ProHort Update for November 2026

1. Contact or Systemic...Which is Better?

Imagine a situation where your customer has a pest problem…not tough to do, as it’s a daily occurrence for most turf and tree managers.  The commonsense approach of Integrated Pest Management (IPM) will guide you through the control process.   

First, identify the pest…aphid, anthracnose, cedar apple rust, goosegrass, etc.  Next, consider threshold…the number of pests present that could possibly cause unacceptable damage.  If lots of pests are present and the threshold is exceeded, then consideration of the control method or combination of methods is next.  For best results, it’s wise to utilize more than one.  For example, if a crabapple tree is infected with apple scab, these cultural and chemical should be implemented or at least considered: 

• Selection of a disease resistant cultivar 
• Frequent inspection to monitor the development of the disease 
• Locating the tree in an area where moderate air flow exists 
• Locating the tree in a landscape bed rather than in the middle of a turf area 
• Avoidance of overhead irrigation 
• Inspection for and possible removal of crossing limbs, closely parallel limbs and sucker shoots 
• Judicious and timely applications of a fungicide 

But, then what?  If it comes to applying a pest control agent, should it be contact or systemic?   The answer is: neither…it depends.  The question of whether to use a contact or a systemic is similar to the question of whether rock/inorganic mulch is better than wood chip/organic mulch. Both types of mulch have pros and cons. Each landscape area should be analyzed separately and individually chosen based on the conditions of the site and the goals for the site. 

A systemic pesticide is one that is absorbed by the leaves, stems or roots and moves within the conductive vessels inside the plant to untreated tissues.  Systemic herbicides such as Trimec are absorbed by the leaves and move in the plant to kill the leaves, stems and roots.  They may kill weeds with only partial spray coverage.  Some systemic pest control agents move only in one direction within the plant, either up or down.  Knowing which direction the pesticide moves will help guide the selection process.  Some pesticides are considered to be locally systemic, and will move only a short distance from the point of contact. 

A contact pesticide is neither absorbed into the plant nor moved through the plant.  As the name implies, it functions on the outside leaf, bark or stem tissues by direct connection with the insect, weed or disease pest.  To be effective, the pest control agent must completely cover the pest.  An even, uniform application technique will greatly increase the chances of success. Depending on where the pests are located, control with contact pesticides can be difficult.  Applications of a contact pesticide to aphids, thrips, or spider mites on roses often fail because the pest feeds either under the leaf or in tight locations of the flower or nodes. 

In addition to pest identification, threshold establishment and following the IPM protocol, several other factors are helpful to consider when choosing. 

Location.   Location is just as important for landscape management as it is for real estate.  Let’s face it – as a turf/landscape manager, you don’t always get to choose the location of various ornamental plants in the landscape.  They may be on a slope, near a parking lot, along a sidewalk or driveway…all of these make a difference which action you choose.    

On a slope, the first concern is runoff, especially if a large volume of spray tank material is necessary.  Though both contact and systemic pesticides have potential to move to non-target areas, systemics may have a greater capacity for damage due to root absorption by adjacent plants on the downward side of the slope.  On the other hand, because it’s usually necessary to obtain complete coverage with a contact pesticide, stability and footing for the applicator may become a problem. 

Another location where this choice is pertinent is when the suckers of a small tree have become objectionable or when weeds are growing near other desirable plants.  In these scenarios, a contact herbicide may be the better choice because of the lack of off-target foliage and root absorption.  Obviously, extreme caution must be taken to avoid uptake by the photosynthetic portions of the tree bark or the foliage of nearby plants, yet this remains an advantage nonetheless. 

Limited Root System.  When trees, shrubs or flowers are growing in a limited or stressed root system, a contact product might be better because of the decreased capacity for root uptake.  This is common in both residential and commercial landscapes.  Homeowners routinely select plant material based on impulse, that which looks good at the large box store they happen to be at on a Saturday shopping spree.  Landscape designers often know better, but are sometimes pressured to plant the wrong plant because the client thinks they know better. 

