Roses - Diseases
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  (May) I have four rose bushes that bloom all summer but never have any leaves. Can you tell me what is wrong?  I have used the systemic method and still no luck. They do get lots of sun.

  I am surprised they can continue to bloom all summer without leaves. Leaves are the source of food production for the plant, and without foliage, usually the plants don't thrive. I am guessing the problem you have is black spot, a common disease of roses, and one that is quite prevalent this year. Black spot is a fungus disease that begins with black spots on the foliage. The spotting on the leaves usually progress to yellowing and then the plants defoliate. This disease rarely kills a plant completely, and they usually leaf back out the next spring, but when the disease occurs, the resulting leafless plant is hideous each summer. If you intend to grow disease-susceptible hybrid tea rose bushes, then plan on spraying weekly throughout the growing season with a fungicide--several will work, including Daconil, Funginex, or Immunox, are just a few. The key is prevention, not curing the problem once it hits. One or two sprays will not do the trick, it must be weekly from the beginning of foliage in the spring, throughout the entire season.

  (June) I just started to grow the roses last year. I was told to remove leaves with black spots or it would kill my roses. I would like to know where the black spots comes from? And how to prevent black spots from appearing on the rose leaves over and over??

  If you have a rose variety that is highly susceptible to black spot disease, handpicking off the damaged leaves is going to leave a leafless stalk. Black spot disease is the most common fungus disease on roses. The leaves begin to develop black spots on them, and eventually the leaf will yellow and fall off as the disease progresses. By mid summer, the plants are often very disfigured. Rarely will this disease kill a plant even in the first two or three years, but it makes them so ugly, that many people pull them up. To combat the disease, weekly sprays are needed from April through September. Fungicides include Daconil, Immunox, and Funginex. IF you are not inclined to spray, consider some of the disease resistant varieties or old fashioned roses.

  (July) I have a climbing Rose that bloomed beautifully, but now the leaves have dark spots on them and are falling off. I am afraid the plant may die. What is my problem and how can I take care of it.

  If you grow a variety of rose that is susceptible to blackspot, don't wait to get the problem before spraying. Blackspot disease should be prevented with a regular spray program, starting when they begin growth in the spring. Some fungicides must be applied every week to ten days, while other products can be used every 3 weeks. Spraying now can help a little, but not a lot. It is unusual for blackspot disease to kill a rose bush in the first season. It can be a problem annually and repeated defoliation will weaken a plant over time. Daconil, Immunox, Funginex or Bayer All in one rose care are recommended products.

  (July) I am concerned about the grotesque growth on two of our roses. I first noticed it last year. The shoots are tender, fast growing, have many more thorns and leaves than normal shoots. They grow out of normal canes, not from the root stock. They can be broken off easily. My questions are; what is it and how do I treat it?

  Your roses are infected with a virus, so you need to cut out the damaged tissue, and sterilize your pruning shears as you cut, so that you don't accidentally cut into clean tissue and spread the infection. The virus causes distorted stems, often extra thorns, misshapen blossoms and more. Beginning stages are often nothing more than some mottled yellow leaves. As it progresses, the stems can get very thick, produce extra thorns and bunches of leaves. If after pruning these bushes produce more of this growth, then dig up the plants and dispose of them. Insects feeding on one plant, can transmit the virus to surrounding plants, so be on the lookout for more symptoms.

  I have a problem with my roses. Already the leaves are turning yellow from the blight which I have fought for a number of years. I recently moved here from Chicago, where I had the same problem. This disease will eventually kill the plant. I have used Daconil already twice this year, plus have fertilized and loosened the soil. I would appreciate any other advice.

  Blackspot disease is a horrible disease, especially on hybrid roses. Daconil is a good means of prevention, and weekly sprays are a must to prevent it. You shouldn’t wait to see the problem before you try to control it. As soon as your plants begin leafing out in the spring, they should be sprayed once a week. This prevents the disease, which is much easier than trying to stop it, once it starts. Two applications is a drop in the bucket as far as preventing the disease. Either spray weekly, or forget about controlling the disease–especially if you have the highly susceptible varieties, which it sounds like you do. If weekly sprays are not possible, consider planting some old fashioned roses which are not as susceptible to the disease.

  Please tell me what is the matter with the enclosed plants and what I can to take care of them. I have a yard full of plants and they are all in real bad shape. Thanks for your help.

  Your rose bush has black spot, a fungus disease that should be prevented with weekly applications of a fungicide, such as Funginex or Daconil. These plants are frequently attacked by the problems you are experiencing. Don’t wait to see the problem, but spray to prevent it. Once established, these insects can be a challenge.

  I have sent you some leaves from our Mediterranean rose and French lilac. We tried everything all summer long to save them. Any suggestions for next spring?

  The rose has black spot, the most common fungal disease we have on roses. They need to be sprayed every week from the time they begin growth in the spring, until they go dormant in the fall. The best fungicides are Funginex and Daconil. The lilac leaf also had a leaf spot, but it is not related to the rose disease. Clean up the fallen leaves around both bushes now and replace the old mulch. Spray with a dormant oil this winter to kill overwintering spores. Don’t wait for the blackspot to occur on the roses next season. Spray with a fungicide when you see new growth next spring. Watch the lilac next spring to see if there are any new spots, and only spray should new spots occur. Fertilize both plants with a complete fertilizer as they begin growing.

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