Black Spot on Rose Leaves

Black spot on my new roses. Do I need to do anything? Are these diseased leaves?

The first picture might be something as simple as a bit of sun burn, but could also be the beginnings of a disease. Turn the leaves over. Is the discoloration worse on the back?
I am also concerned about the end of the branch that ought to be growing.

The black netted effect is definitely a problem. I would remove this leaf, and any other showing it.

Thanks Diana. On the first picture, the discoloration is only on the surface, nothing on the back. The roses only receive morning sun until about 1pm. Too much sun? Too little sun? I wish they could tell me :)

I'd removed any leaves that have black spots, some just fell off upon touching so they must have been sick.

Should I spray with anything? These are new rooted cuttings.

This message was edited Apr 13, 2015 7:17 AM

Too much sun, but only from this point of view:
New cuttings have no roots, greatly reduced resources for gathering water.
We have had a mini-heat wave recently, which might have been just enough to burn the leaves of new cuttings.

It is going to get warm again by the end of the week, perhaps rig up a little bit of shade or move the pots so they do not get sun after about 11AM? Filtering the light is good, or bright shade is good.

I would not know what to spray with. The black netting/webbing looks familiar, but I do not know what it is. Was it on the leaf surface, something that would brush off? Or was it inside the leaf?

Inside the leaves, looks pretty bad although only on a few leaves. I'll move them to bright shade and hopefully that helps. Thanks Diana.

If it's something that is INSIDE the leaf, (That is it's between the flesh of the leaf) rather like you have a splinter and it's just under the top layer of skin, then remove the leaf, use a needle or pin to try separate the layers of leaf to allow you to examine the vacant space between the layers of the leaf.

There's every possibility that a little bug will be there, it's called a leaf minor, and is quite a problem on certain plants, IF there are no Bugs, then you have a disease that is affecting the cuttings.
I also am concerned for the little brown growing tip on the one plant as it looks as if it has Die back, quite a common problem on Hard Wood cuttings,
My preferred way of trying to root Hard Wood Cuttings is to place them as close as possible towards the outer edge of the pots, this does 2 things that cuttings like for root formation, 1, the soil at the outer edges dries faster therefore the cuttings are NOT sitting in wet soil for too long, 2, the outer edge of the pot gets warmer, this little extra heat encourages the cuttings to make roots faster.

Once you know the cuttings have made roots and they are growing well, (how long this takes is dependant on the type of plant your rooting) to check for roots, after several weeks / months, give a cutting a gentle tug and IF there is a slight resistance to come free from the compost / soil, then you can assume roots are formed. I personally would leave the cuttings be till you feel the pot is full of roots,
Once you have reached this stage, empty the cuttings and soil out from the pot, gently tug the rooted cuttings apart without loosing / breaking roots, and pot the cutting up into individual pots taking care NOT to use pots that are too large, IF too large pots are used, it means the cuttings are sitting in far too much soil, getting too much water and will lead to more problems such as your experiencing now.
Hope this helps a little and you get all the cutting you want as it's a great way to expand the most favoured plants you wish to increase.

Good luck and kindest Regards.
WeeNel.

Thanks WeeNel. Great tips! :)

Hi, my band size roses are growing nicely, but I'm getting tired of watering the pots daily especially the weather is so hot and dry now. If I plant them in the ground and dig them up in 1 year when I move, would that damage the roses?

If you can dig them when they are dormant, they should be OK.
Could you move the containers to a slightly cooler location when the hot sun comes around?
Or shade the containers so the sun does not cook the roots?

I would think these cuttings will be better planted outside in LIGHT shade and cared for there, IF they have roots, they should be fine, just make sure they are not allowed to dry out and you remove AND burn any deceased leaves as you dont want bugs / deceases to keep spreading.

When you are ready to move house, you should prepare the cuttings earlier, that is to get some good compost, larger pot, fill the pot and plant each cutting, allow the plants to get used to the new environment in the pot, set out in LIGHT shade. you do this about 2 weeks before you move home. Once you have settled into new place, dig the holes for the plans and add some ROSE fertiliser to the soil, nice compost as before, mix in the Fertiliser, (Only use the dosage recommended on packet ) too much feed can kill the plants.
Hope this all helps you out and the cuttings survive there move, you will have much pleasure from them for many years to come.
Kindest Regards. WeeNel.

