Category Archives: Lawns
Perhaps it was the hard winter, but I’m finding the flowering trees to be exceptionally pretty this year! Corn and even some soybean went into the ground this past week too. In last week’s column I shared regarding planting considerations yet would still encourage growers to keep considering your local field conditions before planting. You’re hearing some of these same things from both Extension and Industry partners and we realize field situations differ. We keep repeating these things to provide reassurance when you’re questioning decisions. We’ve already seen problems with anhydrous application in too wet of conditions in some fields. We’ve already seen some situations that were too wet when corn was planted leading to problems with compaction, depth issues, and not closing seed vee’s. With the cold snap, it’s important to consider soil temperatures (preferably around 50F or warmer for next 48 hours), soil moisture conditions, air temperatures for the next 48 hours, potential for cold rain, and cold tolerance of seed. Soil temperatures are listed at http://go.unl.edu/soiltemp and I would also encourage you to check your own particular field conditions. Last week, I was finding soil temperatures in local field conditions to be cooler than what was being reported from high plains regional climate center. If you don’t have a soil temperature thermometer, you can do this with a meat thermometer (and just dedicate it for field use).
I can appreciate the added concern and stress with this week’s forecast. There’s several planting-related articles in this week’s CropWatch at http://cropwatch.unl.edu. Two really helpful articles from Roger Elmore share on corn planting windows where he used USDA NASS data to show Nebraska data and also shared how other states throughout the Corn Belt have found similar results regarding planting windows. The key point is there’s a planting window between mid-April to mid-May within which optimum yields are usually obtained. After this period, yields decrease rapidly. So there’s still time and the planting conditions play a role in determining final yield by getting that seed off to a good start. You also keep hearing me talk about planting soybean early. Even as early as you can in May is better than mid to late May for higher yields if that works for your situation.
Browning Evergreen Trees and Shrubs: This past winter was hard on many things. When it comes to evergreen trees, the deep frost line and extreme cold led to the inability for transpiring trees to uptake moisture. This resulted in needles appearing brown and looking dead, particularly on the north and sometimes west sides of trees. I’m seeing this particularly on junipers, cedars, arborvitae, white pines, and some spruce. We’d recommend waiting till June before pruning any dead portions out or removing any trees/shrubs to see what happens with new growth.
Rhizosphaera Needle Cast in Spruce has been really bad the past few years. If you’re seeing spruce needles on lower parts of the tree turning yellow/reddish-purple/brown, then this disease may be the problem. The fungus continues moving upward on the tree. Affected needles are prematurely cast from the tree. Above average moisture during the growing season in parts of the State led to an increasing number of spruces affected by the Rhizosphaera fungus. What’s interesting is that the fungus infects the needles in spring but the symptoms often don’t appear till the following spring. One way to double check is to look for tiny black specks on the needles and on the twigs. The good news is that fungicide applications of chlorothalonil (Fungonil, Daconil, Bravo) or Bordeaux mixture in May can help when shoots are ½ to 2” in length! If we get frequent rains this growing season, applications can be repeated every 3-4 weeks.
Vegetable Planting Guide: Gary Zoubek had put together an excellent vegetable planting guide for the area which can be obtained at the Extension Office or at: https://go.unl.edu/d7qk.
Spring Lawn Seedings: With the difficulty of this past year, many didn’t get dormant seedings on because of all the snow and typically lawn renovation in the spring is difficult because of the inability for applying crabgrass preventer to newly seeded areas. However, a new product has changed this! Scott’s Turf Builder Starter Food for New Grass contains mesotrione which provides PRE and POST control of weeds without affecting the new bluegrass or fescue seeding. We’d still recommending seeding as soon as possible or else wait till August. Tenacity is also a product containing mesotrione that works as a POST for emerged crabgrass, foxtail, and for those dealing with nimblewill (best to apply on troublesome grassy weeds up to 1” tall).
