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Eradicating Giant Taro
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Date Posted: Wed, Aug 18 - 1:43 pm
- Continuing along the theme of invasive species, we have several clumps of elephant ears (giant taro) in our yard that we are trying to eradicate. We have dug them up twice already and they keep coming back. Any tips or solutions that can rid of us of this invasive plant? Thank you very much.
- Good morning, and thank you for your question! Giant Taro (elephant ear) are dramatic and beautiful to admire, but we know they can be problematic spreaders. This invasive plant is typically hardy only in zones 8-11, but with our recent mild winters here in zone 7, they easily thrive. They are best planted in very large pots in the garden or on the patio, where they can be contained and enjoyed without the spread. The best organic approach for removal and eradication of elephant ear in the garden is to simply dig them up (and likely repeatedly), until they are all gone. It sounds like you’ve taken this approach twice and they’ve come back. Be sure and dig wide and deep enough to remove all small pieces of the corms (tubers), and dispose of them in a plastic garbage bag. These small pieces can colonize and form new plants if left in the ground. Remove the soil in the area and replace it as well. As you’ve learned, this often requires repetition until they are all gone. If any new growth emerges during the fall, repeat the process, cutting down all growth to 1” above the ground and dig up the tubers and all small corm pieces in the ground before winter. I wish I had more magic tricks for you to try to solve this. Perhaps we’ll have a colder winter this year (more in line with our climate zone) which will help as well. Good luck!
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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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Rudbeckia-leaves blackened
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Date Posted: Tue, Aug 17 - 8:51 pm
- I’m having a problem with my Rudbeckia Goldstrum. The leaves are blackening and the plants dry out and die. I took pictures but can’t figure out how to attach them to this message. So far the problem is only with the Rudbeckia.
- Hello there, 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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Controlling Japanese Beetles
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Date Posted: Tue, Aug 17 - 8:50 pm
- How can I safely control Japanese beetles? They're devouring my roses. I don't want to use anything that would hurt bees or hummingbirds.
- Thank you for your question. I certainly understand the extent of damage Japanese beetles can cause to all parts of the Rose bush - buds, leaves, and flowers! A very safe, organic, and effective means to control Japanese beetles is a routine spray of a Neem oil solution. A Neem oil solution both kills and repels the beetles when applied every 7-10 days. This solution is totally organic and non-toxic to bees or birds. Simply mix 2 tablespoons of Neem oil per gallon of water, and spray all parts of the rose plant. A side benefit is that this Neem oil solution also controls aphids, lace bugs, mealybugs, and spider mites. Another solution is a simple soap and water solution (although not quite as effective at repelling the beetles as the Neem oil solution). Mix 4 tablespoons of dish soap with water in a spray bottle and spray all parts of the plant. Best of luck! Let us know if you have other questions!
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Mint-powdery mildew
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Date Posted: Tue, Aug 17 - 8:48 pm
- I am growing organic mint in a pot. Noticed that there is powdery white stuff on the leaves. What is that and how can I treat it naturally? Is it safe to eat / use the mint leaves if it has this white powdery stuff on it? Thanks Vilma
- The powdery white stuff you see sounds like the fungus powdery mildew. This is a very common problem with many plants but it is not difficult to correct in this type of situation. If you can, first, isolate the plant and remove affected leaves. There are many solutions. I'll list 3 here and you can see which one suits you and try another if the first choice doesn't do the trick. 1.Try using this combination-1 gallon water, 1/2 teaspoon non-detergent soap, 1 tablespoon baking soda. Pour this solution into a clean spray bottle and liberally apply this to the plant. The soap will help the diluted baking soap stick to the mint leaves and stems. It's best to water the plant well before using the solution and don't apply while the plant is in hot sun, early morning is best. You can repeat this every 7 days and after a rain. Some people feel this works best as a preventative rather than a control. So if you find that you're having the same issue with powdery mildew year after year, apply this solution at the beginning of the season. 2. Another solution is a mixture of 3 tbsp. of neem oil to one gallon of water, sprayed onto affected plants every 7-14 days. Again, don't spray while the plant is in hot sun to avoid burning. 3. And yet another possibility is using milk. I have never tried this but I understand you can get some good results. Try a mixture of 4 parts milk to six parts water and spray bi-weekly. Apply in early morning. In all cases, try any solution on a test leaf first to see how the plant responds. And no, I wouldn't eat the leaves that are covered in powdery mildew but once the plant shows no signs of the fungus, feel free to use the plant in whatever dish you like. Good luck and let us know which solution was successful for you.
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Raised beds - yellowing leaves
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Date Posted: Tue, Aug 17 - 8:41 pm
- I created new raised beds and filled them with Miracle Grow Raised Bed soil combined with mushroom compost. All of my plants have yellow leaves. The soil should be provided the necessary nutrients, and I was wondering if the weather might be part of it? Can you give me an idea of what I should do? Thank you
- Hello - interesting question. The first thing that comes to mind is your soil. It sounds like you have created a very rich soil for your new plants. Typically, yellowing leaves can indicate a nutrient deficiency, and/or the soil is too wet. As you know, mushroom compost does a good job of soaking up a lot of water and helps keep soil moist. It is also nutrient-rich, and contains a high degree of soluble salts. I’m wondering if your ratio of mushroom compost to soil is too high. The mushroom compost should make up about 1/4 of the total volume of the soil. If your soil is too concentrated and the plants are seedlings or are very young, this may result in your plants dying. The soil may actually be too rich for them. Also make sure your soil is not staying too wet. It should be allowed to dry before adding water. Good luck, and let us know if we can help further!
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Tomato-Blossom End Rot
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Date Posted: Tue, Aug 17 - 8:37 pm
- I'm just starting to see fruit on my tomato vines, but unfortunately they look to already be developing blossom end rot. I'm using a mixture of organic soil with fertilizer and perlite, and I'm not sure if the plant is salvageable. What can I do to help this plant? And what advice can you give for other tomato plants to prevent this blossom end rot? Is there something I can apply early on to prevent this? Thanks!
- Hello there, This is a pretty standard issue with tomatoes. Generally, the cause is inconsistent watering and/or a calcium deficiency. So the first step would be to establish a consistent level of watering for your plants. Of course, Mother Nature plays a role here as well, you can't control that. If you're sure that watering is not the problem, then you need to think about calcium. Without testing the soil you won't know the level of deficiency. But if you want to proceed, there is a short-term fix. I haven't tried this myself because the cause for me was generally a watering issue, but you can spray the plant with a calcium solution. That will buy you some time to increase the calcium content in your soil. There may be enough calcium in the soil but the ph of the soil may be preventing the plant from absorbing it. I don't understand all the chemistry of this but soil ph is the root of plant happiness. A ph of around 6.5 will do. Try adding some fast-acting lime (don't use dolomitic lime) and working that into the soil about 12 inches deep.The lime frees up the calcium from the soil. As I said previously about chemistry....This is a time-honored practice so it should work for you if, in fact, you find that watering is not the problem. If you would like to have a soil profile done, please let us know and we can send you a soil test request kit. Good luck with the tomato harvest!
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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.