Horticulture 2023 Newsletter No. 49

KSRE Horticulture News



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

Video of the Week: Plant Amaryllis Bulbs for Winter Color



Storing Potatoes in Cold Temperatures

Ideally, potatoes should be stored in a cool garage or basement where the relative humidity is 90% and the temperature is between 40- and 45-degrees F. Although they can be stored for long periods of time in temperatures below 40-degrees F, the starches begin converting to sugars which alters the flavor of the potatoes. If this happens in your storage area, keep the potatoes at room temperature for two to three days prior to consuming and the desired flavor should return. If stored above 45-degrees F for prolonged periods of time, the potatoes will begin to sprout. Potatoes will become soft and shriveled if the relative humidity is too low. Storing potatoes in perforated plastic bags will help maintain higher humidity levels. (Cynthia Domenghini)


To select a live Christmas tree that will last the holiday season avoid these red flags.

Dull, gray-green needles
Dry, stiff and brittle needles
Needles drop from tree easily
Some commercial sites sell cut trees that have already been stored for several weeks so evaluate these carefully before purchasing.
When you get your tree home, recut the trunk about one inch above the base just before placing it in the stand. This will open up the plant tissues that enable the tree to pull in water. Place the trunk into the stand with water immediately after cutting.
As with traditional houseplants, avoid placing your Christmas tree near heat sources or drafty windows and doors. It is important to always keep water in the tree stand reservoir. If the cut end of the tree is exposed to air for several hours it will begin to seal over and need to be recut again. Fresh cut trees tend to absorb a lot of water during their first couple of weeks so check the water level at least every other day. Ensure the base of the tree has access to the water in the stand as the level drops.

Living trees are a great option for homeowners who have space to add to their landscape. This requires a bit more planning by selecting a tree that will work in your landscape and climate. It is also a good idea to dig the hole where the tree will be planted prior to when the ground freezes so it can be planted soon after the holidays.

Living trees should only be kept indoors for a few days. Trees kept indoors too long will come out of dormancy and initiate new growth. If the tree is then moved outdoors during winter, it will not be hardy to the cold conditions and can suffer extreme damage or even death. At planting, water the tree in well and apply a layer of mulch to prevent the water from freezing. (Cynthia Domenghini)


Care of Christmas and Thanksgiving Cacti

Christmas cactus (Schlumbergera bridgesii) and Thanksgiving cactus (Schlumbergera truncata) look exotic but are rather easy to maintain with the right growing conditions. While in bloom, water the plants when the soil surface is just becoming dry to the touch. Never let the plants remain in standing water and well-drained soil is a must.

Holiday cacti bloom in response to the shorter days and cooler nights we experience heading into winter. If you are gifted a Christmas cactus this season, to prolong the bloom, keep the daytime temperature between 60-65 degrees F and the nighttime temperature between 55-65 degrees F. Keep your cactus in total darkness for at least 12 of every 24 hours. The plant should receive bright, indirect light for the rest of the time. Sudden changes in temperature can cause the cactus to drop its blooms. When transporting it home be mindful of the outdoor temperature and take measures to protect your plant from the cold.

The segments of the holiday cactus that look like leaves are actually stems known as “phylloclades”. When your cactus finishes blooming, you can prune it at the union of two of these segments. Each cut phylloclade remaining on the parent plant will produce one to two new stem segments. This will encourage branching and a fuller plant. The cuttings removed from the plant can be propagated into new plants. Dip the cut-end of the stem into water and then rooting hormone, which can be purchased at garden centers or online. Secure this end into potting mix and keep it moist and in a warm location with bright light. Once roots develop you can transplant it into a cactus/succulent media.

While the parent plant is not blooming, decrease the water and care for it as you would a typical houseplant. When the danger of frost has passed, holiday cacti can be moved outdoors in part shade. Beneath a tree is a great location that will provide filtered light. If the stems begin to turn pale they may be receiving too much light. Fertilize once each month in June, July and August at half-strength with a balanced houseplant fertilizer. As the temperature drops to the low 50s at night bring your cactus back indoors. When flower buds begin to develop switch to a fertilizer low in nitrogen and higher in phosphorus and potassium. (Cynthia Domenghini)


Heat Value of Firewood

Certain tree varieties produce firewood that gives off more heat than others. Osage orange, honeylocust, black locust, bur and post oaks all have high heat values. However, osage orange firewood tends to spark which can be dangerous, especially in an open fire. If you’re harvesting your own firewood, it is beneficial to note wood from certain species, such as black locust and elms, is difficult to split.

The Kansas Forest Service has published a great resource for landowners about this topic: “Managing your Woodland for Firewood”.

Homeowners who plan to purchase firewood should buy local to avoid spreading pests including Emerald Ash Borer. The chart below ranks the woodland species in terms of the heat value (measured in British Thermal Units, BTUs) per cord of wood. A cord is the amount of wood, stacked well, in a pile that measures 4 feet wide by 8 feet long by 4 feet high. Higher BTU values indicate more heat produced. (Cynthia Domenghini)

Tree Variety


Ash, Green




Elm, American


Difficult to split

Elm, Red


Difficult to split

Elm, Siberian


Difficult to split






Locust, Black


Difficult to split

Maple, Sugar


Maple, Silver




Oak, Red


Oak, Bur


Oak, Post


Osage Orange


Tends to spark



Difficult to split

Walnut, Black



Cynthia Domenghini, Instructor and 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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