Rhubarb and Frost: For those impacted by frost/freeze this past weekend, if rhubarb leaves are not damaged too much and the stalks remain firm, it is still safe to eat. If the leaves are severely damaged or the stalks become soft or mushy, do not eat these stalks. Remove and discard them. New stalks can be harvested and eaten. Rhubarb often develops seedheads following cold temperatures, but this also does not affect eating quality of the stalks. Remove rhubarb seedheads and discard.
Planting Considerations: Everything we do at planting sets the stage for the rest of the year. We’re blessed to have equipment that can allow for many acres to be planted in a short amount of time. And, we have the ability to mess up a lot of acres in a short amount of time.
For soil conditions, it’s important that we’re not mudding in fertilizer and seed to avoid compaction and uneven emergence issues. Soil temperature information can be found at: https://go.unl.edu/soiltemp. It’s best to plant when soil temps are as close to 50°F as possible, check weather conditions for next 48 hours to hopefully maintain temps 50°F or higher, and avoid saturated soil conditions. If planting a few degrees less than 50°F, make sure to check with seed dealers on more cold-tolerant seed and only do so if the forecast is calling for warm temperatures the next few days that would also help increase soil temperatures. Once planted, corn seeds need a 48-hour window and soybeans need a 24-hour window when the soil temperature at planting depth does not drop much below 50°F. Otherwise chilling injury is possible.
With the variability of weather each spring, we perhaps need to shift our focus from “calendar dates” to “planting windows”. The optimum planting date for corn may not be in April every year. Research from Iowa State found optimum planting date windows to obtain at least 98% yield potential range from April 15-May 9 for northwest and central Iowa; from April 17 to May 8 for southwest Iowa; and from April 12-30 for north central and northeast Iowa. To achieve at least 95% yield potential, those ranges extend from April 15 to May 18 for northwest and central Iowa; from April 12 to May 13 for southwest and southeast Iowa; and from April 12 to May 5 for north central and northeast Iowa. It’s not Nebraska data, but could be considerations for us for similar areas of Nebraska. And, while we don’t have a lot of data in Nebraska, one can use USDA ag statistic yields and I’ve also used the Hybrid Maize Model to show how yearly weather can impact optimum planting windows for best potential yield.
Planting soybean early is critical to maximizing yield. Beyond genetics, this is the primary way to increase soybean yield through numerous University studies in addition to grower-reported data. Because of this, an increasing number of growers are planting soybean earlier than corn or at least at the same time as planting corn. ‘Early’ is within reason, though. While we’ve had on-farm research fields and many growers’ fields planted from April 22 and after (in good field conditions), be aware that crop insurance date is April 25. We also recommend adding an insecticide + fungicide seed treatment when planting in April as we have no data without seed treatment in our planting date studies.
Planting depth is also key. Aim to get corn and soybean in the ground 1.5-2” deep. This is critical for correct root establishment in corn to avoid rootless corn syndrome. While not as critical regarding root establishment for soybean, our UNL research showed lowest yields when soybean was planted 1.25” or less or 2.25” or greater with the highest yield at 1.75” deep. This is most likely because moisture and temperature were buffered, particularly when soybean was planted early. It’s important to get out and check seeding depth for all planter units within every field. Even with monitors showing down force and seeding depth, it’s still important to check. I’ve seen how adjusting down force can lift up planter ends resulting in shallow planting in the outside rows, particularly with center-fill planters. Results of improper/uneven planting depth can be seen all season long and may affect yields. While this takes time, you’ll be glad you caught any issues before too many acres are planted incorrectly!
For corn seeding rates, it’s best to check with your local seed dealer as all our research shows that optimal corn population varies by hybrid. However for soybean, our recommendation after 12 years of combined on-farm research studies continues to be: plant 120,000 seeds/acre, aim for a final plant stand of 100,000 plants/acre and you’ll save a little over $10/acre without reducing yields. If that’s too scary, try reducing your populations to 140,000 seeds/acre or try testing it for yourself via on-farm research! Please contact me if you’re interested in that. We have an article on our soybean seeding rate data in this week’s CropWatch at http://cropwatch.unl.edu.
