This time of the year is always full of activities to do outside. It is a great time to get outside in the comfortable weather. Lawncare is always at the top of our spring outdoor ‘to do’ list, and crabgrass is number one on the concerns.
Crabgrass is a summer annual grassy weed that takes advantage of thin areas in our lawns to become established. As a summer annual weed, crabgrass germinates in the spring and, if not controlled, new plants continue to germinate throughout the summer. Each plant grows for one summer, then dies with the first hard frost in the fall. New crabgrass that you see in your lawn each year is from seed that was set the previous year by the crabgrass growing before.
Crabgrass is a problem in our lawns. Each plant will compete with our desirable grass species. Once crabgrass gets into a lawn, it will compete with our grass for water, sunlight and growing space. Plants produce a large amount of seed that will germinate the following year, creating an ongoing problem on your lawn.
Crabgrass is difficult to eradicate once it becomes established, so it is better to prevent this weed from becoming established in the first place. Crabgrass preemergent herbicides are used to inhibit the growth of young seedlings, destroying them before they can emerge from the soil. Which is why many people prefer to use a preemergent herbicide to control the crabgrass in their lawn.
Preemergent herbicides should be applied before crabgrass has started to germinate, which happens when soil temperature has reached 55-60 degrees F, measured at 4-inch soil depth, for at least four days. This is not based on a date range, because soil temperatures differ from year to year. It is based on the weather conditions for that year. We have reached that point now this year.
It is not beneficial to apply the preemergent too early in the year. Once applied products begin to degrade and breakdown. If your application is made too early, before crabgrass germination has started, you are wasting your product and monty because you will have a shortened period of control once crabgrass does start germination.
Plan on making two applications of preemergent to give season-long crabgrass control. Purchase enough product in spring for two applications; garden centers often run out of preemergent products by the end of spring so it could be hard to find later in summer. Each product has a slightly different length of residual action, so follow the product’s label directions on when the second application should be made.
Controlling Existing Plants
Post-emergent herbicides can be used to control crabgrass that has emerged in your lawn. Products containing Mesotrione, commonly found in the product called Tenacity, works as both a pre- and post- emergent herbicide on grasses and broadleaf weeds. It can also be used at seeding if you have a history of crabgrass problems and need to overseed.
The other commonly used post-emergent herbicide for controlling crabgrass would be products that contain Quinclorac, commonly found in the product called Drive.
If crabgrass does appear in your lawn, you can reduce future problems by keeping plants mowed short enough that they don’t produce seedheads. Then at least there won’t be additional seed in the soil to increase your problem next year.
This is the Q&A for the Yard and Garden show for April 14, 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: George Pinkerton, Director of Landscape Maintenance at Downtown Lincoln
1. The first question came from a caller wondering what the timing is for crabgrass preventer?
A: Typically we go with mid-to late April for application of crabgrass preventer. Crabgrass germinates when soil temperatures reach 55-60 degrees Fahrenheit. In most of the Southeast Nebraska area, we have just recently hit that. Anytime in the next couple of weeks would be fine to apply your crabgrass preventer. It might be best for control to apply a split application this year. For a split application, apply half of the recommended rate now and the other half of the recommended rate 8-10 weeks later. The split application will give you a longer season of control for crabgrass and other annual grassy weeds.
2. A caller was wondering about their gladiolus bulbs. They have had problems with thrips insects in the past and they had heard they should soak their bulbs in lysol to control them. Is this a good method of control or is there something better?
A: As it turns out, you can soak the corms in a solution of lysol water prior to storage of the corms over the winter months, according to the University of Minnesota Extension. You can also dust the corms with a sevin dust prior to storage in the late fall, store them with mothballs, or store them at colder temperatures such as 35-40 degrees F as well. If you are looking for control at this time, it would be best to spray the plants as you see the streaking damage beginning from the thrips feeding in the spring and summer months. You can use any general insecticide for this.
