The fall is a great time to improve our lawns. We have now passed the correct timing for overseeding lawns, but there are other improvements we can still make. Controlling perennial broadleaf weeds and winter annual weeds can be done in October and fertilizers may be applied if necessary.
Perennial broadleaf weeds including dandelions, creeping Charlie or ground ivy, and clover are best controlled in the fall once the weeds have begun their preparations for winter. In the fall, these perennial weeds will move sugars that they use for energy from the above ground portions of the plant down into the roots to store them for next spring. If they are sprayed during this phase of their lifecycle, they are more likely to take that herbicide down into the roots to be more effective than if done in the spring. Spray these weeds with a 2,4-D product 2 or 3 times from late September through the end of October. Wait to spray after temperatures consistently drop to below 80 degrees so the herbicide doesn’t volatilize in hot, humid weather.
The fall is not the time to worry about or treat for summer annual weeds such as crabgrass. Those plants that are still alive will die with the first frost and the seed will not germinate until next spring when the weather warms back up again. However, you can treat now for winter annual weeds such as henbit and speedwell. Once they have germinated this fall you can use a 2,4-D product, which can be applied as a late October application both for the winter annual weeds and for perennial broadleaf weeds.
Using pesticides correctly
Remember, when using pesticides always be careful and apply pesticides according to the label. Any material used to maintain a landscape, including fertilizer, sand, or pesticides, can end up in the storm sewer and lead to pollution of lakes, rivers, and streams. In the same manner, even our grass clippings and leaves can pollute our water supply. There are ways to manage our landscapes while reducing water pollution.
The following will help when managing our lawns this fall:
Any fertilizers, pesticides, and grass clippings should be swept back onto the landscape. Using a leaf blower will work as well. The idea is to keep these items on plant material rather than on the hardscape that leads easily to the storm sewer.
Raking up leaves in the fall will also help reduce the amount of leaf debris that ends up in water.
Check your sprayers before using to ensure they are properly calibrated and the nozzles are not clogged.
Thatch layers in the lawn can become a natural barrier to prevent infiltration. Aerate the lawn to reduce the thatch layer to allow lawn products to infiltrate their intended areas.
As for fertilizer applications, the fall fertilization is the most important fertilizer application for a lawn. However, fall fertilization recommendations have changed over the past couple of years. For a lawn, a Labor Day to mid-September application of slow release fertilizer is still recommended. Apply a granule with 50% slow release nitrogen or less. If additional nitrogen fertilizer is required later in the fall, use a product with a quick release nitrogen in mid-October. We used to recommend Halloween or later for the second fertilizer application and we thought two applications were necessary. New research is showing us that a second application of nitrogen fertilizer may not even be necessary, but if it is, we should move the timing up to more like Columbus Day rather than the typical Halloween time frame. This information is from Bill Kreuser, Assistant Professor and Turfgrass Extension Specialist from the University of Nebraska-Lincoln.
This is the Q&A for the Yard and Garden show for April 13, 2018. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through August 3, 2018. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.
Guest Host: Kyle Broderick, Coordinator of the Plant & Pest Diagnostic Clinic at UNL
1.The first caller of the show wants to know when is the time to trim roses?
A. Anytime now would be good. When the show aired, snow was predicted for over the weekend, so it is advised to wait until the snow has melted before pruning the roses to avoid damage from cold weather.
This caller also has moles, how do they get rid of them in the yard?
A. Harpoon traps work best for moles. To help the trap work better, stomp down a run 2-3 times before placing the trap in the run. This shows that it is an active run and it will lead the mole to continue to pop the soil back up after you knock it down. For more information, visit the UNL Wildlife site and choose the NebGuide on Moles
2. How do you kill grass growing in peony plants
A. Fluazifop is the active ingredient found in Grass-B-Gon products. This will kill grasses and not harm ornamental plants. It can be sprayed right over peonies and iris’ and other ornamental plants. Be sure to not spray your turf or ornamental grasses with this product as it will kill any grass it contacts.
3. A woman has a substance on her artificial turf. Is it mold or moss?
A. It would be moss if it has a green color, but if it is more of a black color, it would be mold. Dry out the area to reduce the problem. You can also clean the artificial turf with a vinegar solution.
4. A caller has an apricot tree with blossoms that are starting to show color. Is there anything that can be applied to protect it from the frost, snow, and cold temperatures in the forecast for the weekend?
A. There are no sprays to protect the fruit tree from cold damage. Watering the tree prior to the cold weather can help protect it because trees use moisture to protect itself in cold weather. This is the reason that peaches and apricots have years of low production, they tend to bloom earlier than the frost free date which will cause cold temperatures to damage the developing flower buds.
This caller also wants to know if they should spray their trees for pests now or if they should apply preen in their gardens?