Lawn Crabgrass Preventer and Fertilizer Application: Crabgrass is a warm season grass and needs soil temperatures to reach 55 degrees F for a few consecutive days to germinate. It doesn’t all germinate at once, thus the potential for a second flush in the summer. The targeted window to apply pre-emergence herbicides for crabgrass in eastern Nebraska is April 20 to May 5. Keep in mind that the product needs to move into the soil within 3 days or it will start breaking down due to sunlight exposure. You may also consider applying your crabgrass preventer with first lawn fertilizer application around the beginning of May.
Happy Summer! June 20th marked the start of the summer season. Summer means a good time for cookouts, picnics, swimming, and grub control. Not exactly what you had in mind for summer fun? Knowing the pest and its habits can help keep you from spending all of your summer fun time dealing with grubs.
In the landscape, October is the month to water, control weeds, and plant bulbs, trees and shrubs. It is also the month to wait until after a freeze to cut back perennial plants and wait for the soil to freeze before covering tender plants with winter mulch. Kelly Feehan, UNL Extension Educator, provides the following information.
Sometimes people ask if trees and shrubs should be watered at this time of year since their leaves will soon drop off; and how late in the season lawns should be watered. As long as the soil is dry, go ahead and water. Plant roots continue to grow long after leaves drop off trees and shrubs and after grass stops growing. Roots, rhizomes and stolons can grow well into November and fall watering promotes this growth helping plants recover from summer stresses. Plant energy can be used for root growth during fall since energy is no longer needed for leaves, flowering or seed production. Roots continue to grow until soil temperatures drop below 40 degrees Fahrenheit with available moisture.
Water enough to moisten the soil to a depth of about eight to twelve inches for trees and shrubs and six inches for lawns. Keep in mind that a lack of oxygen due to a saturated soil is just as damaging to roots as a lack of water. Allow the soil to dry between watering.
Because roots continue to grow well into fall, September through October is a good time to plant deciduous trees and shrubs. For spring flowering bulbs, wait until soil temperatures drop to 60 degrees Fahrenheit to plant.
A common question asked about fall planting is if a starter fertilizer needs to be used at planting time. Starter fertilizers are high in phosphorous, a nutrient important to root production. The only way to know the answer to this question is to have a soil test taken. However, most landscape soils are high in phosphorous (P). Fall soils are often warm and dry which makes P more readily available. In most cases a starter fertilizer does not need to be used during fall planting.
More important is to plant at the correct depth. With bulbs, follow label directions for planting depth. It varies depending on bulb size. Some recommendations say to plant about one to two inches deeper than recommended. The opposite is true for trees and shrubs. Before planting trees, locate where the trunk flares out at the trunk base then plant at a depth so the flare is visible above ground. Do not loosen the soil beneath the root ball or the tree may settle and end up planted too deep. In heavier clay soils plant so the trunk taper is one to two inches above the ground.
October is the best time to control perennial broadleaf weeds like dandelions, ground ivy and clover. There is no ideal time during fall to apply lawn weed and feed products together. The best time to fall fertilize lawns is in early September and again in late October or early November. The best time to apply herbicides for lawn weeds is about mid-October before a hard freeze.
Weed control can be more effective and less herbicide will be applied where it is not needed by avoiding the use of combined weed and feed products during fall. One can achieve better weed coverage and control of established broadleaf weeds if the weeds are spot treated, typically with a liquid formulation of herbicide.
Here’s wishing you a great October of accomplishing landscaping projects!
This past week was a blur of calls, questions, and visits to homes and fields but it was a great week and flew by staying very busy! I’ll touch on a few of the common questions I’ve received this week.