3. This caller has a sugar maple that was hit with hail 5 years ago and now has a great deal of damage to the trunk of the tree. They have sprayed the trunk with a sealant and used a wrap. Will the tree survive or should it be removed now?
A: At this point, I would observe the tree to watch for signs of death occurring through the tree. The damage that is there cannot be fixed now that it has occurred. If you don’t like the look of the damage you can remove and replace the tree or you can wait until it starts to dieback. It is hard to say how long the tree will live now that the damage has occurred.
4. A caller wants to reseed. What seed should he use?
A: For a new seeding, use a turf-type tall fescue or a Kentucky bluegrass. Use either 100% of either of these types or use a 50% mix of the two. For more information, see this article from the UNL Turfgrass Department on Choosing Grass Seed.
5. A caller has a section in fairly high shade that died out last year. Why and can it be reseeded?
A: In locations of very high shade turf doesn’t always do well. The caller said this had been growing there for 25 years so it could have been a fluke that the lawn died out last year. You can reseed now with regular turf or you can use a shady groundcover such as a carex species.
6. When is the time to transplant coreopsis to a location with more sun?
A: Now would be a great time. Mid April through mid-late May is a great time to transplant perennials.
7. This caller has some large pin oaks that need to be pruned to make it easier to mow underneath the tree. Is it too late now to do that?
A: Yes, it would be better to wait until late fall to prune the oaks now. Oak trees are susceptible to oak wilt which is spread by a beetle in the summer months. It is best to avoid pruning them at this time of the year to reduce the incidence of disease.
8. What kind of tree would be a good choice for shade production in a backyard?
A: Any of the oak species, shagbark hickory, sycamore, Linden, Kentucky coffeetree, Black locust, thornless honeylocust, hackberry, and many others.
9. A caller wants to know what to do for management of curly dock?
A: 2,4-D or Trimec can be used this time of year or use a mixture of 2,4-D and Roundup.
10. What do you do for thistles growing throughout a yard?
A: 2,4-D or Trimec, but these products are best used in the late fall or before flowering. Thistles are a biennial so if you can dig up the plants as a rosette in the first year of growth they will die.
11. This caller has cherry trees that are suckering. Can one of the suckers be dug up now to start another plant?
A: Yes, it can be done now, but fall would be a better time of the year for this. If it needs to be done, it can be done now. However, depending on the type of sucker growth, the new plants may not be the same as the original plant or they may have weak growth.
12. An email from a listener asked what is wrong with his pin oak that has leaves that are curled up like they were hit with a spray? He wondered if they were too close to the windbreak that is 20 feet away? Is there a certain distance you want to stay away from your windbreak when planting other trees?
A: You do need to give your trees space to grow, but pin oaks are often planted as a third, interior row to a windbreak. The spacing between rows would be 15-20 feet, so the proximity to the windbreak would not be a problem in this instance. Most of the time if a tree is lightly hit with spray drift from a pesticide, it will not show in the tree every year unless it is hit every year. In this case, I would ask for a picture or sample to help with further diagnosis.
13. When is the best time to transplant peonies? Why isn’t the rhubarb up yet?
A: Fall is the best time to transplant peonies. If necessary for construction or moving purposes, it can be done yet this spring. Plant them at the same depth at their new location. As for the rhubarb, give it a few more weeks to see if it comes up before giving up on it. If it is in a location that is more exposed to cold winds the soil may have not warmed up enough yet this spring.
14. This caller wants to know what type of fertilizer to use in a garden?
A: A low grade, balanced fertilizer is best for a garden, like a 10-10-10 or 12-12-12 with slow release fertilizer is best.
15. The final caller of the day wanted to know if now was the time to fertilize pecans?
A: Many of the trees in our environment have sufficient nutrients for growth and so fertilization on these pecan trees may not be necessary. If you are concerned with the growth of the tree, take a soil test to see where the fertility levels are. If it is growing fine, don’t fertilize it because our trees and other plants can be over-fertilized which can cause injury or even death.
