ProHort Update for August 2026

1. Selecting Turfgrass Seed for Long-Term Success

The window for seeding cool-season turfgrasses is coming soon from August 15 to September 15, and success begins long before the first seed is sown. Seed quality, along with species and cultivar selection, can dramatically influence turf establishment and performance, so think ahead to invest in the right seed that precludes costly renovation or corrective management later. 

Start with the Right Grass Species

In Nebraska, species selection should be based on regional adaptation and site conditions. Kentucky bluegrass is generally recommended for lawns in western Nebraska, while turf tall fescue is preferred in eastern Nebraska. These species don’t tolerate shade very well, so consider incorporating fine leaf fescues into the mix for sites containing both sunny and shaded areas. For heavily shaded locations, professionals should consider alternatives to conventional turfgrass, such as low-growing sedges or shade-adapted groundcovers. 

More on species selection here from the University of Nebraska—Lincoln Turfgrass program.

Cultivar Selection

For professionals, blending different cultivars helps reduce risk and improve long-term turf resilience. A blend of three to four cultivars is generally preferable to a single cultivar and offers greater genetic diversity, improved disease resistance, enhanced environmental adaptability and more consistent performance under variable conditions.

The National Turfgrass Evaluation Program (NTEP) provides extensive performance data that can help guide cultivar selection. However, while hundreds of cultivars are evaluated through NTEP trials, only a fraction are typically available through local suppliers. Fortunately, reputable local seed dealers often pre-select high-performing cultivars adapted to regional conditions, simplifying decision-making for landscape contractors and turf managers.

Why Seed Quality Matters

Not all turfgrass seed offered for sale is equal. While lower-priced seed may appear attractive upfront, seed cost often reflects seed quality. A modest splurge on seed can pay substantial dividends through improved turf vigor and reduced maintenance inputs. This is because lower-priced seed can be older and often contains greater levels of undesirable species or lower-performing cultivars. At the very least, avoid seed sold from unidentified bulk bins and mixtures containing K-31 tall fescue, annual ryegrass, annual bluegrass and other coarse-textured pasture grasses.

Buy Certified and Identified Cultivars

Whenever possible, select seed that clearly identifies the grass species and cultivars included in the mix. Avoid seed labeled VNS (Variety Not Stated). 

High-quality seed certified by the Nebraska Crop Improvement Association can be identified by the blue certification tag. Certification confirms the authenticity and purity of the cultivar and requires standards that are more stringent than minimum legal requirements for purity, germination, weed seed, and crop seed contamination.

However, certification should not be confused with a guarantee of overall seed quality. End-buyers should still carefully review the seed label.

Learn to Read the Seed Label

The seed label, or tag, is a legal document that provides information on species and cultivar names, germination percentage, purity percentage, weed seed content, other crop seed content, inert material and seed testing date. Understanding these values allows buyers to compare products accurately and identify potential quality issues before purchase.

Check out this article from UMAss Extension showing what to look for on a seed label.

Pay Attention to Purity and Germination Percentage

Typically, lower-quality seed requires a higher seeding rate to achieve the desired stand. A high pure seed percentage coupled with a high germination percentage means that you don’t have to use as much, potentially saving you money on product. Look for seed where the total percentage of pure seed (not including other crop seed, inert matter, or weed seed) is over 90% and the germination percentage for any given cultivar is over 85%. Then you can apply it at the lower end of the recommended range without risking poor coverage. 

Look here for Nebraska’s recommended turfgrass seeding rates and other tips on fall seeding. 

Check Seed Freshness

Seed viability declines with age. Seed older than 9 to 12 months may exhibit reduced germination and vigor. Always review seed testing dates on the label and purchase recently tested seed whenever possible.

Remember: Seed Bags Contain More Than Seed

Grass seed bags may also contain inert material, weed seeds, crop seeds and nonviable seed. While small amounts of inert material can help with handling and seeding, excessive amounts mean that not much actual seed is in the bag. Careful review of purity and germination percentages helps determine the true value of the product.

Watch for "Other Crop" Seed

Another important section of a seed label is other crop seed content.

"Other crop" refers to species intentionally grown for agricultural or commercial purposes but not necessarily desired in the turf being established. Examples include orchardgrass, rough bluegrass, and bentgrass that can become permanent, hard-to-eradicate weeds.

Even contamination levels below 0.5% can create serious problems. (For example, a tall fescue seed lot containing 0.5% orchardgrass could introduce approximately 12 to 16 orchardgrass plants per square foot.) For high-quality turf installations, look for seed lots with 0.01% other crop content or less.