A. No on both of these questions. There is snow and rain in the forecast which will wash the pesticides off the trees. It is too early to use preen because it stops the germination of annual plants. Winter annual plants emerged last fall and summer annual plants won’t germinate until the soil temperatures have warmed up more. Applying preen too early in the season will cause it to break down sooner in the summer allowing later germinating summer annual plants to emerge once the preen is gone for the year. It is best to wait until soil temperatures have warmed up closer to when the seeds will germinate.
5. This walk-in listener has mounds that developed in their pasture area after they burned it this spring. What are the mounds from?
A. These mounds developed from ants. Upon closer inspection, Jim Kalisch from the UNL Entomology department, has determined the ants are Larger Yellow Ants. The mounds will persist as long as the land is not tilled. The ants favor building their nests in clumps of bunchgrass, as it provides stability and protection, and the ants tend root aphids on the bunchgrass roots underground. If the mounds are not desired, tilling the ground will reduce the mounds.
6. Can preen be used on asparagus before it emerges?
A. Yes, preen only stops the germination of annual seeds. Asparagus is a perennial plant coming back from the roots, so it will not be inhibited from growth if the preen is applied before it comes up. Make sure you are using the preen that is labeled for use in asparagus, not the general preen that is used in ornamental plantings.
7. A caller has grubs in his vegetable garden space. What should be done about that?
A. A few grubs in the garden won’t be problematic. Mostly, grubs are only damaging to potatoes and not our other vegetable plants. If the population is high enough and damage is occurring, the vegetable garden would need to be moved for a year to treat with chemicals that are not labeled for use in a vegetable garden. There are no products available to treat grubs that are labeled for use in vegetable gardens safely.
8. This caller is taking care of a planting of hostas for the first time. What does he need to do to clean up the space?
A. Hostas die back to the ground every year, so once the weather is a little warmer more regularly, these plants can be cut off at the ground level to remove all of the dead leaves and plant material from last year. Make sure to refresh the mulch to 2-3 inches deep with new organic mulch. If the plants are too big, they can be divided and replanted in other locations. Depending on the size of the plant it can be divided into 2, 3, or 4 parts to replant in other locations or to share with friends. To divide the plants, dig them up and use a spade to cut it into pieces that are then replanted.
9. A caller has white pine trees that were transplanted last year that are now turning brown on the ends of the branches. What is causing this?
A. This could be due to a combination of transplant shock and winter injury. Fall watering will help protect newly planted trees from winter injury. Water these trees well throughout the season and they should improve over time.
10. This caller has an angel wing begonia that is overwintered indoors each year. Can it be placed outside during the summer months?
A. Tropical-type plants, such as this begonia, will not take temperatures below 50 degrees F, but they can live through our summer months. Once the temperatures are consistently in the 50’s and warmer, the potted plant can be placed outside. To prevent breakage of the branches, it would be best to place the planter in a location that is protected from high winds. Next fall, before the temperatures move too cold at night, move the plant back indoors to keep it alive through the winter. Spray the plant with an insecticide before bringing indoors to keep insect pests outside instead of bringing them indoors with the plant.
11. A caller has scrub elm trees that have started growing up in the asparagus patch. What can be done to kill the elm trees?
A. Right after cutting the elm off, paint the stump with a straight 2,4-D product. Don’t use tordon or triclopyr products as these can get into the roots of the asparagus, killing it. Treat the stumps early in the season before temperatures reach 80 degrees F to avoid volatization of the product and causing possible harm to the asparagus.
12. This caller has gnats from houseplants in the office. How can they control them?
A. These are likely fungus gnats from the houseplants. If you know when the gnats first appeared and you can link that to the appearance of a new houseplant, remove that houseplant to remove the majority of the gnats. Houseplant insecticide sprays can also be used. Repotting the plants, removing the majority of the soil from the roots will also help.
13. The last caller of the day wants to know how to control grass in a well-established asparagus patch?
A. You can spray the bed with glyphosate (Roundup) before the asparagus has emerged and no green from asparagus is present, but the grass is green. It would also be best to apply mulch around the plants to reduce new weeds from emerging.
This is the Q&A for the Yard and Garden show for July 7, 2017. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through July 28, 2017. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.
Guest Host: Bob Henrickson, Assistant Director of the Nebraska Statewide Arboretum
If you enjoy reading my Q&A from the show each week, take my quick survey at: http://go.unl.edu/44qr and be entered to win a free plant book or some free UNL gifts.
1.The first caller of the day has 10 lilacs growing in a lawn which are now getting a gray film on the leaves. What is causing this problem?
A. This is due to powdery mildew. This is a common problem on lilacs. Lilacs often get this disease if they are planted too closely together reducing air flow or if they are planted in heavy shade. If these plants are not growing in either of these environments, it is likely due to the wet spring we saw this year. Fortunately, this disease is not very damaging to the plants and there is no need to treat for it.
2. A caller has many American elm trees growing in his pasture that seem to suddenly be dying this year after the leaves turn brown and curl up on the branches.