Trees: Some trees such as willows, hackberries, tops of maple trees, ash, and black walnut are just taking time leafing out. Some trees leafed out once already and dropped leaves. Things that may have caused this were the sudden flux of temperatures from very warm to cool and the strong winds we received. Some trees have also unfortunately had herbicide drift damage that caused leaves to drop. On those trees, watch for new buds as nearly every situation I’ve looked at thus far have new buds forming after about a week-10 days. With all these situations, give the trees a few weeks to leaf out again and if they’re still not doing it, feel free to give me a call. Trees are interesting plants as sometimes environmental impacts that happened 3-5 years ago will show up that much later-and sometimes environmental impacts show up right away!
Disease/Insect issues: This year has been a strange year all around but with our warm winter, I was concerned about an increase in diseases and insects. Thus far, we’re experiencing increases in both-so hang on-it may be a long growing season! Our high humidity, warm temps, and heavy dews have created perfect conditions for fungal diseases on our trees, ornamental plants, lawns (I’m currently fighting a bad case of powdery mildew-as a plant pathologist it is kind of pretty but I don’t like what it’s doing to my lawn!), and in our wheat and alfalfa crops and some pasture grasses. Fungicides may help in some of these situations, increasing airflow can also help as can more resistant varieties or hoping the weather will change. In the case of most ornamentals, we don’t usually recommend doing anything. The same goes for insects as insecticides can help in some situations. I’ve received several calls this past week of people afraid they had herbicide drift damage. While there were a few cases of that, many of the cases were actually fungal leaf spots on leaves. There are various fungicides and insecticide products available from home/garden centers, etc. Be sure to read and follow all label directions and only apply the product on places the label specifies it can be applied.
Crops Update: Later this week we may have a better idea on the extent of storm damage and if some fields will need to be replanted after the storms from last week. Dr. Bob Nielsen from Purdue University reported that most agronomists believe young corn can survive up to about four days of ponding if temperatures are relatively cool (mid-60’s F or cooler); fewer days if temperatures are warm (mid-70’s F or warmer). Soil oxygen is depleted within about 48 hours of saturation and we know soil oxygen is important for the root system and all the plant’s life functions. So we’ll have to wait and see what happens.
Have also had a few calls regarding rye cover crops. When rye is killed out and decomposing, it releases toxins that can affect the germination of other cereal crops such as corn if it’s going to be planted into that rye cover crop. Thus we recommend at UNL that the producer kill the rye and then wait at least two weeks to prevent any major damage to the crop. I realize at this point with the rains to get in and kill that crop on top of waiting an additional two weeks, we’re getting close to the end of the month and will most likely be looking at reduced yields…and depending on maturity, you may need to consider different seed if you end up having to plant in June. If you have specific questions about this, please let me know and we can talk through some situations.
Stripe rust and powdery mildew have been obliterating mid-lower canopies of many wheat fields. I’ve received several calls on why wheat canopies are yellow-that’s the main reason but other factors such as the dry spell prior to these rains and/or deficiencies in nitrogen/sulfur or some viruses may also have been factors. Wheat in Nuckolls County last week was beginning to flower. Fungicides such as Prosaro, Folicur, or Proline are labeled for up to 50% flowering and cannot be applied after that. Remember the wheat head begins pollination in the middle-so if you’re seeing little yellow anthers at the top or bottom of that head, you’re towards the end of flowering. All those products have a 30 day pre-harvest interval-which has been the other main question-are we going to be harvesting in a month? I do believe we’ll be harvesting a month earlier than normal just because pretty much everything in wheat development is about a month ahead of schedule. I still feel the 30 day window for the fungicide application is worth it with the large amount of disease pressure we’ve seen. Wheat in Clay Co. and north still may have time for a fungicide application; those products mentioned above will help prevent Fusarium Head Blight (scab) as well as kill the fungi causing disease already present on your leaves. A list of all fungicide products, pre-harvest restrictions, and rates can be found here. Also check out my previous blog post with video on scouting for wheat diseases.