Diana when do roses go dormant in California? My established red rose seemed to be very happy in the winter and put out tons of new growth and blooms. It was heavily pruned in October. (I asked my gardener to do a yard clean up. Didn't know better when to do what.)

WeeNel's recommendation is to take new cuttings and not to disturb the planted rose? I would definitely try to make more cuttings when my roses are big enough.

I'm keeping some in bigger pots and planted a few today. It was a lovely cloudy day. Thank you both for the advice. :)

Some roses stay evergreen, especially in the milder parts of the bay area, and especially some of the newer varieties. Also, if the plant is near a south or west wall where the sun's warmth makes the winter a little milder, this can also keep them evergreen.
If they need to be cleaned up and sprayed while dormant, then I would pull off all the remaining leaves in January, do the pruning and dormant spraying then. The weather often moderates by February, and this will trigger new growth.

If the plant is doing well, and does not need quite so thorough a clean up, then don't bother trying to enforce dormancy.

October might have been a bit early, still mild enough that the pruning encouraged new growth that could have been hit by frost. Just a little risky. Most years you are mild enough that there is no frost cold enough to be a problem.

Hello, I have another question regarding transplanting band size roses. I put a healthy band size rose (been growing in the pots for 2 months) in the same spot where I had a 10-yr old Euonymus shrub removed. The soil is fluffy and I'd been watering it every day for the last week. I notice the rose's leaves are curled and feel kinda crisp (they're still green). Could it be rose sickness from the old soil??? :(

Could the summer heat cause rose leaves to curl up? I'll post a photo tomorrow.

Curled and crisp, but still green suggests it suffered once from a sudden dry/heat episode, rather than a long term marginal conditions.
The way the weather has been up and down lately, it sure could have experienced this sort of problem.

Don't worry about the leaves, as long as the stems and buds are OK.
If the stems have dried out you can cut them back to a good, healthy spot.

Watch the weather reports and set up some shade for the hot days.

Thanks Diana. Here's my newly planted Marie Pavie. It was very healthy when planted now looking sad.. I put a laundry basket over it to cast some shade, hopefully that'll do.

I think I am seeing a couple of issues with this rose.
The red and white arrows point to powdery mildew.
The blue and yellow arrows point to something else.
I do not see dried or sunburned leaves on this plant.

Ok... could it be the old soil from the shrub? What should I do to revive it? Move it to a new spot or pot it up with fresh potting soil?

You could try something as simple as watering it slowly for a long time. This would flush out salts and a few other things from the root zone, if that is where the problem is. I don't know.

I moved it to a new spot. Thanks. :)

The same rose is doing much better at the new spot, the leaves are no longer curled (thank god). There are however some yellowing on the leaves. Any advice?

The second picture is a different rose own root Lemon Spice. What are the white stains on the lower leaves? Looks like the slugs / snails have been munching on them since I water at night.

Thank you rose experts for your help!

Overall these look pretty good.
I would not worry about an odd looking leaf at this time of the year. Just pull them off, if you want to.
They plants should be going dormant soon, (if they will at all) and old, tired leaves are to be expected.

However, looking at a list of rose diseases and pests in this area might show you what to watch out for next spring.
Most common diseases in S. F. Bay Area:
Powdery Mildew
Black Spot
Rust
Mosaic (a virus- cannot do anything about it)

Most common pests in S. F. Bay Area:
Aphids
Leaf Miners
Spider Mites
Curculios

Most common cultural problem:
Too wet or too dry soil. Many areas have a clay soil that does not breathe well. It gets water logged easily and excludes oxygen, or else it dries out and is hard to get it to accept water again.
Salts in the water: Fertilizers, and (depending on the water system) actual salt from the bay that is making its way upriver at low tide to the intake (Contra Costa Water District occasionally has this problem, and some wells near the bay are being infiltrated by salt water). Some plants do not like fluoride in the water (Aglaonema is one example). If you are watering with grey water the laundry detergent MIGHT cause problems- It does not, in my garden. I think the rinse cycle provides enough water to properly dilute the detergent.

http://www.ipm.ucdavis.edu/PMG/GARDEN/PLANTS/rose.html

Thank you Diana! It is hard not to obsess over them because they're my first roses.

I'll do more research on the disease and pests you listed, and grab a few garden books from the library to learn more.