Spring will be here before we know it. With all the warm weather lately, it is hard to remember that spring has not already sprung in Southeast Nebraska. But, with the warmer weather, there are a few things we can do in our landscapes and a few things we should avoid.
Don’t prune spring blooming shrubs this time of the year. Plants such as lilac, forsythia, spring blooming spirea, and some hydrangeas produce flowers in the fall of the previous year to bloom early in the spring. If you prune these plants now, you will cut of the flower buds and not have those flowers to enjoy this spring. So avoid pruning those shrubs in the spring. Spring blooming shrubs should be pruned immediately after they finish blooming in the spring. This will allow for the best growth of the plant and for best flowering each year.
Prune trees this time of the year. February and March are the best months of the year to prune deciduous and fruit trees. It is best to prune these trees during the winter months because it doesn’t affect fruiting that occurs in the spring and it allows the tree to seal up the wound quickly in the spring when growth resumes. It is also easier to see areas that need to be pruned in the winter months. You can see where branches are crossing or rubbing and where the branches are too dense. In addition, pruning in the late winter helps reduce the transmission of different diseases that aren’t active. However, it is best to avoid pruning maple, willow, poplar, birch, hackberry, Kentucky coffeetree, black walnut, honeylocust, and elm due to the high sap flow they have in the spring. Freshly cut wounds this time of year will cause the tree to “bleed” or have excessive sap flow out of the wounds. They are best pruned in the late summer to early fall to avoid sap flow.
Don’t uncover perennials yet. It is still winter, for a few more weeks. Many of our perennials are getting confused with the weather lately and some are starting to green up already. Tulips, Iris, and peonies are starting to emerge and crocus are blooming already. However, if you pull the winter mulch back from these plants or remove the plant material that was left on the plants through the winter, you will be exposing the plant to cold temperatures and removing its protection. The plant will have better survival and less winterkill if you leave them covered through the winter months.
Plan your gardens for the spring. Late winter is a great time to plan what you will plant in your vegetable gardens so you can format your plan to know what you have space for and to ensure that you move your crops around from year to year. This will also help you decide what seeds to start indoors. Mid-February through March is a good time to start the seeds of your chosen warm season crops indoors. Make sure that you have them in a warm location with 14-16 hours of light on them everyday.
Don’t use pre-emergent herbicides for crabgrass yet. The soil temperatures have been at an average of 40-45 degrees Fahrenheit over the past 7 days. Even as warm as it has been, crabgrass has not yet begun to germinate. If the temperatures continue at this pace, it will probably germinate early, but we still have a couple of weeks before we need to get the pre-emergent herbicides on. Remember, crabgrass germinates at 55-60 degree soil temperatures, so we still have a bit of warming up to do.
This is the Q&A for the Yard and Garden show for April 1, 2016. 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 5, 2016. 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 Hosts: Daryl Andersen and Kent Thompson from the Little Blue NRD
1. The first caller of the 2016 season has boxelder bugs in their home and need to know how to control them.
A. Boxelder bugs are not harmful to humans and will not populate within our homes. They enter in the fall and will emerge in the spring to leave our homes and go back outdoors. If found indoors, it is best to just vacuum them up or dispose of them in other manners. Barrier sprays around the home will not eliminate the problem, but they can reduce the numbers found in the home. Also, make sure that all cracks and crevices in your home are sealed up and that all screens on windows and doors don’t have any holes in them.
2. This caller has a very sandy lawn, what is the best turf for this area?
A. They may want to do a soil test to let them know for sure what they are dealing with. The best turfgrass selections for this area are Kentucky bluegrass and turf-type tall fescue. You can either select a mixture of these two turfgrasses or find 100 percent of either of them. These grasses perform the best in our environment. It might be a good idea to add organic matter to the lawn area to help improve the soil. Aerate the lawn first then apply a thin layer of compost and rake or lightly till that into the top layer, then overseed the lawn. Now is a great time to overseed, apply light, frequent watering to keep the seed moist while it is germinating.
