Horticulture 2023 Newsletter #42

KSRE - Horticulture News




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


Video of the Week: Cleaning Extends the Life of Garden Tools




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/



Plant garlic if you haven’t yet.
Remove dead annuals after killing frost.


There is Still Time to Plant Spring-Flowering Bulbs

If you haven’t gotten bulbs in the ground yet, don’t despair. As long as the soil temperature stays above 40 degrees F roots still have time to develop. This means you should still have success if you plant bulbs into early November. Check soil temperature readings for the previous week at our Weather Data Library: http://mesonet.k-state.edu/agriculture/soiltemp/

Healthy bulbs should be large, firm and dormant. Do not choose bulbs that have sprouted. Bulbs need well-drained soil. Incorporate peat moss, well-rotted manure or compost into the soil to prepare for planting.

Test the soil for fertility and follow recommendations from the results. You may see high phosphorus levels if you test the soil in an area that is fertilized regularly. This can be problematic because phosphorus can hinder the uptake of other essential micronutrients. In these situations, use a fertilizer that is relatively high in nitrogen such as 29-5-4 or 27-3-3. Although these are lawn fertilizers, they are suitable for this purpose as long as they don’t have a weed preventer or killer incorporated. Apply at the rate of 2/3 pounds (3 cups) per 100 square feet.

Blood meal is an organic fertilizer that is low in phosphorus and can be applied at a rate of 2 pounds of 12-0-0 per 100 square feet (1 tsp per square foot). Cottonseed meal (6-0.4-1.5) can be applied at 3 pounds per 100 square feet (2 tsp/square foot) or soybean meal (7-2-1) can be applied at 3 pounds per 100 square feet (2 tsp/square foot).

If a soil test is not available use a balanced fertilizer such as 5-10-5 or 6-10-4 at a rate of 3 pounds (6 cups) per 100 square feet (2 tsp/square foot). Fertilizer supplements need to be thoroughly integrated with the soil prior to planting.

The depth bulbs should be planted is typically two to three times the size of the bulb. This varies depending on the species so check planting instructions for more accurate recommendations. (Cynthia Domenghini)


Perennial Garden Clean-up

As the first frosts of the season strike, perennials are showing signs of fall. Though we often think of fall as a time to clean up the garden and remove debris, leaving some plant material intact is okay. Ornamental grasses and herbaceous perennials can provide seasonal interest even in dormancy. Instead of removing the above-ground growth, allow the dried foliage to bring color and form to the otherwise barren winter landscape. Foliage can also provide some insulation against winter weather for the plant crown. Wildlife can benefit from seed heads left to develop on the plant as well.

Two caveats are herbaceous perennials that had disease and pest issues during the growing season and ornamental grasses growing near structures. Diseased or infested plant material can spread from year to year and dried grasses can present a fire hazard. In these situations, remove the above ground growth during fall clean-up. (Cynthia Domenghini)



Fall Colors of Trees

During the growing season leaves are making food for trees through photosynthesis. Chlorophyll found in the leaves captures the energy of the sun and gives trees their green pigment. As the amount of daylight decreases and the temperature drops heading into fall, chlorophyll production slows and the green color of leaves begins to fade. Xanthophylls and carotenes which are responsible for the orange and yellow pigment are always present in the leaves but only become visible as the green fades. Tannins are also present throughout the growing season and produce brown colors. Anthocyanins create red and purple pigments and are primarily produced during the fall.

The timing and intensity of the fall display varies based on types of trees and the environmental conditions. Different species will have differing levels of these pigments. Certain types of oaks and maples have brilliant fall foliage displays with varied colors while some trees will display primarily one color.

Temperature, soil moisture, rainfall and amount of sunlight impact the intensity and duration of the color. Warm, sunny days encourage photosynthesis which means sugar accumulation in the leaves. Cool nights slow respiration which helps conserve sugars. The combination of these factors results in a brilliant foliage display. Cloudy days and warm nights reduce sugar accumulation and consequently result in less vibrant leaf colors. Heavy rain, hot and dry summers, and frosts/freezes all have a negative effect on the vibrancy of fall colors and length of time they remain.

During this time, an abscission layer develops where the leaf petiole attaches to the branch. This barrier prevents sugars from being transported out of the leaf to the rest of the tree. Once the abscission layer is present, the leaf is ready to drop to the ground with the help of a windy gust or rainy day.

If you’ve noticed the fall display in your landscape changes from year to year pay attention to the weather patterns and this should give you an explanation as to why. (Cynthia Domenghini)



Caring for Houseplants During the Winter Months

Houseplants require the most attention during the. During this time, they are growing more due to the additional energy generated from the increased number of daylight hours. This results in a need for more water and nutrients. As we head deeper into fall and approach winter, daylight hours decrease and plant growth does too. Consequently, the need for added nutrition and water decreases. Too much water can cause the soil to become waterlogged making it so the roots cannot take in oxygen. Pay attention to the plant needs and only water when necessary. Insert your finger about 1-inch deep into the potting soil. If the soil is dry, it is time to water. Excess fertilizer can burn plant roots. It is recommended to only fertilize sparingly in November and February (about ¼ the normal rate), and stop fertilizing altogether in December and January. (Cynthia Domenghini)


Preserving Garden Tools

Tools with wooden handles need protection from wear and tear. Store these tools in an area where they will not be exposed to poor weather conditions. This will help prevent splintering. Wooden handles that are becoming rough can be sanded lightly and coated with a light application of wood preservative, boiled linseed oil or polyurethane. After a few minutes wipe off the excess coating. Clean the dirt off the metal parts to prevent rust. Some quick maintenance will increase the life of your tools and save you money from having to replace them. (Cynthia Domenghini)


Harvesting and Curing Black Walnut

Black walnuts are ready for harvest when the hull is soft enough to be dented by your thumb or when they start falling from the tree. Walnuts must be hulled soon after harvest to avoid a stain leaching through to the meat of the nut. The stain discolors the meat and gives it an undesirable flavor.

Walnuts can be hulled several ways, but the easiest is to mow over them with the lawn tractor breaking the shell but not the nut. Wear gloves when handling black walnuts as the dye they contain is very difficult to remove and will tint anything it touches. Spread the hulled nuts onto the lawn or on a wire mesh and spray with water to wash them. Alternatively, you can soak them in a tub of water. To dry the nuts, spread them out in a cool, shady, dry location for about two weeks. (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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