, a horticultural scientist who knows the research on mulches and has contributed some herself. Wood chips are excellent if you don't have leaves or pine needles on your property. Call a tree guy and ask him to dump a load when he is in the neighborhood. Should be free or maybe ten bucks. Great for the garden, no shipping / energy costs, and it keeps stuff out of the local landfill. Or use whatever else is cheap and local.

Here is a link that might be useful: wood chips

What was with that flood of posts by the earlier poster? Is he just carrying on a long monologue with himself? Or does he really think he is interacting with other real life posters?

Weird. Reminds me of an earlier poster who used to post message after message after message--in a row. Oblivious to the fact that no one was responding to any of them. Hmmmm.

Kate