3. This caller has an old windbreak. They are looking to replant parts of it with red cedars in a multi-row windbreak. How many trees would they need, what is the spacing for these trees? What kind of preparation should they do to the site prior to planting?
A. The NRCS has specifications on tree spacing based on the species. For eastern red cedar, they recommend 12-15 feet between each tree for spacing. Based on that and the space she has in her windbreak, she can figure out how many trees she should plan to order from the NRD. This fall would be a good time to till up the area to prepare it for the trees to be planted next spring. Kent Thompson suggests preparing the soil for tree planting like they would prepare the area for a garden.
4. This caller has ladybugs in their home and wants to know how to get rid of them and where they are coming from?
A. Ladybugs are a predatory insect, meaning that they feed on other insects, such as aphids. They can be found outdoors on many different plant species based on their food sources. Ladybugs are one of the insects that move indoors during the fall and then leave the house in the spring to go back outdoors, so we often see them in the home in both seasons. They are not harmful to us when they come indoors. If found indoors, it is best to just vacuum them up or dispose of them in other manners. Barrier sprays around the home will not eliminate the problem, but they can reduce the numbers found in the home. Also, make sure that all cracks and crevices in your home are sealed up and that all screens on windows and doors don’t have any holes in them.
5. Does wood mulch increase the likelihood of termites in our homes?
A. No, wood chip mulches are great to use for plant health. Termites will not survive in mulch if they are found in the trees being made into mulch due to the mulching process or because they dry out to quickly in mulches. However, it is best to not place mulch in locations where it is touching wood window frames or siding. According to Iowa State University, mulches increase the moisture in the soil which favors termite exploration, but any mulch will increase the moisture in the soil. So you can continue to use wood chip mulches because they are the best mulch for plants.
6. This caller wants to know if there are any regulations on rain barrels in the Fairbury area and if a rain barrel is a good option for watering?
A. There are currently no regulations against the use of a rain barrel in Nebraska. Rain barrels are a great option for watering, however it is recommended that this water not be used on vegetable gardens due to the contaminants in the water from the roof that may get into the plant parts we consume. It is a great way to save our fresh, clean water for other uses and to use rain water for watering the lawn, trees, shrubs, and flowers. Be sure to use the water in a timely fashion so that it doesn’t sit too long and attract mosquitoes, or use a screen over the entrance hole to keep insects out of the water.
7. A caller planted 3-4 feet tall blue spruces last year through the correctly recommended practices of planting a tree. He purchased the trees from a grower in Oregon. He watered as needed but avoided overwatering. The trees were checked for diseases with none found. What caused this death and how can he avoid it when he replants?
A. The sample of the trees showed that these trees suffered from environmental stress, which can be any number of problems. These trees are planted on a new site with no protection from wind and construction type of soil. The trees purchased for replanted should be purchased from a local source. A soil test could be done to see if there is any nutrients that should be added to the soil prior to planting for better health of the trees. Otherwise, this problem with environmental stress is common and hard to understand.
8. A caller has a sewer smell to his water, does he need new pipes?
A. Call the plumber or the city to have them look at it. It may be a situation where new pipes are needed, but we can’t tell for sure.
9. This caller has a problem with wild oats growing in their lawn, what can be done to eliminate this weed?
A. Glyphosate products, such as roundup, would be the only thing approved for use in the lawn. Then he will have to overseed. As long as the wild oats are up and growing now, he could go in and spray them and wait a week then overseed the area to bring grass back in and keep the wild oats out.
10. A person brought in a tree with odd, round structures on the branches. What are they and can they be controlled?
A. These are galls. Galls are produced by insects and are generally not harmful to trees. if they get high in populations, like they often do on bur oak trees, they can reduce the vigor and growth of the trees. It is very difficult to effectively treat them with insecticides. Cultural controls, such as cleaning up all debris and pruning out and destroying affected areas would be the best control.