Contacts may also be more favorable for trees that have been scarred or have damaged bark and stems, due to the limited capacity for movement in the phloem and xylem.  In certain other situations however, if the plant is located in a parking lot island planting, near important non-target objects such as cars, root applied systemics should be considered to avoid drift.  It is generally advisable to avoid ruining the paint job on a new Porsche or Jaguar. 

Price.  It some situations, several product choices of each type may be available and work equally as well to control the pest, but one might less expensive.  For example, when controlling a wide variety of weeds on non-critical areas such as an alley or between pavers, a “contact, non-selective burn it off type product” might be a better choice than the latest 4-way combination controlled release systemic.  Of course, the other often forgotten aspect of price is the component of the cost of the labor to apply a pesticide.  Time spent mixing, calibrating, cleaning equipment after application and re-application to take care of skips and gaps in coverage should also be considered.  Price should be thought of as one piece of a jigsaw puzzle of factors that lead to a pesticide choice.  As the old saying goes, “you get what you pay for”….and sometimes less. 

Finally, the selection of a product may be limited by availability.  For some pests, all options are either contact or systemic.  In the long run, the choice of systemic or contact should be thought of as one of many other factors to take into account to achieve good pest control.  Consideration of all available forms of control, plant choices and site factors will lead to customer satisfaction and profitability for turf and landscape managers. 

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2. October 29th growing degree days (GDD)

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4. Dormant Lawn Seeding, Nebraska Extension

If a customer’s lawn is thin from the ravages of summer and you didn’t reseed it for them in September, consider a dormant seeding in late November or early December.  Prepare the seedbed as you would for traditional seeding then use a drop spreader to put the seed in contact with the soil.  The goal is not to get it to grow this fall, but to put it in place so that it’s ready to germinate and take root with the first few warm days in April.  Selective preemergence products such as topramezone and mesotrione can be used in mid-April to curb crabgrass, foxtail and annual broadleaf growth.  Read and follow all label instructions.

Read more here

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5. Winter Container Gardening

In the late fall and winter months landscapes become drab and limited in color. In most cases, container gardens have been cleaned up for the season, but there is another way to use those containers in the winter by utilizing plant material for a winter container. Many evergreen plants can be used in the planter, either from cuttings or as actual plants in the container, if they are hardy enough to survive. Incorporate plants like red twig dogwood, American holly, winterberry, ferns, or bittersweet and use branch cuttings from pines, spruces, or firs. Anything that provides lasting visual interest even through freezing weather is a great addition to any container to brighten up front door areas for your clientele. You can even add holiday objects such as ribbon, twine, or different sizes of Christmas bulbs for a pop of color. 

Read more here

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6. Recycle Plant Debris

Help your customers to visualize their tree debris as a resource rather than a waste product.  It can be composted for future soil incorporation, used as winter mulch in strawberry beds or chewed up with a mulching mower for a light late fall fertilizer application.

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7. Check Soil Moisture through Winter

Check soil moisture frequently near newly planted trees and shrubs. Use a screwdriver or piece of ree bar to determine whether the soil is dry, moist or soggy.  Test the soil near the trunk, then 3 and 5 feet away from the trunk.  The goal is to keep the soil moist in fall and winter.  If found to be dry, add water slowly and allow it to soak in for a few hours, then re-test.

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8. Inspect the Bare Tree Canopy

As leaves fall from broadleaf trees, they leave a bare canopy, which provides a great opportunity to see issues such as crossing limbs, storm damage, cankers and other maladies.  Be sure to point these out to your clients and schedule pruning for late winter or early spring.

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9. Consider Anti-Desiccants

Consider anti-desiccant applications for broadleaf evergreens such as holly, Oregon hollygrape, boxwood and arborvitae. There are several pros and cons to their usage.  On the plus side, they reduce moisture loss from the leaves when the plant is least able to replace it from the soil.  On the downside, they clog up the stomates, interrupt respiration and reduce photosynthesis.  In many situations, new plantings and ones in wind-swept areas are usually the ones that are good candidates for anti-desiccant products.

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10. Reflect in the Off-season

Early winter is a great time for reflection and projection to the next year.  It’s often prudent to ask yourself the question “How Can I Be a Better Horticulture Service Provider to My Clients?”

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11. 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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12. 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.