Looks like powdery mildew. You can try spraying the foliage with the hose. Unlike most fungi, PM thrives in dry weather. Rain washes the spores off of the leaves.

I usually deal with white flies and aphids with systemic fertilizer. I've got a little PM and the discolored leaves look like the rose slugs I had last year.

I would say.
1 - virus. Not curable, but not spread able.
2 - spray aphids off with a hose. They don't climb back on. If that fails I do like taking a soapy rag and wiping the plant rather than spraying.
2b - powdery mildew. Spray the leaves down every morning.
It stops out from spreading. Remove infected foliage and keep up the routine.

3 - not sure. Could be many things.. I get signs like that with too much fertiliser.
The New growth is weak and prone to infection and disease.

As for rust. I do not know what to do. Rust is very uncommon here and it tends to be solved by watering less.

I would say.
1 - virus. Not curable, but not spread able.
2 - spray aphids off with a hose. They don't climb back on. If that fails I do like taking a soapy rag and wiping the plant rather than spraying. Ladybugs will just fly away immediately if released at the wrong time.
Let them go at night. They tend to stay.
2b - powdery mildew. Spray the leaves down every morning.
It stops out from spreading. Remove infected foliage and keep up the routine.

3 - not sure. Could be many things.. I get signs like that with too much fertiliser.
The New growth is weak and prone to infection and disease.

As for rust. I do not know what to do. Rust is very uncommon here and it tends to be solved by watering less.

This post was edited by Ordphien on Thu, Apr 10, 14 at 22:09

The aphid spread rose virus is supposed to be widespread in California,

Here is a link that might be useful: link for above

Henry, did you check out the photos for the Rose Spring Dwarf virus your link is referring too? Looks very different from the leaves shown above. Very Different

#1Nothing you can do about it except pull off the leaves if they bug you. Chances are you will only see those in the spring and the rest of the leaves will be fine.

#2/#3 Mildew

Abe Darby, Don Juan and Peace all have a touch of rust on the older leaves but look okay on the newer ones.

To be clear on #1: it is a disease, commonly called "rose mosaic virus." It came with your rose. Many roses grafted on Dr. Huey rootstock have been infected with the virus over many decades. There is no cure. It can weaken a rose, but in many cases, it just looks bad, and the rose can live for many years. I have a few in my yard, I only see the symptoms in certain years.

The powdery mildew in 2a is usually weather related, and clears up in hotter weather, although there are some varieties that are more susceptible to PM than others.

Can't help with the rust, we don't see it much in these parts.

My virus. On SDLM .
Came out after 4 years dormant. See it mostly in first flush of leaves.
I hate PM. Use sulphur or soap or potassium.

Kippy-the-Hippy, it would be very helpful if some southern California rose growers who have personal experience with the variability that rose spring dwarf can exhibit with different types of roses (including roses with more than one type of virus infection) would write an article on the subject. I feel that it is too early to make positive identifications based on leaf characteristics alone.

Just know that we all deal with these issues, maybe not all at once, but I once posted a thread about all the problems I had with my roses in spring.

I don't think the mosaic virus is so bad with California roses. I have it with my Eye Paint climber. Sometimes, I just cut those branches off. However, I got rid of a virused Altissimo years ago and replaced it with a clean one.

I grow alot of roses and when I was working, I felt I didn't have time to wash off aphids, as it needs to be done more than once. Now that I am retired, I do hose off aphids. In doing this, I have found that each year I have less and less aphids. But if you want to grow roses, you WILL have aphids. I used to use poisons once or twice in spring but not now.

Powdery mildew is a fact of life in my garden. It goes away when the nights and days are warmer-- but I have a couple of roses that look awful right now. I can't fight it, so I don't sweat it anymore.

Rust? I will not grow a rose that has regular rust problems. I got rid of a wonderfully growing Abraham Darby on a trellis as it always got rust. I just won't deal with it.

I guess over the years, I have learned to live with the frustrations of rose growing and not get all upset like I used to. Roses are very hardy and they survive all the miseries they entail. I try to just enjoy them as much as I can.

I agree with Kathy. Keep your roses well fed, well watered, and well mulched (tend them in ways that encourage them to develop deep root systems) and then don't worry about moderate disease and pests. If a rose shows itself to be a poor grower or particularly susceptible to disease, get rid of it. Give your roses time to mature. If you avoid pesticides you'll get beneficial insects, also insect-eating birds. By the way, ladybugs are more likely to hang around if they have a bit of plant litter as a refuge: a few weeds and a bit of tall grass, some dead plant growth. Stringent tidiness is unfriendly to them.
Melissa

That is not rose mosaic virus. Some roses here in SoCal get whatever it is on usually just a few leaves in the spring but the rose is not weakened and it goes away. It is like variegating and I think it has something to do with the fact that they are growing so fast in extreme heat and dry conditions. The other is powdery mildew which I have learned to deal with. You must spray them with water and they must have ventilation and especially the morning wetness must dry. Some roses that are prone to PM will get it bad if they are shaded from morning sun. My McCartney was covered with it last year when it didn't get morning sun and now in full sun there is no PM. Rust is caused by dryness and general stress. I had it on roses that for one reason or another weren't watered properly and were stressed but never on properly cared for roses.

As has been stated, your yellowing is viral. There is nothing to do to "correct" it other than to replace the plant with one which is (hopefully) not virused.