11. This caller has fruit trees that are suckering or producing growth from the base of the trunk where it comes out of the ground. What can they do about these suckers?
A. Suckers can be removed from any tree any time throughout the growing season, and should be removed so they don’t get too large and take too much water and nutrients from the main plant. Don’t spray these or use any stump treatment on them after you cut them off or you can damage or even kill the main plant.
12. A caller has a red oak that is slower to leaf out but by May it is usually leafed out well with large, nicely colored leaves throughout the entire tree. Is this a concern that it is slow to leaf out?
A. If the tree does eventually come out and leaf with full-sized leaves throughout the entire canopy and the leaves have good color, it is not a concern. Some trees are just a little later to leaf out than others to avoid highs and lows of spring weather. As long as the tree does come out by summer with leaves the way they should grow and throughout the canopy, it is in good health.
13. This caller wanted to know when to fertilize with crabgrass control and when to overseed their lawn?
A. Crabgrass control and overseeding should not be applied at the same time as the crabgrass pre-emergence will also prevent the germination of our turfgrass seed. Overseeding can be done in the month of April, it is better to get it down from April 1-15 but can be done as late as the end of April. Once overseeding is completed, no chemicals should be applied until 3 mowings have been done on the new grass seed. Fertilization should be applied around Arbor Day. Crabgrass control needs to be applied when the soil temperatures have reached 55 degrees Fahrenheit because crabgrass germinates at 55-60 degrees Fahrenheit. As of April 1, Beatrice soil temperatures were at 47.6 degrees Fahrenheit, so we are still 1-2 weeks away from applying crabgrass control.
14. A caller has a soft water system that was installed and goes through the outside water faucet. Will this hurt plants that are watered by this softened water?
A. This water contains a higher level of sodium after it goes through the softener because the water softener exchanges calcium and magnesium for sodium. This sodium can replace potassium in plants and disrupt the functions in the plants, causing it to die, according to Illinois Extension. So, due to the high sodium content, softened water is not recommended to be used on household plants, lawns, or gardens. It might be a good idea for this caller to try out a rain barrel for watering their lawn and garden areas.
15. The final caller of the day has a pear tree that is 7-8 years old and has very low blooming. What is causing that?
A. Many pear trees need to be cross pollinated from a different species or variety of pear tree to produce fruit. It would be helpful to plant another type of pear tree in your landscape to help pollinate the tree. Also, remember to not spray chemicals on the tree while the tree is in bloom to avoid damaging any pollinator insects.
This is the Q&A for the Yard and Garden show for April 17, 2015. 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 31, 2015. 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: Dr. Paul Read, Professor of Horticulture, Viticulture Specialist
1. A Caller wanted to know if this was a good time to transplant rhubarb?
A: Now would be a fine time to transplant rhubarb. If you wanted to harvest from it yet this year, it would be best to wait until the fall to transplant it. Rhubarb should not be harvested from within the first 1-2 years after transplanting to allow the plant to build a good root system before harvesting begins. Make sure that rhubarb is planted in a well-drained location to avoid getting crown rot, a disease that will eventually kill the plant.
2. An email listener wanted identification and control strategies on her plant with purple flowers that is blooming now.
A: This is henbit, a winter annual that is flowering to complete its lifecycle. Because henbit is basically done growing for its lifecycle, it is best to leave it alone and let it die naturally in the next few weeks. The seeds are already in the soil for next year. Henbit is best controlled with a 2,4-D product in the fall. Mark the areas where henbit is found in your lawn this year and spray those areas in the fall. Management also can be achieved by overseeding turf into those areas where henbit is found or planting something else to compete with the henbit.
3. This caller wanted to know how to control clover
A: The best time to control clover would be in the fall with a couple of applications of a 2,4-D product. Applications of this product now can be useful, but will not eliminate the problem altogether. Be sure that when you apply 2,4-D to your landscape to not allow it to drift to any other broadleaf plant, including our trees, shrubs, and perennials. Also, only spray when the temperatures are below 80 degrees Fahrenheit.
