ProHort Update for November 2025

1. Prepare Plants for Winter Storms

As fall continues, we are reminded of how soon winter will be here, including the possibility of snow, ice, and wind. Many times, trees and shrubs are damaged from winter weather, but we can prepare our plants for bad weather to help reduce damage seen through winter storms. 

Preventative Actions 

There are many great ways to prevent damage from ice storms before they occur. Maintaining correctly pruned trees is a great way to combat damage from storms. At this point in the season, wait until plants are fully hardened off before executing any tree pruning. Fall pruning often stimulates new growth or delays dormancy, which causes the plant to be more susceptible to damage from freezing temperatures. Limit pruning after dormancy, later this fall to those branches that need to be removed to reduce possible winter storm damage to trees. When pruning, remember to follow recommended pruning practices from the University of Nebraska, Nebraska Arborists Association, and the International Society of Arboriculture to ensure overall health of your trees.  

• Prune trees correctly when they are young to develop strong branching patterns and to avoid decay injury from branches removed that are too large.  
• Avoid topping, rounding off or pollarding pruning on trees. These practices result in weakly attached sucker branches that break easily in storms.  
• Remove dead, damaged, or diseased branches and remove them correctly at the branch collar, do not leave stubs.  
• Do not allow codominant or V-shaped trunks to develop on shade trees, these easily break in storms or with heavy ice development.  
• Select and plant trees with dense wood and strong branch angles that are less susceptible to breakage. Consider slow growing trees over fast growing trees which provide stronger branching habits.  
• Avoid staking trees too high on the trunk and remove staking materials after one year. The staking equipment should be flexible to allow the tree to move and develop roots to hold it in place in storms.  

Always be sure to select plants that are adapted to the hardiness zone you live in. In Nebraska it is zone 6 for southern Nebraska, zone 5 through the central portion across Nebraska, and zone 4 in northern Nebraska, check your hardiness zone map from the USDA. Always monitor your trees for signs of decay or other injury to avoid damage before it becomes a larger problem in the health and stability of the tree. Look for fungal growth on bark, discolored wood, and large wounds. Think ahead and maintain properly planted and pruned trees and shrubs to avoid damage from ice injury to plants. 

Plant Care After Ice 

When winter storms damage our plants, good plant care is encouraged following snow and ice events. Make sure the plant is kept well-watered when rainfall is not present. Keep soils around the plant evenly moist, not soggy and not dry. Water trees once a week during the summer by using a sprinkler at the base of the tree or use a hose at a slow trickle to get water down to 12-18 inches deep, which is the depth of the majority of tree roots. Shrub roots are down 8-12 inches deep, so ensure moisture that deep around shrubs. Test for soil moisture with a long screwdriver prior to watering to determine if watering is needed. If the screwdriver goes into the soil easily, watering is not necessary. However, if pushing the screwdriver into the soil is very difficult and the blade is dry after removal, plants should be watered. 

Trees and shrubs benefit from winter irrigation as well. Water plants once a month, as needed when snowfall or snow cover is not present. Winter irrigation should occur on days when temperatures exceed 45 degrees Fahrenheit and irrigate around noon to allow soils to thaw prior to irrigation and for the water to penetrate into the soil before the soil freezes again at night. Always remember to unhook hoses when finished irrigating in winter months.  

Maintain a mulch ring around all trees and shrubs to help reduce weed competition, moderate soil temperatures, and maintain moisture levels around plants. Organic mulches such as wood chips and pine needles are the best mulches to use, inorganic mulches do not hold moisture around plants and can be hot on roots and reflect heat back on plants. Mulch rings should be 2-3 inches deep at a uniform depth, do not mound mulches around the base of the plant.  

Avoid fertilization to plants injured from ice damage until the plant recovers. Fertilizers can push plant growth which can further stress them after the stress of ice injury.  

Top

2. October 29th growing degree days (GDD)

Top

4. Herbicide Carryover and Planting Bare-Root Tree Seedling in New Windbreaks, South Dakota State University

Windbreaks are constantly in need of renovation or complete overhaul. However, getting those new seedlings established could be more difficult when herbicides are used. When converting cropland or pastures to a new windbreak or even windbreaks up next to these locations could have impacts from herbicide carryover that is longer than previously thought. Read more for information on residual activity of many commonly used herbicides to bare-root tree seedlings in windbreaks. 

Read this article for more information

Top

5. Leaves are not Trash

We know that mulching grass clippings into the lawn can return up to 1 pound of nitrogen to the turf over the course of the growing season. Did you know that mulching leaves back into the turf during the fall can return up to 3 lbs of nitrogen, 0.46 lbs of phosphorus and 1.49 lbs of potassium per 1,000 square feet (Wallace, Vickie UConn Extension). Some authors suggest that mowing in leaves in the fall could be a replacement for fall fertilizing/winterizer. 

Michigan State University has been studying the effects of mulching leaves into the turf for the last twenty years. Their studies have shown that there is no damage done to the turf and saw an overall improvement. One such study showed that mulching maple and oak leaves saw a reduction of the weeds in the turf primarily the dandelion. 

