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Shasta Daisy-browning, die back
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Date Posted: Tue, Aug 17 - 8:52 pm
- I have a large shasta daisy that I planted along my side yard years ago. About 3 years ago it started having "issues". It starts the spring with very green and abundant stems/leaves. And everything seems wonderful as the plant starts to bud....but then the flowers bloom already browning and die quickly. I am guessing it has some kind of wilt but not sure what to do. I also have dianthus in pots up my steps for the first time and it appeared that they also caught "the wilt" but they seem to be bouncing back. Not so for my Shasta daisies. Is there anything I can spray them with or can I transplant? It's such a gorgeous prolific plant.
- Sorry to hear of your daisy troubles. I'm going to refer to a previous answer I gave about Rudbeckia 'Goldsturm'. The daisies are also one of the stalwarts of the garden but can run into various problems. Please see the rudbeckia answer below. I didn't spell it out in the answer below but good drainage and air circulation are essential for plant growth and prevention of fungal diseases. And again, if your plants continue to succumb, selection of a new plant for your particular environment may be a good solution. Good luck, let us know your progress! "Rudbeckias are usually pretty sturdy plants but they do succumb to some fungal issues. Sometimes the problem could be attributed to too much water, so that's a simple fix. Or, you may be dealing with septoria leaf spot or a similar fungus. Rain and humidity contribute to the problem. You can start with some cultural practices. Remove all affected leaves and put them in the trash. The fungus overwinters in infected plant debris so you want to clean up the area around the plants to make them less inviting to the fungus. You may also try moving the plants to a spot with new soil and seeing if the plants improve over time. Additionally, do not water from overhead. Try a soaker hose so that the foliage does not get wet. You could also try a baking soda solution spray but that's usually better at prevention. A neem oil solution may be effective. You may decide to simply remove them from the garden and substitute another perennial that's less susceptible. There are many choices. A lot of gardening is just adapting to your circumstances and trying new plants that may be better suited to your patch of ground. Best of luck with your garden! "
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Japanese Holly Dieback
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Date Posted: Tue, Aug 17 - 8:37 pm
- There is a hedge at the front of my property. Someone years ago told me they are Japanese hollies. I found a tag on a bush in the back yard which I believe is the same plant--it's Ilex crenata 'Bennett's Compacta'. They had been very healthy and growing almost too well for nearly 12 years until this spring when one bush turned brown in a matter of days. I cut out all the brown and there is some new growth near the base, but I have 2 questions; 1. What are likely causes of the die-back? 2. What are the chances that this will affect the other bushes? Since it's the front of the property it's already unsightly--looks like a missing tooth--but I don't want to replace the one diseased bush in the row if they could all be in jeopardy. Thanks for your help. Shelley
- Hello there, Without seeing the plant and the place it's situated, my best guess about the origin of the dieback is black root rot. I am attaching a link here from Virginia Tech with an information sheet. It's a tough problem. If you believe that's why your shrub succumbed and since the hedge has served you well for 12 years, it may be time to replace it. Of course, any replacement would have to be a variety that will not be susceptible to this root rot. Let us know if you have further questions. Best of luck.
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Boxwood with patches of brown leaves
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Date Posted: Tue, Aug 17 - 8:35 pm
- I just bought a house and I have a boxwood bush in the front that has patches of brown leaves. Is this that blight that I've heard people talking about? would it be a good idea to remove the bush or is there something I can do?
- Thanks for your question. This does sound like it could potentially be boxwood blight which is a fungal disease, and for which there is no cure. This disease first appears as lesions with dark brown edges on the leaves and black streaking on the stems. The foliage then turns brown and falls off. Observe the leaves and stems on your boxwood for these signs. If your plant is minimally affected, you can cut off affected branches, clean up debris from the ground, bag the trimmings, and put in the trash (do not compost). You may then be able to keep the disease at bay by spraying a chlorothalonil-containing fungicide every 7-14 days. Be sure and sanitize your garden tools with a 1:9 bleach to water solution to avoid spreading the disease. If your boxwood is heavily infected and unsightly, it may be easiest and safest in the long run to remove the whole plant. It’s also important to know that the spores from the infected plant can remain in the soil for 5-6 years, so if you want a replacement plant be sure and select a boxwood cultivar with a high level of resistance which will not require a fungicide treatment.
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Round nodules on willow tree branches
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Date Posted: Fri, Aug 06 - 8:51 pm
- My neighbor's willow oak dropped some branches in a recent storm and we noticed many small round nodules clusters on the branches. I have pictures and can up load if required. Neither of us have ever seen anything like this before. The tree is probably over 100 years old and is in the Museum District. Is this a disease or a parasite?
- Without actually seeing a picture of the infected branch, I believe the most likely issue is related to scale insects on the tree. They will form these nodules and feed on the nutrients in the tree branch tissues. If this is the case, the owner should determine how widespread the issue is throughout the tree. If infection is only in a few areas, or on lower branches, I would recommend cutting out those branch sections, bagging the infected material, and discard. If the infection is visibly more widespread, a safe, organic insecticidal solution spray would be recommended. Good luck, and feel free to reach out with any further questions.