Aphids love greenhouse conditions...humid, warm. Once it dries and heats up, they move on, presuming it gets hotter and drier where you are. Spraying with anything other than plain old water could easily burn the foliage with the heat which should be starting soon.

Mildew and rust can be induced by keeping the plants too dry. Drip irrigation might not be sufficient, you may want to increase the water to see if it helps. Some roses will mildew and/or rust no matter what as they are just susceptible to it. It is entirely possible to force many to rust and mildew by keeping them too dry. I experience it with potted seedlings frequently. I tried growing R. Arkansana in a pot here, but had to water it daily or it rusted horribly. My potted Cal Poly minis will rust awfully if I allow them to dry out. Try increasing your water and see if that helps. If it doesn't, you may want to investigate systemic fungicide/insecticide. There is nothing "organic" to substitute.

There is a trick to releasing lady bugs in your garden. First, water everything well, including overhead so the plants are wet. The lady bugs will be thirsty when first released. Second, release them at dusk. They don't fly at night, but will remain in place, eating what they find, until it's too dark. Third, don't release the entire batch at once. Only release a third to half of them one day, put them back in the refrigerator for a day or two, then release more. Lastly, shake them off at ground level. They will naturally climb up to the tops of the plants, looking for food as they climb.

By making sure there is available water; releasing only a small portion of the available lady bugs per release; shaking them off at the bases of the plants; and releasing them at dusk, your chances of more of them hanging around a little while to eat some of your aphids (and lay eggs as they feed) are greater. Remember, though, they will not eliminate all the aphids on your roses. Humans are the only predators in Nature which eliminates its food source. All others leave some to repopulate, to produce more food for them. If you have to be completely aphid free, pesticides are the only "cure". If you choose that route, don't waste your money on any predatory insects as they are most often more susceptible to pesticides than the "pests" are. Kim

I have that yellowing on a quarter of my HT"s and they can't all have rose mosaic. And it doesn't look like rose mosaic which I know only too well. What I have I attribute it to stress brought on by insufficient nutrition and/or water, poor soil and very dry conditions occurring during extreme growth. It also occurs sporadically on the bush. Some things about rose mosaic virus. Rose mosaic will occur on infected roses most prevalently on the older canes and may not be on the newer canes which are often entirely free of it. If it is on a cane the entire cane will be infected and once spotted the entire cane should be removed. I found that removing old canes was a means to keep it at bay and rarely did it appear on new canes and never sporadically.

SoCal, have u tried baldo Villegas pages of rose conditions.? It
is very helpful.
Just google him.

This post was edited by susan4952 on Fri, Apr 11, 14 at 21:18

I agree with the ideas already offered and add that planting society garlic around my roses helped drive off aphids. Also, ants will keep aphid predators away and move aphids around. If you get rid of ants, the aphids are less numerous. Rust seems to have been brought on by the rainy days and virus markings by the warm days.

I miss the good old days of wet winters and dry springs in So. CA

A lot of my roses have mildew right now. It usually clears up when it gets hotter and all I do is spray the roses with water. I don't have the yellowing of the leaves although the old leaves from last year do look yellow or partially yellow, but not in the way shown on your picture.

I hate rust and fortunately don't have too much of it. If a certain rose keeps getting it I get rid of the rose. I grow mostly old roses, and a lot of tea roses (not hybrid teas) and they don't seem to have much of a problem with rust.

Ingrid

To me, the yellow looks exactly like rose mosaic virus. And yes, lots of roses can exhibit it, especially if they are grafted hybrid teas. In fact, I seen comments more than once on this forum that most of the rootstock in the US has been infected--which means that most of the grafted roses we buy have it--unless the nursery has taken special measures (expensive!) to get rid it. And most of the nurseries have NOT done that.

The good news is that usually the symptoms of rose mosaic virus just appear for a short time (spring seems to be a popular time) and then they go into hiding. I have an Earth Song--about 6-7 years old--that every once in a while exhibits leaf symptoms. Rest of the year--it looks and blooms just like any other rose would. So I don't worry about it, and if a leaf with symptoms gets on my nerves, I simply remove it so that I don't have to look at it.

Here is my rmv Earth Song--bright pink, and blooming well, in my opinion.
{{gwi:259578}}

Kate

This post was edited by dublinbay on Sat, Apr 12, 14 at 12:29

Often when the subject of rose viruses comes up, there are comments from growers with hot summers that an infected rose is not a big deal. The early research appears contradictory on this point, The following link is to more recent research in Poland.

http://www.up.poznan.pl/ptfit/pdf/PP44a/PP_44_027-035.pdf

In their introduction they appear to recognize that higher temperatures reduce the effect of infection:

"On the other hand, Wong and Horst (1988) have not observed any effect of viral infection on stem length and total number of rose cut flowers among âÂÂBridal PinkâÂÂ, âÂÂFragrant CloudâÂÂ, âÂÂGrand MasterpieceâÂÂ,
âÂÂSamanthaâ and âÂÂSimplicityâ cultivars. The plants were grown in greenhouse, and the elevated temperatures may have alleviated effect of PNRSV."

The Polish research is consistent with the theory that roses have an immune system against PNRSV that is more effective at higher temperatures.
http://home.roadrunner.com/~kuska/high_temperature_effect_on_pnrsv.htm

Here is a link that might be useful: Polish rose virus research