The other major disease appearing in wheat is barley yellow dwarf virus. This is a virus vectored by bird cherry oat aphids which we were seeing earlier this year. Unfortunately, this disease causes the flag leaves to turn bright yellow-purple causing yield loss (at least 80% of the yield comes from the flag leaf) as there’s nothing you can do once the virus manifests itself in those leaves. If you have a large incidence of barley yellow dwarf in your fields, you may wish to reconsider spraying a fungicide as the fungicide won’t kill the virus; however, it will help kill the fungi on the remainder of your leaves and potentially help protect some yield from the two leaves below the flag leaf.
I really appreciated Gary Zoubek presenting at our lawn care workshop last Thursday! I also appreciated all the questions and good discussion; hopefully everyone walked away learning at least one new idea or tip!
One common question was what to do with areas that were killed out by summer patch last summer. Summer patch is a fungal disease that is favored by applying nitrogen too early in the spring, by a compromised root system by too wet of soils in the spring, by stress from summer heat, and irrigating in the evenings. Last year I was receiving calls from all over the County regarding this disease. Eventually affected areas can refill, but in many cases, that just didn’t happen. Preventive fungicides right now are recommended to help prevent the fungus from causing damage to your lawn again this summer.
So besides a preventive fungicide what can you do? The best time to reseed is actually in the fall. One option is to keep these areas weed-free including of crabgrass so that doesn’t overtake these areas. Reseed with a disease resistant variety in the fall following the recommendations in this extension circular.
Your other option is to reseed/overseed right now with a disease resistant variety knowing that you may fight crabgrass this first year. Overseeding and reseeding are recommended to occur from now through May 1 for Kentucky bluegrass and from now to early June for tall fescue. You can determine the correct timing of all lawn practices by visiting the turf calendar Web site. Simply choose whether you have Kentucky bluegrass or fescue. Click on a lawn practice and scroll the circle on the calendar area to the current month to find the recommendation for that time.
Some other tips regarding lawn care: sharpening lawn mower blades is key to not shredding the grass which can invite pathogens that cause disease; mulch lawn clippings as often as possible as they contain nitrogen that can be released back into the soil; use a fertilizer product with the highest amount of a slow release nitrogen as possible (check fine print on the fertilizer bag); and sweep or use a leaf blower to send all clippings and granular pesticides back onto the lawn as leaving them on the sidewalk allows for them to be washed into the gutters and eventually lakes and streams. Right now, a silvery colored fungus called powdery mildew is visible in places in lawns that are shady or have minimal air movement. We don’t typically recommend a fungicide as this disease is more aesthetic than harmful.
Here’s wishing you a nice lawn this summer! Also a reminder of our free Container Gardening workshop to be held April 19th from 5:30-7:00 p.m. at the Clay County Fairgrounds. Elizabeth Killinger, UNL Extension Educator, will be presenting on container gardening for vegetables and flowers, creating a few container gardens for door prizes, and provide creative ideas for container gardening. Please RSVP at 402-762-3644 so we can have a meal count, hope to see you there, and invite your friends!
Happy April! The weather sure has been interesting! Since my last columns, UNL has come out with some altered recommendations for turf. So letting you know that according to Zac Reicher, Professor of Turfgrass Science, he is recommending an application at 50% of the high label rate rate of crabgrass control now in the form of dithiopyr and then plan on making a sequential application at 50% of the high label rate in early to mid-June with a dithiopyr product. Crabgrass is already emerging and this product helps with grass that’s already emerged as well as controlling crabgrass pre-emerge.
