Master Gardener – Search
Searching: treatment
If you don't see the answer you're looking for, try submitting your question.
Mosquito Management
-
Date Posted: Thu, Sep 03 - 6:41 pm
- Mosquitos!!! The bane of our existence here in Midlothian VA where we have lived for the last 23 years. We love to garden and spend lots of time outside. We have tried mosquito shield spray services such as Orkin, Thermacell repellents and of course Off spray and wipes. Any hour of the day, mosquitos swarm to us. In less than 5 minutes they find us no matter what. We've also tried prevention, such as cleaning out gutters, eliminating standing water etc. Do you have reports of products or prevention that have been most effective for Richmonder's wanting to spend time outdoors in their gardens? Thanks so much!
- Thank you for reaching out! Unfortunately, mosquitoes can be especially challenging in our warm, humid Richmond-area summers, and it sounds like you have already tried many of the common recommendations. The most effective approach is generally to combine several mosquito-management strategies. You are already doing one of the most important things by eliminating standing water. We recommend continuing to check the property at least weekly, since mosquitoes can develop in surprisingly small amounts of water. In addition to gutters, look closely at flowerpot saucers, tarps, wheelbarrows, toys, buckets, birdbaths, corrugated drain extensions, trash/recycling containers, tree holes, and anywhere else rainwater may collect. Containers should be emptied and scrubbed, not just dumped, because mosquito eggs can remain attached to the sides. For water that cannot reasonably be emptied, such as rain barrels, some water features, or other areas of persistent standing water, consider using a mosquito larvicide containing Bti (Bacillus thuringiensis israelensis) according to the product label. These are commonly sold as mosquito dunks or bits and target mosquito larvae before they become biting adults. For personal protection while gardening, EPA-registered repellents remain one of the most reliable options. Active ingredients to look for include DEET, picaridin, IR3535, or oil of lemon eucalyptus/PMD. If you dislike the feel or smell of DEET products, you may find a picaridin-based repellent worth trying. You mentioned Thermacell products as well. These are a type of spatial repellent and can be helpful within a limited area, but their effectiveness can be affected by wind and the size of the area you are trying to protect. They may work better for sitting on a patio than for moving throughout a garden. One additional, simple option to try is air movement. Mosquitoes are relatively weak fliers, so placing a strong outdoor fan near a patio, gardening work area, or other place where you spend significant time can make that particular area much less hospitable to them. We would be cautious about relying heavily on routine whole-yard insecticide spraying, particularly in a garden with flowering plants. Products used to kill adult mosquitoes can also affect non-target insects. CDC guidance specifically recommends avoiding applications to plants in bloom or plants being visited by bees and butterflies. If you do choose professional mosquito treatment, we would suggest asking the company exactly what product they use, where they apply it, and what steps they take to minimize exposure to pollinators. Finally, if mosquito numbers are truly extreme despite diligent management on your property, the source may not be entirely within your yard. Nearby properties, drainage areas, neglected containers, or other standing water can continually produce mosquitoes that move into your garden. I hope this gives you a few additional strategies to try. Unfortunately, there isn't one product that will create a completely mosquito-free garden, but combining breeding-site reduction, larval control, personal repellents, and protection of the areas where you spend the most time can make a noticeable difference.
Question
Answer
Ground Bees
-
Date Posted: Tue, Aug 11 - 11:24 am
- Our lawn is infested with "ground bees." They emerge in the spring for about two weeks. They do not sting, but they are an annoyance. And they are destructive of our lawn. How can we get rid of them? Are there effective insecticides? Any help will be appreciated
- Thank you for reaching out with your question. Ground bees are solitary, ground-nesting native bees that are among the first pollinators to emerge in spring. Although they often nest in large groups, each female creates and provisions her own nest. They are generally non-aggressive and rarely sting as you mentioned, and their activity typically lasts only a few weeks before the adults disappear for the remainder of the year. During the rest of the year, the developing bees remain underground until the following spring. Because they are important pollinators, Virginia Cooperative Extension recommends leaving them undisturbed whenever possible. Ground bees prefer dry, well-drained soil. If they are nesting in an area where their presence is problematic, keeping the soil moist during their brief spring nesting period can discourage them from using that location in future years. Improving turf density through proper fertilization, overseeding, and irrigation can also make lawns less attractive for nesting by reducing areas of exposed soil. Virginia Cooperative Extension does not generally recommend insecticides for ground bees because of their beneficial role as pollinators and because their active period is so short. By the time treatment is considered, they are often nearly finished nesting for the season. If the bees are creating a safety concern in a high-traffic area, you may wish to consult a licensed pest management professional, but for most situations, tolerating them for the brief period they are active is the preferred management approach. Here are two online articles that discuss ground bees that you may find helpful: https://fairfaxgardening.org/ground-nesting-bees/ https://www.richmonder.org/ground-nesting-bees-are-a-spring-phenomenon-in-richmond/
Question
Answer
Plant identification and recommendations
-
Date Posted: Wed, May 01 - 12:03 am
- I have a lot of what I am told is moss in my yard. Have pictures to send. Can you identify it and provide any treatment options?
- Thank you for reaching out to the Richmond Master Gardeners. I will send you an e-mail to be able to get the pictures from you and we will try to give you some assistance.
