I have 3 HUGE Rose Carpets (established over 5 yrs.) so I'm very attached to them! 1 1/2 appear to be dying...

Question

losing tons of leaves and more and more are turning yellow. They have black spots and ants...Should I treat it w/ Systemic? Are certain brands better than others or are they all the same? Some exterminator wants to charge about a hundred dollars???

Answer 1

Rose carpets are groundcover roses?

The black spots are a fungus called blackspot... usually not much of a concern except for cosmetic reasons in roses as resistant to blackspot as most groundcover roses. Ants suggest you may have aphid problems. You've had warm, wet weather recently?

I'd consider a soap spray for the aphids, if indeed you have them, and then making sure the plants go into fall nicely watered and pruned, and the area well cleaned up. That's important for both the blackspot and aphid issues. Fertilize and water next year... the presence of blackspot and aphids suggest that the plants have been stressed this year (most groundcover roses are quite resistant to blackspot). Consider a clean mulch
under the plants.

Forget the exterminator. Or was that extortionator?

More help here:
http://www.lakewhatcom.wsu.edu/gardenkit/UnWantedPests/Aphid.htm
http://www.ianrpubs.unl.edu/epublic/pages/publicationD.jsp?publicationId=674
http://www.beginner-gardening.com/blackspot.html

Answer 2

not seeing them it is hard to tell, first mosiac is just that the yellowing is mosiac pattern some green some yellowing, yellowing can be caused by lack of minerals, or to acidic or alkaline soil. try not to water but once a week and only if it hasnt' rained, overwatering can cause yellowing, teh plants don't get enough oxygen if you water too much and die.

try some rose specific food and feed once a week. if you can test the ph that would help. if you can get a ph tester or take it to the country agent, give them a call or test yourself. if soil is too acidic you can add minerals like iron chelate or if too alklalin, then add sulfate compound the garden center would have things to add to soil to make it either acidic or more alkalin depending on what you want. second water from below to avoid hitting the leaves to prevent making the black spot worse.

also prune out weak and spindly branches and branches that cross each other to help with air circulation to decrease moisture stress (with roses it is damp feet (not wet)and dry heads.) when you treat the soil conditons and the plants get stronger they will become better able to resist black spot and handle blackspot treatments but we are entering into winter, you need to build them up as much as you can and be prepared to wrap them in winter, you will have to prune them back for that, if they dont' get better, carpet roses are pretty hardy if they start to improve yee haw!.

your problem is not insects or a virus. I lost my graham thomas it did the same thing turning yellow I did everything but it was a young plant, yours are established and should survive better.

Here is your chance to learn more about roses then you probably cared too, through school of hard knocks.

RRRRR

Answer 3

I am a Certified Master Gardener.

Try the systemic. Water the roses deeply every other day. If there is no improvement in three weeks, then your roses may have a fatal condition known as "MOSAIC VIRUS." There is no cure for MV, and it spreads to other rosebushes.

The diseased roses must be removed, and the area should not be replanted with roses ever again. There is a very high risk of Repeat Planting Virus, in addition to a reinfection with Mosaic Virus.

Don't pay an exterminator. That is a ripoff.

I sincerely hope this helps.

PAMELA J.

Answer 4

I've got those roses, and we had a similar problem. Start using the systemic rose food that's got a pesticide in it for aphids and/or scale - ants usually follow both of these pests. Also, these roses should be cut back pretty good each winter - I'm talking to about half their curent size or more. Once we did that, they came back healthy and beautiful the following spring and flowered all the time as they did in the beginning. I'm not sure where you are, but I'm in CA and these bushes can flower most of the year if well taken care of. Good luck!

Answer 5

get rid of the ants... they're the problem, besides just some black spot.... ants open tunnels which allows air to get to the roots which ain't great for the plant..... they also leave a lot of formic acid around ... again, not good for plants.... do what you have to do to get rid of them... find the main colony by poking around... when you find them exploding out of the ground, you're close!..... get something at Lowes, like Terro, (read the package to be sure what the product will kill, like NOT plants!... Terro's for fire ants, so look for another one!).... once the ants are gone....... prune them back by half... if you're in a cold zone and expecting a chill soon, let it go until spring and then feed with granulated time release 'bloom food'... add a dose of fish emulsion with a half cup of Epsom salts added in a gallon of water......keep the plants watered up until freeze up.....
mine look that way, too... but I have time here in zone 7 for another bloom, so I'm feeding now..... rose mosaic is not a disease of carpet roses... so don't sweat that one.... just get those ants outta there and let the plants recover...... with your help..... they will.....I nearly lost a red maple that they'd set up housekeeping under!!....