Snapping off spent flowers or lightly pruning back to a good leaflet shouldn't cause canker. Perhaps the brown you are talking about is the short distance between where the bloom was and the next leaf growing out from the cane. It is normal for that segment--say, 2-3 inches long--to turn brown. The new leaves and buds will form back down the cane at one of those places where the older leaf already exists, so if you want to avoid those little brown "sticks" at the end of the cane, just trim off the cane back to a healthy 5-leaflet, hoping that is where the next bud will form. That is how hybrid teas are usually pruned back anyway.

If you aren't sure where the next new bud will form, just wait until you see new growth and then prune back to that new growth.

Kate

Yes it can.

Canker fungi are wound pathogens. Any break in the outer skin (epidermis) - even one not visible to the naked eye - can allow the fungi to enter.

Cankers can be minimized by

(1) Practice good sanitation. Inspect plants frequently. All dead wood and disease infected canes, leaves flowers, buds and hips should be removed when first observed, and discarded with the household trash. Other disease sites can also serve as entry points.

(2) Maintain your roses in vigorous growing condition with good growing practices.

(3) Prune properly in the spring and during the growing season. Disinfect pruning tools by dipping between plants and then do a complete disinfection of all tools at the end of the pruning session. Use the proper disinfectant. If you happen to cut into the canker itself, do a complete disinfection of the pruning tool before you make another cut, even on the same plant. .

(4) Be careful working around your roses so that you avoid accidentally causing even a small wound. Even a small wound that you can't see can be an entry point.

(5) Control other diseases. Other disease sites can also serve as entry points.

The specific control for canker is lime-sulfur as a DORMANT spray. Two dormant applications will clean up the fungi. Personally, I find this material very disagreeable to handle. So we do get some canker every year. YMMV.

This post was edited by nickl on Sat, Jun 29, 13 at 9:17

I repeat, snapping off spent blooms doesn't cause canker--or my rose gardens would have been dead years ago!

I am suggesting that the poster is confusing the little brown "sticks" at the end of the cane (after snapping off a spent bloom) with canker. One must diagnose properly BEFORE hauling out sprays and other treatments for canker--because it might NOT be canker.

But if you truly have canker, then the list covers several things you can do. Myself, if my rose had canker, I'd go down several inches below the canker spot and cut of the cane and dispose of it. There, problem solved. : )

But I still don't think the original poster is actually talking about canker.

Kate

Flower necks (botanically "peduncles") are not normal stem tissue, and they are incapable of producing growth buds. If the flower is removed or does not set a fruit, the plant shuts down the peduncle and kills it off. It will fall off cleanly. Sometimes dying peduncles are infected by botrytis fungi (gray mold), but I've never seen it spread to the stem below. The rose will defend its upper stem tissue but not a useless flower stem with no fruit.

I'm sorry but I must disagree - I have seen stem blight or common canker on stems after improper deadheading.

I interpreted the OP as snapping off somewhere along the stems with her finger, which is what most people do when they deadhead whether they use their finger or a pruning tool. You can deadhead at the peduncle, but most people don't go at it in that way.

In any case, the point is that while canker can be spread by pruning tools, it can also be a result of improper deadheading.

Common canker is usually not as destructive as brown canker but it bad enough. It can spread to other parts of the plant and also to other plants.

This post was edited by nickl on Sat, Jun 29, 13 at 18:10

Interesting responses. Thank you. I do believe I have spread canker by this method because I have a no spray garden. I just keep pruning it out, but some of the sticks will turn black and spread.

I would tend to agree with michaelg, but keep in mind that there's a reason for having a good set of Felcos that can make sharp, clean cuts. Those are much less likely to be susceptible to canker versus pinching the buds off, IMHO.

I have read a few articles that state that canker fungus can enter the wounds caused by crossing canes, improper pruning, even deadheading.

I myself have never seen it happen though...

Please don't confuse a cane stub left by careless pruning with a snapped peduncle. Stubs of normal cane tissue will develop canker. The rose will usually stop it at the junction below, but on rare occasions it will spread down into the healthy stem.

A peduncle stub will always die and often rot, but I've never seen it spread downwards, and I've grown lots of roses over 37 years. There is an abscission layer (a separation joint) at the base of the peduncle that allows the rose to wall it off. In fact the peduncle is dying BECAUSE the rose has already walled it off.

I guess I have snapped off a hundred thousand spent rose flowers with not a single problem.

This post was edited by michaelg on Sun, Jun 30, 13 at 12:30

lainey, a good picture of what you are talking about would probably clear up some of these disagreements rather quickly--if you can supply one.

Myself, I do not call pruning off a cane 6 or 8 or 10 inches down from the end "dead-heading." I call that "pruning." To me, dead-heading is literally snapping off the "head"--the spent bloom--no more and no less.

But obviously some posters have a different definition of dead-heading--so we are in some cases talking about very different things, but using the same words. Result: confusion.

Kate

If I take 8" (or 30") of stem with a spent flower, I call it "deep deadheading." If the rose is too small, I just snap and take no stem. If it is too tall or floppy, I take 1-3 feet of stem. That could also be called "summer pruning," but you would only do it when taking a spent flower off, so it is also deadheading. I think we all understand that, when taking stem off, you should cut just above a leaf. When snapping a peduncle, you don't have to worry about that.

duplicate, sorry.

This post was edited by michaelg on Sun, Jun 30, 13 at 15:07