Question
Answer
Crape Myrtle Bark Scale
-
Date Posted: Wed, Feb 28 - 12:46 am
- Other than digging up and destroying crape myrtles what is the next best solution for crape Myrtle scale?
- A systemic insecticide in the spring is the recommended treatment for Crape Myrtle Bark Scale (CMBS) . A soil drench of imidacloprid or dinotefuran is recommended when crape myrtles begin to leaf out in the spring, usually around April. Personally, I've had success with Bonide products and find them to be available at many local garden shops. Bonide has an annual tree and shrub product that has an active ingredient of imidacloprid. (Other insecticide recommendations from the extension office are available here: https://www.pubs.ext.vt.edu/456/456-017/456-017.html) If you decided to go with an insecticidal soap spray, just be sure to refrain from applying it when pollinators or other beneficial insects such as ladybird beetles are present on the trees. If you would really prefer to stay away from insecticides, another control option is to lightly scrub the main trunks of crape myrtles with soapy water made with mild dish detergent and a stiff-bristled brush to kill and remove CMBS. This also removes some of the sooty mold and the loose exfoliating bark that shelters CMBS, exposing the scales to any spray treatments that may be applied. And finally, its important to check and be sure your control methods are working. To assess if a control treatment was effective or not: check for live CMBS by running a fingernail over the scales and looking for a pinkish-red fluid. Dead scales will be dry, but their white bodies may persist on the trunk and branches of crape myrtle until they weather off. Good luck!!
Question
Answer
Crepe Myrtle Bark Scale
-
Date Posted: Thu, Feb 08 - 3:03 am
- Hello! Would you be able to recommend the best product for treating a severe case of Crepe Myrtle Bark Scale? The tree is about 5 years old and has been very healthy until last year when it got the scale. I have heard that it is best to treat with a systemic insecticide in the spring but there are a lot of products out there and the prices very quite a bit. Also if there is a better way to treat than an insecticide please let me know! Also a lot of the products recommend a treatment based on the trunk size if the crepe myrtle has multiple trunks do I add all the trunks up or should I treat based on a single trunk size? Thank you so much !
- These are great questions about Crepe Myrtle Bark Scale CMBS). I had to do a little bit of research myself to figure out how to best give you some guidance. A systemic insecticide in the spring does seem to be the recommended treatment. A soil drench of imidacloprid or dinotefuran is recommended when crape myrtles begin to leaf out in the spring, usually around April. Personally, I've had success with Bonide products and find them to be available at many local garden shops. Bonide has an annual tree and shrub product that has an active ingredient of imidacloprid. (Other insecticide recommendations from the extension office are available here: https://www.pubs.ext.vt.edu/456/456-017/456-017.html) If you decided to go with an insecticidal soap spray, just be sure to refrain from applying it when pollinators or other beneficial insects such as ladybird beetles are present on the trees. Here are some guidelines for measuring the circumference of the tree trunk: 1. If it appears that a tree actually represents two or more trees that have their trunks pressing together, we measure the largest trunk. 2. If it appears that the tree tree is a single tree that splits below 4.5 feet, we measure at the narrowest point between the split and the ground. 3. If it appears that the tree tree is a single tree that splits above 4.5 feet, we measure the trunk at 4.5 feet. If you would really prefer to stay away from insecticides, another control option is to lightly scrub the main trunks of crape myrtles with soapy water made with mild dish detergent and a stiff-bristled brush to kill and remove CMBS. This also removes some of the sooty mold and the loose exfoliating bark that shelters CMBS, exposing the scales to any spray treatments that may be applied. And finally, its important to check and be sure your control methods are working. To asses if a control treatment was effective or not: check for live CMBS by running a fingernail over the scales and looking for a pinkish-red fluid. Dead scales will be dry, but their white bodies may persist on the trunk and branches of crape myrtle until they weather off.
Question
Answer
Browning Dwarf Arborvitae
-
Date Posted: Wed, Oct 11 - 12:47 am
- Dwarf Arborvitae has brown sections, on am effort to cut them out, it appears black underneath. What is happening? Thank you.
- I'm sorry you are having these concerns with your Dwarf Arborvitae. The first thing that comes to my mind is canker. Canker is infected wounds in the branches caused by fungi. Wounds can be caused by pruning, storm damage, cold damage, or excessive wetness. In plants with canker, you will observe yellow to reddish-brown branches in the middle of healthy green branches. Closer to base of the branch you may see slightly sunken, reddish cankers with profusely exuding resin. Black pustule-like fruiting bodies known as pycnidia may be seen breaking through the bark. There is no real treatment for canker stem diseases. The fungus survives in infected bark tissues, so it is best to prune all infected branches about 3-4 inches below the canker area. Spread of the fungus can be minimized by sterilizing any blades used between all cuts with a 10 percent bleach or 70 percent alcohol solution. Try to prevent damage to trees. Stressed and wounded plants are more likely to be infested. It is best to keep dwarf trees as open as possible so that they will dry out after rain. Prune to allow air flow in plants. Clean out leaves from the insides of shrubs. Do not bury plants too deep in mulch. Prune out infected branches and fertilize affected trees if needed. Good luck!!
Question
Answer
Eradicating Giant Taro
-
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!
Question
Answer
Shasta Daisy-browning, die back
-
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! "
Question
Answer
Rudbeckia-leaves blackened
-
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!
Question
Answer
Controlling Japanese Beetles
-
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!