Shredded leaves will not contribute to thatch build-up.

Up to six inches of leaves can be mulched into the lawn. Most push mowers are not designed to handle that much material. It is recommended that up to two inches of leaves to be mulched in at a time. Multiple passing may be needed to shred the leaves. It is common to still see leaf material at the top of the turf up to a day afterwards as it settles down into the turf canopy. 

Depending on the situation and leaf material access leaves can be mowed and bagged and used a mulch in the landscape. Generally speaking using whole leaves isn't the best choice for mulching. Leaves can layer like a pancake and reduce water movement leading to possible water damage to plants. Whole or shredded leaves can be spaded into the vegetable garden. 

Yardwaste nationwide contributes to 1/5th of the total amount of landfill waste. Bagged leaves make up one third of that amount. 

Leaf Disposal and Mulch Mowing from University of Connecticut 

Top

6. Apply a Preventative Fungicide to Lawns with a History of Snow Mold

In most Nebraska landscapes, snow mold does not cause injury at a sufficiently serious level to justify a preventative fungicide application.  Sports and golf course turfs are an exception, where even a minor to moderate amount of injury must be avoided.  Others include high value residential turfs such as estates and some bank, insurance and attorney properties.  Perhaps the most important and key justification category are turfs with a history of repeated snow mold injury.  In most cases, judicious use of preventative fungicides is effective and warranted.

Snow Mold from Penn State Extension

Top

7. Clean out and Store Spray Equipment. Fix Broken Parts.

Once final operations have been completed for turf and tree management for the year, it’s time to turn the attention to cleaning, repairing storing spray equipment and tools.   Taking inventory of partially and unused pest control products and fertilizers should be added to this winter activity.

Repairing Spray Equipment for Winter Storage and Spring Startup from Purdue Extension

Top

8. Rip up and Compost All Annual Flowers

Annual flowers such as pansies, geraniums, vinca, dipladenia and lantana add so much to landscapes in terms of color, layering and texture.  They provide the opportunity to put a big smile on your client’s faces when they see the results of your hard work.  However, when they succumb to the first killing frost, it’s time to dig them up and toss them into your compost pile. 

Putting your Flower Garden to Bed from Iowa State University Extension and Outreach

Top

9. Delay Pruning Trees and Shrubs until March and April

Pruning in the fall is not recommended, as plants are going dormant. Trees and shrubs are able to close pruning wounds much faster in spring due to greater meristematic capacity.  As well, fall pruning often stimulates new growth or delays dormancy, which causes the plant to be more susceptible to damage from freezing temperatures. Wait until early spring, when the coldest part of winter has passed, to do any major pruning. 

Planning Your Garden Pruning from Lancaster County Extension

Top

10. Prepare Tea Roses for Winter

The key to good rose protection is to not to get into a hurry to do it and until they are dormant.  A good indicator is when most to all of the leaves have fallen off the canes, and the canes themselves turn a bit off color. Temperatures should be in the 20's in a consistent pattern for several days.  Doing too much, too early will cause them to be injured in winter, in spite of good intentions.

Once they’re dormant, cut them back.  Tea roses should be cut back to about 30 inches or so, while miniatures only slightly. Floribundas and multifloras should be thinned and cut back severely.  Cover the rose canes with wood chips, corn cobs, sawdust, pine needles, or pine cones. You will need to use at least a bushel basket of materials for each rose bush.  Keep applying the covering material periodically, as Midwestern winds tend to blow it away.

Keep the material in place as long as possible with a rose collar.  Another option is to look around your store room and find a large box.   Open the bottom, slide it over the rose bush and then fill it up with wood chips.  You can seal the top or not, depending how it looks to you and your client. Additional pruning will be required in April as they come out of dormancy to removed the winter killed portion of the stems.

Climbing roses need to be taken down off the trellis and thinned.  Strive to keep about 4 to 5 of the strongest canes.  Older, broken and diseased canes should be removed at ground level.  Dig a trench near the base of the canes and bend the remaining canes into the trench. Cover the canes with the covering materials for tea roses.  Mound up the material to the same height as for tea roses.  In spring, carefully dig them up and reattach them to the trellises.

Top

11. Water Newly Planted Trees and Shrubs

Fall is for planting, which means that you probably have lots of new trees and shrubs in the landscapes of your clients to care for.  Two guiding principles apply to new and older woody plants alike – 1. Keep the roots moist, not soggy or dry and 2. Water to the bottom of the roots.  Digging a hole near the new roots to estimate soil moisture and using a stiff metal rod as a probing tool will help determine if it’s time to water (or tell the client to water).  A soaker hose is a great tool to use for watering new plants, as it directs water to the base of the plant without allowing much in the way of runoff.

Watering Newly Planted and Young Trees and Shrubs from Kansas State University

Top

12. Commercial/Non-commercial pesticide applicators

If you have a pesticide applicators license which expired in April 2025 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 and 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.)

2025 Commercial/non-commercial training was held from January through April. Training schedules are available at https://pested.unl.edu/. Help your employees be successful at getting a license by purchasing study materials. 

Top

13. 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.

Top

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.