Horticulture 2023 Newsletter No. 43

KSRE - Horticulture News



Blog Post: http://www.ksuhortnewsletter.org

Video of the Week: Will Fall Mums Last Through the Winter?



K-State Garden Hour: Plants Gone Wild! Controlling Invasive Plants

Wednesday, November 1, 2023, 12 pm – 1 pm CST

Given the opportunity, certain plants can take over your landscape, woods and pastures. Join Lynn Loughary, Wyandotte County Extension Horticulture Agent, as she helps you to know which plants to keep a close eye on. Learn about a few of our most invasive plants and management strategies for their control. Discover which weeds are also regulated by law, through Kansas’ noxious weeds program.



Kansas Turf & Landscape Conference

The 73rd Annual Kansas Turf & Landscape Conference will be held on Wednesday, November 29 and Thursday, November 30 at the Hilton Garden Inn, Manhattan. The conference is an excellent way to learn about turf and landscape management, visit with old friends, network with new ones, and see all the latest products and supplies from local and national vendors.

The conference has been approved for commercial pesticide recertification hours:

1 Core hour

3A – 7 hours

3B – 7hours

GCSAA education points and International Society of Arboriculture CEUS will also be available by attending the conference.

For more information, go to https://www.kansasturfgrassfoundation.com/


Dig cannas, gladiolas, dahlias and other tender bulbs for winter storage.
Spray for winter annuals such as henbit and chickweed as well as dandelions in the lawn.

Apply Late-Season Nitrogen Application in November

Although plant growth is slowing as the temperature drops, grass continues photosynthesizing. Applying nitrogen now boosts the photosynthesis rate and increases the amount of carbohydrates the plants can store through winter. This results in hardier plants with increased root growth and shoot density. Carbohydrates not used for immediate plant growth are stored for later use. Turfgrass with carbohydrate reserves can green up earlier in the spring and continue growth into May without additional fertilizer applications. This is beneficial because early-spring nitrogen applications tend to promote excessive shoot growth and reduced root growth.

For fall nitrogen applications, 1 to 1-1/2 pounds actual nitrogen per 1,000 square feet of lawn area is sufficient. Use a soluble nitrogen carrier such as urea or ammonium sulfate so the fertilizer is quickly available because the growing season is winding down. Many turfgrass fertilizers sold in garden centers and other retail outlets contain soluble nitrogen which work well for a November application. Avoid products that contain water-insoluble nitrogen (slow release) and clean up any fertilizer that scatters on the surrounding driveways, sidewalks or streets. (Cynthia Domenghini)



Garden Mums

Garden mums (Chrysanthemum) that have finished flowering can be cut back to two to three inches. Apply a layer of mulch over the top for protection through the winter. It is also okay to leave the top growth intact through winter. This can provide some insulation for the crown, but some gardeners prefer to tidy up plant material that has died back. Regardless of fall maintenance practices, garden mums should not be allowed to dry out during the winter. If there has not been any precipitation in the form of rain or snow, it may be necessary to apply supplemental water. (Cynthia Domenghini)



What to Do with Tree Leaves

Keeping up with leaves dropping onto the landscape is a big job every fall. The amount of leaf cover has an impact on the underlying plants. Photosynthesis will be restricted in a lawn covered with a dense layer of leaves preventing it from storing enough energy to survive winter. Here are a few options to deal with the beautiful mess.

Leaves can be added to the compost heap but it is best to shred them first. This can be done by mowing over them on the lawn and collecting them in the mower bag. They can also be added directly into the planters. Incorporate two- to three-inches of shredded leaves to the soil at a time. This can be repeated until the leaves are gone or the soil is frozen and cannot be worked. Shredded leaves can be used as mulch around trees, shrubs and perennials as well.

The shredded leaves can be left on the lawn if they are not too dense. If you can still see the lawn through the leaves overtop it should be safe to use this option. As you mow, the leaf pieces will fall in between the blades of grass and eventually break down into the soil. It may require multiple passes with the lawn mower to get the leaf size small enough. It is also necessary to mow frequently to keep up with the leaf drop. Some benefits of this approach have been reported in research. Leaf mulch incorporated into lawns can help prevent weeds from germinating between grass plants. Leaf mulch has not been shown to negatively effect on turf quality, color or soil pH.

If you are incorporating leaves into a cool-season lawn, it makes sense to be on a fall nitrogen fertilization program and core-aerate in the fall as well. You can mow leaves into a warm-season lawn, but wait to fertilize and core-aerate until late May or early June. (Cynthia Domenghini)


Recycling Pumpkins

As decorative pumpkins pass their prime due to time or freezing temperatures, put them to good use.
Pumpkins can be cut into small pieces and buried beneath leaf mulch in planters. Due to their high-water content, pumpkins will decompose relatively quickly and contribute organic matter back into the soil. Remove the seeds before composting to avoid growing an unwanted pumpkin patch in this location next year.

The raw seeds can be gathered and roasted for human consumption, or incorporated into feed for birds and other wildlife. Squirrels, deer and other animals will appreciate the meat of the pumpkin as food becomes scarce elsewhere. Farms and zoos will sometimes accept pumpkins from homeowners to feed to their animals as well. (Cynthia Domenghini)



Cynthia Domenghini, Instructor & Horticulture Extension Specialist

Ward Upham, Extension Associate

Department of Horticulture and Natural Resources

1712 Claflin, 2021 Throckmorton

Manhattan, KS 66506

(785) 532-6173


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Kansas State University Agricultural Experiment Station and Cooperative Extension Service K-State Research and Extension is an equal opportunity employer. Issued in furtherance of Cooperative Extension Work, Acts of May 8 and June 30, 1914, as amended. Kansas State University, County Extension Councils, and United States Department of Agriculture Cooperating, Ernie Minton, Dean.



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