Once the leaves have spots, they are doomed. You can leave them on (they will eventually fall off) or pick them off. The rose can be weakened by not having leaves on it, but it should put out new ones.

There are several fungicides you can use, but most of them require preventive use before the black spots appear.

You don't say where you live and that could make a difference. But basically you can remove any yellow leaves but leave anything that's still green. As long as the leaf is green it's still continuing to produce food for the plant even with the spots on it but they will eventually yellow. Once it's yellowed it's no longer producing and can be removed. The choice to use a fungicide is up to you. Like Buford said, they work better as a preventive than a cure. Black spot is rarely fatal to a rose. It could kill a rose that is already stressed from something else though. Also if you are going into winter it's a good idea to get the roses as healthy as possible to get through.

Ants do not cause yellowing leaves but may be feeding on the residue left by aphids which do cause some damage. Look for very small green or white insects at the tips of new grow and buds. You can just take your fingers and wipe them off if you find them.

ignore it, I am afraid.

I find that Bayer Advanced Garden Disease Control for Roses, Flowers, and Shrubs is a very effective fungicide. I rarely spray with it, but if there is a BS attack (usually in the spring and fall), I spray with it a couple times and that usually solves the problem. However, that is because our summers are so HOT that BS cannot survive the heat--so little BS problems in the summertime. It is also dependent on regularly monitoring my roses for BS so that at the first sign of it, I rush out and spray the Bayer fungicide and a week or 10 days later give the roses a second spray. If you wait until your rose has a really bad case of BS, I'd guess it takes quite a while to get things under control again for those roses.

I agree with what the other posters said about yellow leaves, but you did not say spotted yellow leaves. If you have lots of yellow leaves but no spots on them, consider the possibility that you are giving your roses too much water--that will cause yellow leaves. Just another possibility as you are diagnosing the problem.

Another thing to consider. If it is toward the end of the growing season, some of those problems you describe just might be old leaves --dying of old age. Not much you can do about that. Good news is that the bush will produce new leaves to replace them.

Kate

A humble opinion: I don't think that blackspot weakens roses; I do nothing to try to stop blackspot, just ignore it.

If leaves fall on the ground, I rake them into the ground to recycle them.

Leaves are a vital piece of a rose plant. They convert sunlight to food through photosynthesis. I worry about leaf loss not only because the shrub looks shabby, but because it's like the loss of an organ. Nothing functions optimally when it's missing a key piece.

The good thing is that a rose can replace its leaves, and like Krista says, sometimes it can be ignored if it's not too severe. My Folklore went totally nekked this summer and stopped producing blooms. I treated it with fungicide a couple of times and cleaned up the infected leaves, and it bounced back with new leaves and blooms.

It really depends on your tolerance for disease, leaf loss, bloom production, and how quickly you notice it spreading. I use the Bayer spray that Kate uses, and I spray maybe 5 times a year.

I changed my practices this year to spray once, early, before letting BS get a foothold, and results were much better than spraying as a reaction to already visible BS.

If I recall correctly, Jimmy, you live in Australia, don't you? It should be spring/summer there now, right? If that's the case, your rose is susceptible to the fungus. Here, it's late in the year and diseases are pretty much to be expected due to the weather and fact the foliage is "old" and ready to be shed for the winter. Earlier in the year, black spot could simply be weather pattern related and might clear up if removed and perhaps sprayed. If it doesn't, then that rose isn't suited to where and how you grow it. A different choice, one with better black spot resistance, might be a better alternative.

The ants don't cause the foliage to yellow nor fall. Ants don't eat roses, but they do eat the "honey dew" left behind by quite a few sucking insects. Aphids, scale, mealy bug can all produce the honey dew, sugar water, and the ants eat that. Sucking insects, if in a bad enough infestation, can suck out enough sap from the plant to weaken its immune system and make it more likely to contract fungal diseases. Think of yourself, if you had bleeding issues, over time, the loss of blood would weaken you to the point of being more susceptible to contracting some disease because your system is weakened. Taking care of the insects which are sucking your rose's sap, cleaning up the infected leaves by removing them from the plant and raking the fallen ones from around the plant, determine if you want to spray fungicide or not, feed and water the plant to encourage it to grow and flower appropriately for your season and watch to see how it performs. If it still contracts black spot, either move it to some other location where air circulation is better, humidity is lower, fun exposure is greater so the foliage will be drier and warmer and see if that helps. If it doesn't, you should consider changing that rose for something else more resistant to black spot. Kim

Humor time.....from the anal-retentive nightmare....

Kim, best typ-o EVER. I am absolutely LOVING the idea of 'fun exposure'. I need to be moved to a location with more fun exposure!!

Thanks flaurabunda! Sorry I missed that one, I'm glad it amused you! Didn't the contraction of "full" and "sun" make sense to you? hehehe Kim

Ah, so it was a contraction!