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2. July 28th growing degree days (GDD)

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3. Pest Update 

For a more complete list, visit Michigan State University GGD of Landscape Insects or GGD of Conifer Insects.

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4. Knowing Your Yard's Sun and Shade Patterns, K-State Research and Extension

A microclimate in a landscape makes a big difference in how a plant grows and thrives. Pay attention to sun and shade patterns through the year to determine what plants will grow best in the location. 

Read more here. 

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5. Flowering Groundcovers

Last month, the conservation recommendation focused on using grasses and sedges as a groundcover filler as opposed to yards of mulch. You may have been thinking to yourself, ‘My client likes to see flowers, though. Is there anything for that?’. Short answer: yes.

In addition to the various benefits of having plant material like grasses and sedges filling ‘empty’ spaces, flowering groundcovers offer plentiful resources for our pollinators and beneficial predatory insects. As discussed in the Winter Update, an increase in predators and parasitoids can lead to a gradual decrease in the need for some pesticides. Insecticides are a given – if you have predators hunting down pest insects or laying their eggs in/on them, you will have fewer infestation explosions. Another potential benefit is a decrease in soft-bodied insects like mites and aphids can decrease instance of fungal pathogens, either secondary in leaf wounds or problems like sooty mold growing on sugary honeydew, reducing the need for some fungicide applications.

All this goes toward less time and money spent on inputs and more ability to support a somewhat self-sustaining landscape. As mentioned in the update, sometimes it’s just a matter of having some of those conversations with clients about the benefits of less mulch and a slight tolerance of some insect damage – after all, you won’t have predators if they don’t have anything to eat.

Below are a handful of plants that will cover the ground nicely while providing a fun pop of color. Keep in mind that native perennials generally flower over a more specific period of time than annuals, and ‘groundcover’ is quite subjective – some of these plants may reach over 12” if they are happy, and flower stems can sometimes be 24” or more. Also, as with the grasses and sedges, you may have more luck with some species than others.

Annuals

Nasturtiums and lantana can get to be on the taller side depending on variety, but they fill spaces well and offer a wide array of both leaf features and flower coloration. They also tend to experience fewer pest issues than, say, petunias.

Marigolds are another option with lots of variety, though with a slightly smaller spread you will need more plants. Also consider verbenas and bidens for a low, spreading pop.

Perennials

For non-native perennials, I’ve always been a fan of ajuga and lady’s mantles. Ajuga is very low-growing with early season blooms and tends to be a pretty hardy spreader. Lady’s mantles is taller, but still around a foot or so and can handle a little more shade than ajuga.

Natives offer a wide range of sizes, seasonal blooms and character. Two perennial classics (no pun intended) are creeping phlox and sedum (not all are native, but that’s OK). A river of creeping phlox blooming in the spring is always a sure-bet show, and the foliage is interesting enough to be a good background for the surrounding plants the rest of the season.

Anemone (windflower) is taller, but will colonize very well, and when its white blooms open in spring it is quite a sight to behold. Missouri evening primrose is a reliable spreader and tough once established; a great pairing if you can find it is wild petunia – both will bloom throughout summer. Coreopsis is another good choice for yellow, but readily seeds out if defined borders are a must. Although it can be pretty aggressive, purple poppy mallow will cover the ground for sure and also cover some of its neighbors if given the chance. A great choice but will probably require some more maintenance.

Lastly, some fairly easy to find options are coral bells, foamflower and the hybrid of the two Heucherella. Coral bell and foamflower are hardy and adaptable natives in a wide range of coloration and a mass planting of any of these three looks great in a more partial shade setting.

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6. Mimosa Webworm

Mimosa webworm is a caterpillar that commonly feeds on honeylocust trees in our area. The caterpillars tie leaflets together with silk and feed within the webbing, causing the foliage to turn brown and giving the tree a scorched or ragged appearance. Damage can range from cosmetic to more extensive defoliation depending on the number of caterpillars and the overall health of the tree.

Some honeylocust cultivars are more susceptible than others. ‘Sunburst’ is particularly susceptible, while ‘Shademaster,’ ‘Skyline,’ ‘Moraine,’ and ‘Imperial’ are considered less susceptible. However, under high insect pressure, even these cultivars can sustain noticeable damage.

We typically see two generations each year, with the first appearing in early summer and a second generation late summer-early fall. The second generation can sometimes cause the most noticeable damage.