A. Unfortunately, this is likely due to Dutch Elm Disease, which is still present and active in Nebraska. Many of our trees can grow for a few years and then the trees get large enough and conditions become conducive, that it shows up and kills the trees fairly quickly. The only management strategy is to remove and destroy the infected trees to reduce the spread to other trees.
3. What are the blue flowers blooming along the roadside now and can the seed be purchased somewhere?
A. That is chicory, a non-native plant often used in roadside mixes. The seed can be found in some roadside mixes or at local seed sources.
4. A caller has a sunset maple with leaves that are curling and falling off the tree. What could be wrong with the tree?
A. This could be due to herbicide drift. Trees stressed by herbicide drift will often lose their leaves and push new growth. As long as they are producing new leaves that are not curled, the tree will likely be fine. However, many years of damage from herbicide drift can cause more stress and even possibly death.
5. This caller has voles in their yard. How can these be controlled?
A. Snap mouse traps can be placed in the runs perpendicular to the runs. These traps will catch and kill the mice. Here is a guide on vole control
6. A caller has a copper-colored beetle in her elm trees that are causing holes in the leaves. What would this be and how can they be controlled?
A. This could be a Japanese Beetle, an invasive insect from Japan. It is a green beetle with copper-colored wings. These beetles need to be controlled as they can do a lot of damage quickly. They chew on the leaves causing a skeletonization of the leaves as they leave behind the leaf veins. They can be treated with a insecticide containing imidacloprid.
7. A caller has a grass that grows in her lawn. The grass grows in a large circle about the size of a dinner plate and tends to turn brown in any kind of drought when the rest of the lawn does fine, but thrives in higher moisture content. What would this be and how can she make her lawn look more uniform?
A. This could be a cool season weedy grass species. They are often found in our lawns growing in a large circle. I would recommend spot spraying the areas of this different type of grass and then reseeding. This would be best done this fall. Be sure to spray the spot while it is still green and actively growing and use a product such as glyphosate. Overseed the areas in September.
8. This caller has hollyhocks with brown spots on the leaves. What could this be from?
A. This is likely due to hollyhock rust, a common fungus of hollyhocks. Remove the leaves as they develop the disease and destroy the leaves and plant parts removed in the fall cleanup. Fungicides can be used if necessary, such as a liquid copper fungicide.
9. A caller has peach trees that have developed some insects in the peaches making them unedible. What can be done about that?
A. There are a lot of different insects that feed on the fruits of peaches. The oriental fruit moth is one. For any fruit tree, either deal with some insect and disease damages throughout the years or keep your trees on a spray program. Spray every 10-14 days throughout the growing season with an Orchard fruit tree spray that contains two insecticides and a fungicide. Avoid spraying during full bloom. For more information, visit food.unl.edu/local-food-production
10. This caller has a sycamore that has shed some leaves and is now shedding bark. What is wrong with the tree?
A. The shedding bark could be normal. Sycamore trees have an exfoliating bark that is normal to give it the camouflage bark appearance. It may have been hit earlier this spring with anthracnose causing the leaves to drop. Anthracnose is a minor, but common, disease of sycamore trees. It is more prevalent in wet weather, such as this spring. There is no control for it, but the tree should be fine.
11. A caller has been trying to seed grass where a septic tank was and can’t get it to grow. What is wrong?
A. At this point in the year, it would be best to wait until fall to plant grass seed due to the heat, humidity, and lack of rain. However, if you have been trying in the spring and fall and can’t get it to grow, I would recommend getting a soil test done of the soil where this problem is occurring. This will help tell if the soil has other problems because of the septic tank or what was put back into the hole. It was also determined that this is an area around a large tree with a great deal of shade, if the area is too shady for grass, try a groundcover or a carex species that will grow better in more shade.
12. When is the best time to spray for bagworms?
A. Now would be a good time since the bags have emerged. Make sure you spray before the bags are 1 inch in length for best control. You can use any general insecticide for controlling bagworms such as sevin, eight, bifenthrin, tempo, or Bt can be used for a safer control method. Bt will not harm bees and other beneficial insects.
13. A caller has a Norway Spruce that is 8 feet tall. It has been drying up since this spring and looks like it is dying. The tree has been planted here for 5-6 years and is watering slowly every 2 weeks since the trees were planted. What is causing it to die?
A. This could be due to overwatering. The roots of the trees need to breathe in between waterings. If the caller is filling a moat around the trees with water every 2 weeks for this many years, it would be excessive.
14. The final caller of the day wondered if the yard could be sprayed to help with chiggers? He also wondered when the time was to use sedgehammer on the lawn?
A. Nothing can be sprayed on the lawn to entirely help with chiggers. The best defense against chiggers would be to use insect repellent that contains DEET and to wear light colored clothing. Sedgehammer is best used before June 21st or the longest day of the year to help reduce the populations of nutsedge for next year. However, it can still be used this late in the year to kill what is in the lawn this year.