I have 150+ roses growing in containers. This is the third year for most of them. Suddenly, the canes on a few of them are turning brown (black) and dying. There is no evidence of any disease or pests. I live in Hawaii so there are no weather-related issues. Do roses sometimes die for seemingly no reason at all?

I am certainly NOT a rose expert, however, canes turning black sounds like too much water / root rot. I lived in Hawaii for a while and depending on location it can be wet pretty much 24/7.

Maybe pull one out and take a look at the roots?

If canes are turning black, check for canker. It is a fungal disease. I even get it here in my dry climate. Make sure when pruning or cutting your roses, you wipe the blades with an alcohol wipe. Do not use one with bleach. The bleach can ruin the blades on your pruners. The alcohol wipes will ensure that you do not pass the disease from one rose to another. https://www.rose.org/single-po...

kohala said: Do roses sometimes die for seemingly no reason at all?

Not in my experience.

In fact, those roses with which I have experience that have suffered sudden death all had one thing in common: me as their gardener.

Yes, mine die of the same affliction here.

LOVE that, LOL!!!

OK, add me to that list! Total neglect has killed most of the roses I planted 20 years ago in my garden. Now I am 70 years old and trying to rebuild my garden. Hope I live long enough to enjoy my efforts. I didn't have to think that way 20 years ago. Add to that I am now experimenting with own root roses and you add 3 years from planting until there is a substantial bloom cycle.

JBarstool said:

Not in my experience.

In fact, those roses with which I have experience that have suffered sudden death all had one thing in common: me as their gardener.

Maybe you're right . . .But I don't know. All my 150+ roses are grown in identical conditions. All are grown in containers, in the same soil mix, fertilized the same way and get essentially the same amount of sunlight. I have no problem acknowledging "operator error." But why did I only lose two?

Did they come from the same nursery?

No. One was South Africa, which I purchased from Ace. The other, Lava Flow, was purchased from an internet nursery,I cannot remember which. Both were vigorous growers, with beautiful blooms. Both were pruned about six weeks ago as were all the others.

Kohala, Yes they do. I grow >200 roses in big pots very successfully. Several years ago, I had several roses die for no reason. A couple of years later, I noticed crown gall on several others. My gut feeling is that the bacterium for crown gall got imported from some vendor, (too late to know now who it came from) and because I'm kinda lax about hygiene when it comes to re-potting and weeding by hand, I spread it. I still have several roses with crown gall growing well, and I'm now super careful about not weeding them and moving on to another bush. I also think that sometimes roses just die for no reason, or reasons I don't know. I have a mix of own-roots and grafted. It's not over-watering.

Another possible reason is that the roses may need repotting. I try to repot my container roses with mostly new soil every three or four years. I just repotted one today which was partly dying, but I realized I hadn't repotted it in five years.

Should you wish to repot them, that would also be a good time to shake off all the loose soil to look for root rot and crown gall. If a rose has crown gall, just toss it.

Last season I witnessed something of that kind. I read carefully the various posts but I would like to direct towards @MustbNuts proposal. I did get an unexpected canker attack two weeks just after a spring freeze which killed new shoots. The canker took a huge toll of many of bushes afterwards and yes the browned or blackened canes with dead new growth. My only option was to prune the diseased plants as hard as possible. I did loose about 10 bushes anyway. But what really fooled me was that some didn't wither and die immediately. They bloomed nicely and two or three months later towards mid summer a few of them went downhill and gave up their ghost! ( i.e 'Christopher Columbus'; 'Just Joey') These following I lost progressively during the season: 'Georgette' -Interplant; 'Pink La Sevillana';'Loving Memory' ; 'Madame Plantier'( o.r.); 'Gloire de Mousseau';'Comte de Chambord'; 'President de Sèze; 'Souvenir de la Malmaison Clg.o.r)) none of these , I could find a replacement in spite of searching like a detective Today looking how my bare canes are faring after the by gone snow I discovered my 'Fourth of July' with healthy green canes and clearly brown parts that I'll prune as suggested . I thought that one was a goner... , because I haven't found a replacement or duplicate yet. Because for many of the goners finding a source of replacement is a major feat... , this season I expanded my collection with a lot of duplicates so that I have at least backups in case of this unexpected disease reappears. This years' purchases always start with two of the same kind if they are unusual varieties.
Canker or some of its fungi involved seem to have a delayed expression. But also the immune system of the roses seems to act someway. Otherwise I would have lost all them in one go. Other than strict pruning hygiene, canker doesn't have a specific treatment so I find myself quite defenseless. I still am ready to jump into the something that I may have done wrong wagon because like roses diseases also are causes of unexpected (unpleasant) surprises too.

Arturo

Arturo...do you root cuttings from the rare ones too as a back up?

Dennis...I am dealing with browning canes on my Double Delight...it was next in line to root cuttings from...I think I'll move that one up. How were the leaves looking and were there any blooms? I tend to have things stall, not grow and then up and die, but Double Delight just had canes die, one by one. Also, my South Africa is own root and very vigorous...if you get another one, I am betting you could root a back-up pretty easy.

@Sandsock

Annie all my root cutting trials have failed up to now. From what I've read, I should use IBA (indolbutyric acid) rooting hormone which is very difficult to buy here in small quantities. I also read that ideally they should be placed over a warm matt with intermittent water spraying. Well in my given present facilities it is a project coming up soon, but still on the wait line. I'm also trying to graft onto rootstock. Again that I've failed too, I'm not sure why, since I followed instructions carefully ( ). Meanwhile, I try to purchase replacements/ backups so that I can buy time whilst I acquire those abilities. However I haven't given up hope in both alternatives.

Arturo