I compile & proofread our SEC filings for a living. Nature of this beast, I suppose. Speaking of work, I tried to convince my boss that I need to move my desk to a place with more fun exposure, but she didn't go for it.

Well, not a deliberate contraction, one of the "brain fart" kinds. Your boss sounds like a stick in the mud...much like a black spot defoliated rose bush! Kim

I like "fun exposure" too! I try to find something fun to do all the time!

Knowing that you're in Australia makes a difference indeed. Our springs can be very wet and warm and that's a major aid in the growth of black spot. So if those are your weather conditions right now then that could be the cause. Try some spray but now you're playing catch up and will have to spray regularly to keep it at bay.

I agree, Krista, black spot on it's own is not fatal. But a rose that is already heavily stressed from something else or badly infected going into winter and unable to store adequate reserves of food from leaf loss could die.

You can put up with naked roses.
OR you can plant better disease resistant roses for your area.
OR you can spray with fungicides...
The choice is up to you...

ooops forgot to finish...lol
Ants are not turning your rose leaves yellow.
I personally do not clean up disease infected roses off the ground nor on the bush.
If a rose gets to much BS or other fungus diseases here and it loses a lot of leaves I replace the rose with a better one.

I'm in the "ignore it" camp. I tried picking up leaves, spraying fungicides and you just can't win without cooperation with the weather.

I only select DR shrub roses now and plant them far apart with lots of sun.

Some years ago, our Jeri and her great husband, Clay, spoke at a Huntington Old Rose Symposium about ridding your garden from diseases. As Jeri stated, "You CAN rid your garden from diseases!", all eyes were front and center, many on the edges of their seats. Clay held a shovel over his head and shook it like a weapon and the crowd exploded! Wonderful experience and funny as they come! They're right, though. Selection of the best rose for the best place, often difficult and requiring a lot of research, exploration and education, is the prime way to eliminate disease issues. Nothing will ever be perfect, but if avoiding the costs, dangers and work of having to use chemicals is important enough to you, it's the ONLY way other than to grow anything else which isn't affected by the plagues. Kim

My two climbing roses (altissimo) have blackspot for the first time this year. The roses are about 7 or 8 years old. I live in Constra Costa County, east of San Francisco, and it's hot and dry here in the summer and relatively cold (it can freeze) in the winter. Do I ignore the blackspot for now and wait until February when I prune them, or is there something I should do now? If so, what? thanks!

Get some Bayer Advanced Garden Disease Control for Roses, Flowers, and Shrubs. It is an effective fungicide. Spray your BS roses twice, about a week apart. Hopefully that will stop it from spreading. If not, spray a 3rd time about 2 weeks after that (and every 2 weeks thereafter if it keeps on spreading).

Note that you cannot "cure" leaves that already have BS. You just want to stop it from getting worse. The BS leaves will eventually fall off on their own, so you don't need to bother with them if you have stopped the spread of BS with your fungicide.

I buy it at Lowes. The other places--Home Depot, Wal-mart, etc.--don't carry it for some reason. I imagine you can also get it online.

Kate

I remove them from my yard.

Minor bits of blackspot don't bother me too much if the bush keeps most of it's leaves and bounces back quickly....many (but not all) old garden roses stay very happy and beautiful with minimal blackspot, if the correct ones for an individual's climate is selected.

Blackspotty roses that are naked a good deal of time despite having good fun exposure are asked to leave:)

Sandy

heckabore, if you only get bs very occasionally, you can ignore it. If you do get a dormant period, you can spray your roses with lime sulphur during that time (as long as temps are above freezing) this will kill any overwintering spores. Sometimes if you let bs carryover on the rose in the winter, when they leaf out in the spring, they will get it right away.

I've only been growing roses for three years, in the first year I sprayed, the second I didn't, and this year I'm thinking I'll go ahead and get rid of all my disease prone roses. I still don't have much practice with shovel pruning but I've been seriously eying Midas Touch and Chris Evert, the flowers are so beautiful but the bushes are so ugly!

Garden sprays exited our garden when our dog began to seizure every time they were used.
Even if we hadn't cared about the dog, it seemed obvious to us that anything which triggered seizures in a dog couldn't be good for us, either.

Blackspot is a very rare problem here. The only rose that ever defoliated all over because of it was removed instantly.
Our problems, for the most part, are powdery mildew and rust. Anything that reaches maturity here, and remains susceptible to those problems is removed.

There are thousands of roses that don't need chemical sprays to flourish, so the choice, for us, is very simple. Very clear.

Jeri in Coastal Ventura County,
Southern California

Jeri

After spraying several rounds and I still have BS, I either strip the leaves or cut back. If BS continues over the years, I re-evaluate if the bush is worth the trouble. If it is, I may move it to a more open area and if it isn't, it gets shovel pruned! This can reduce BS problems for the other rose bushes, too.