Management can be challenging once the webbing has formed because the silk is water-resistant and can prevent foliar insecticides from reaching the caterpillars. On smaller trees or where webbing can safely be reached, opening the webs with a stick or broom may allow natural predators better access. Small infestations usually do not require treatment. In some cases, clientele may reach out to you for assistance and management options for trees with severe or recurring infestations.

More information here.

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7. Japanese Beetles are Still Feeding

Japanese beetle are still out and actively feeding on a wide range of plants. Many of our clients are asking what can be done with so much damage. Sadly, at this stage all that we can really do is remove by hand. Beetles can be active up to 45 days after emerging from the soil and they don't all emerge at once. A non-traditional option to help reduce damage and making feeding sites less favorable would be the use of kaolin clay found in the product Surround WP. It should be used as a preventative and not a curative product. Surround will coat the plant with a light glaze of clay. This can create a physical barrier making it harder to land/cling/feed. It will visually change the appearance which could confuse the beetle and have it go elsewhere.

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8. Fall Webworm

Fall webworm is a common pest on deciduous trees in the fall. Caterpillars are found on the ends of the branches within a mass of webbing they create around themselves. Fall webworm shows up in late August to September on many species of deciduous trees including elm, hickory, pecan, plum, chokecherry, poplar, walnut and willow. In fact, almost all fruit, shade and ornamental trees, except conifers, can be affected by fall webworm. Many people think they should cut out infested branches, but fall webworm isn't harmful to trees and no management method is necessary, pesticides are not effective because it cannot penetrate through the webbing to the caterpillars. The damage is unsightly, but will not harm the trees it is found in. If homeowners do not like the look of the webbing in their trees, they can remove the webs with a broom, putting the web and caterpillars into a bucket of soapy water once removed or spray the webs with a strong spray of water to knock it out of the tree. 

More information here  

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9. Winter Annual Weed Control in Turf
 

Pre-emergence herbicide should be applied by early September for control of winter annuals like annual bluegrass, downy brome, henbit, little barley and speedwell. Winter annuals will soon be germinating and pre-emergence herbicides should be in place before germination begins as they kill seedlings after they germinate. Common landscape pre-emergent herbicides include bensulide (Bensumec), dithiopyr (Dimension), oxadiazon (Ronstar G), pendimethalin (Pendulum) and prodiamine (Barricade). Other management options for winter annual weed control includes maintaining a healthy and vigorous growing lawn or landscape bed plant cover to crowd out weed invaders. A layer of organic mulch 2-3 inches thick will also minimize weed germination in the landscape bed.

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10. Commercial/Non-commercial pesticide applicators

If you have a pesticide applicators license which expired in April 2026 or you need to get a new license, testing options are listed below.

Testing-only Options

• Closed-book exams are given by the Nebraska Department of Agriculture (NDA). Preregistration is not required an there is no cost. Visit the link below for a list of available test-only dates, times and locations - https://pested.unl.edu/.
• NDA computer-based testing is provided through the Pearson-Vue company. Click here for a list of testing sites, categories available, dates, and registration information. Cost $55 per exam. (For applicators with multiple categories on their license, each category is charged the full testing fee.)

Commercial/noncommercial applicators are professionals who apply restricted-use pesticides for hire or compensation. Anyone who applies pesticides to the property of another person, either restricted- or general-use products, for control of pests in lawns, landscapes, buildings or homes must also have a commercial pesticide applicators license. Public employees (those employed by a town, county, state) applying mosquito control pesticides whether restricted- or general-use, must also hold a commercial or noncommercial certification.

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11. Digital Diagnostic Network - Need help with diagnostics?

Do you or your clients have questions you need help answering? Maybe you are a lawn care person and they're asking about trees, shrubs, or flowers? While you can refer them to their local Extension office, another option is Digital Diagnostic Network. Homeowners, lawn care professionals, pest control operators and others are invited to submit questions and photos through this website or with the assistance from an Extension professional at any Nebraska Extension office. All offices are equipped with high-resolution digital image capturing technology. Whether the question is about a lawn weed, insects on a plant, diseases in a shrub border or other, an expert panel of Extension professionals will review and respond to the question. To get started, create an account so the question can be reviewed and responded to via email. For more information and to create an account, go to Digital Diagnostic Network.

Bugging Out With Your Camera Phone - Tips on how to get a good picture.

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Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by Nebraska Extension is implied. Use of commercial and trade names does not imply approval or constitute endorsement by Nebraskas Extension. Nor does it imply discrimination against other similar products.