4. A gentleman has a lawn that has been neglected for a while that he is struggling to keep turf alive in a full-shade location with poor soil. What can he do to get the turf to live there? Also, in another area of full sun, would dwarf fescue be a good turfgrass choice?
A: Because it is poor soil that had subsoil put on top of the existing soil, it would be best to aerate and add organic matter to try to improve the soil conditions. Full shade is difficult to grow turf in, so it would be best to choose a full shade perennial or groundcover or somehow prune the trees to improve the sunlight for the turf. Dwarf fescue is not a good choice because the root systems are not as deep as the turf-type tall fescues or Kentucky bluegrass.
5. What would be the fruit tree spray schedules for cherry and apple trees?
A: Orchard fruit tree sprays can be applied to both of these types of trees on a 10-14 day interval, while avoiding the blooming period to avoid damage to the pollinators. There are guides to spray schedules from many Universities including one for homeowners from Missouri Extension
6. A caller wanted to know what are some good varieties for pear trees in Nebraska? Does he need multiple species for pollination? How does he mulch these trees?
A: Pear trees are not self-pollinated so you will need to plant 2 different varieties to get fruit. Some good choices for Nebraska would include Luscious, Harrow Delight, Harvest Queen, and Seckel. A mulch ring is necessary to help the tree survive, it should be only 2-3 inches deep.
7. This caller used crabgrass preventer with fertilizer in it a couple of weeks ago and wants to know when he should use his weed and feed? Also, what type of care would he need for shrub roses he just planted this spring?
A: It would be best to just use a 2,4-D product anytime now and wait until the end of May to do another application of straight fertilizer to get through the summer, since he already applied fertilizer with his crabgrass control. The best thing for the roses would be to ensure that they are kept well-watered but not overwatered.
8. A gentleman has Philodendrons and Crotons as houseplants that he has moved outside for the summer. Now the leaves on the Philodendrons are curling up, why is that? Also, what kind of care should be given to the Croton, is misting a good practice for them?
A: These plants are tropical plants that we can grow indoors in our homes. The nights are still too cool for those, which is why the Philodendrons may be having leaf rolling issues. If the weather is predicted to get to the low 40’s to 30’s for the overnight hours, it would be best to bring these plants indoors. The Crotons should be watered properly from the base of the plant to ensure survival. Misting plants leaves the leaves wet which can lead to diseases.
9. What can be done to control ants found in the kitchen?
A: Terro ant baits work the best with the odorous house ant. Also, seal up all cracks and crevices in the foundation and around doors and windows. Clean up plant debris outside the home near where ants are found inside the home to reduce locations where ants may be hiding outdoors.
10. A lady has blackberries that are overgrown. How can she clean them up?
A: Cut out the old stems that are existing and continue to do this at the end of every growing season.
11. This caller has a 30 year-old pear tree that has never produced fruit. She has one pear in her landscape. Why would it not produce fruit?
A: Pears are not self-pollinated. Plant another variety and it should begin to produce fruit.
12. When is the best time to prune a snowball bush?
A: This is a spring blooming shrub, so it is best to prune it immediately after it has finished blooming for the year.
13. This caller wanted to know how to control Dandelions in her yard?
A: 2,4-D products can be used now but will have the best efficacy in the fall. If applied now, ensure that the wind is not blowing and the temperatures are at or below 80 degrees Fahrenheit for the day of application and the 2 days following.
14. This caller has started tomatoes and peppers from seed indoors and they are now becoming tall and spindly. What would cause that and when can they be placed outdoors?
A: They will need more light to avoid becoming tall and spindly. Also, be sure to buy clean and sterile soils for seedling production to avoid problems with Damping Off, a disease common to seedlings. Summer crops can be planted outdoors in the beginning of May, typically Mother’s Day is a good date to plant summer vegetable gardens.