Also information from Zac: Preemergence herbicide applications for broadleaves can start anytime now and assuming typical weather, sequential applications should be planned for in June. Almost all of the current preemergence herbicides (dithiopyr, pendiamethalin, prodiamine) are available as fertilizer/herbicide combinations, but cool-season grasses need little nitrogen in the early spring regardless if it is in March this year or late April in most years. Therefore, it is important to use a herbicide/fertilizer combination with as little nitrogen as possible to avoid a large growth flush and maximize long-term health of the plant. The problem is finding a product with little or no N. If you find a selection of products, do some quick math and calculate which product delivers the lowest amount of N/1000 sq ft, preferably 0.50 to 0.75 lbs N/1000 sq ft. Additionally, slow release N will extend the window of N release and minimize the potential growth spike after application. Slow release sources include sulfur- or polymer-coated urea, urea formaldehyde, methylenediurea, dimethylenetriurea, or natural organic nitrogen. These are listed on the label as “slowly water soluble” or “water insoluble”. Pay special attention to N sources followed by an asterisk and be sure read and follow the entire label of any product you apply. With the unusual weather this year and the increased need for sequential applications, each application usually applies about 50 to 75% of that which would be applied when using a single application. Applying two applications at lower rates will also reduce the nitrogen applied in each application, which is beneficial at this time of year.
The following sources explain more about the math calculations:
• Update: Warm soils and forecast are revising recommendations for preemergence herbicides
• Lawn Care Pro Series: Crabgrass and Other Summer Annual Grasses
• Do it yourself: Choosing preemergence herbicides
• Crabgrass Control in Homelawns
April 1st, while typically a day of pranks and jokes, has one obvious truth. Spring has arrived in full force with flowering plants at least 2-3 weeks earlier than normal. I couldn’t believe that my lilacs, which typically bloom around mid-May were blooming for the first time today! I planted many of the bulbs and shrubs last fall and have been rewarded with beauty, color, and lovely smells via God’s creation this spring; enjoy the pics!
Well, this weekend I mowed my yard for the first time this spring-hard to believe for March! For two weeks I’ve been advising people to wait on fertilizing or applying crabgrass preventer on their lawns. It’s hard for me not to stop my vehicle everytime I see someone using a lawn spreader right now and ask them to wait! It’s too early to apply pre-emergent herbicides and fertilizer. Wait another month (till at least April 20) before the first fertilizer of 1 lb/1000 sq. ft is applied. At that same time, pre-emergence herbicides can also be applied. Wait to overseed Kentucky bluegrass lawns till April 1 and Fescue lawns till April 15. You can check out a calendar of recommendations for all things concerning your lawn at the following site: http://turf.unl.edu/lawncalendars.cfm. When overseeding winter-killed areas, core aerate or power rake the lawn prior to overseeding to encourage seed to soil contact for better germination. Also, don’t apply herbicides to areas where you have overseeded as this will affect the germination of new seedlings.
A timely meeting for lawn care has been scheduled and you can learn more by attending a Lawn Care for Home-Owners meeting Thursday, April 12 from 5:30-7:00 p.m. There is no charge and light refreshments will be provided. Learn about fertilizer labels and timing, calibrating your lawn spreader; irrigation timing for lawns; and calendars for lawn care maintenance. Please RSVP to the Clay County Extension Office at (402) 762-3644 or email@example.com.
Garden: It’s been hard for me to resist the temptation to remove the winter mulch I had on my perennials and flower beds but in the event of frost which still is a good possibility, it may be good to leave it on awhile longer if new growth has not occurred. Kelly Feehan, UNL Extension Educator from Platte County advises if new growth is beginning to occur on your herbaceous perennials, to rake the leaves/mulch into a nearby pile. This allows the new growth to get acclimated to sunlight but allows the mulch to be raked back onto the growth in the event we end up with a cold snap.
I know some people have planted peas and potatoes. Check out the Vegetable Planting Guide that Gary Zoubek, UNL Extension Educator in York developed for suggested vegetable planting dates for our area: http://york.unl.edu/water-environment. Thursday, April 5th, Backyard Farmer returns for its 60th season on NET1 at 7:00 p.m.! Also, on Thursday, April 19th, we will have a workshop on Container Gardening Fun at the Clay County Fairgrounds from 5:30-7:00 p.m. More information to come! Please RSVP to firstname.lastname@example.org or (402) 762-3644.