MASTER GARDENERS December 2020 Issue In this issue 2021 Plans State Wide MG Survey ...................................................... 1 • February 6, 2021, 9:00 AM Central – Pikeville (in SVMG Survey .................................................................... 1 person) and possibly a ZOOM option - details to Hours................................................................................. 1 come 2021 Plans ......................................................................... 1 • April 17, 2021, 9:00 AM Central, Dunlap – plans are UT Gardens Plant of the Month ....................................... 2 to meet at the Dunlap Coke Ovens January Gardening Calendar ............................................. 4 • May 1-2, 2021 – Valley Fest • July 24, 2021 – Tomato Tasting, Pikeville, Bledsoe State Wide MG Survey Count Extension office • August 2021 County Fairs Please Fill Out This Brief Survey to Share with Us • November 6, 2021, 9:00 AM Central, Dunlap location YOUR Thoughts on TEMG Programming in 2020! (Click to be announced here to go straight to the UT survey) Mark Your Calendars for our 2021 Regional TEMG Conferences SVMG Survey • May 20, 2021, Eastern Region in Fentress County There is also a survey for SVMG Members • June 24, 2021, Central Region in Warren County https://forms.gle/my6DmmtVs2ENubHE9 • Sept. 17-18, 2021 Western Region in Montgomery County Hours As we near the end of the year and reporting time Short Note please report your hours in the database. The paperwhite narcissus is a popular bulb for • 249.25 Volunteer hours reported thus far (11-1- indoor forcing in the winter months. A common problem 2020) with paperwhites, however, is that they often grow too • 69.5 CEUs reported tall and flop over. Check out the article “Pickling your • Total Hours Value: $5523.38 Paperwhites: Ginning Up Paperwhites That Don’t Flop Don’t worry if the hours do not add up to 25 Over” at volunteer hours or 8 hours CEUs record your effort and http://www.hort.cornell.edu/miller/bulb/Pickling_your_ we will work through any shortfalls. The key this year is Paperwhites.pdf to be making an effort. Please, take a few minutes to update your hours. December 2020 UT Gardens Plant of the Month Christmas Cactus Submitted by Mary Lewnes Albrecht, professor emerita, Department of Plant Sciences The popular Christmas cactus is native to South American tropical rain forests and is quite different from desert cacti. Christmas cacti (and related Thanksgiving and Easter cacti) grow in rock crevices and on tree trunks and branches. Leaf litter and other organic matter accumulate in these spaces providing the growing media. This environment also has filtered sunlight and high humidity. All these cacti are related and named for Belgian horticulturist, Frederick Schlumberger. Thanksgiving cactus (Schlumbergera truncata), Christmas cactus (Schlumbergera bridgesii, synonym Schlumbergera x buckleyi), and Easter cactus (Schlumbergera gaertneri, synonym Rhipsalidopsis gaertneri) and hybrids of these species are collectively called Holiday Cactus. Flower colors include red, pink, purple, orange, and cream. The stems are segmented, Christmas cactus is a cheery addition to indoor holiday flattened to round in cross-section, and feature weak or no spines. decorations. Photo by M. Albrecht, courtesy UTIA. The stems gracefully arch making them excellent for hanging baskets. An easy way to distinguish among the three species is the shape of the segments or cladophylls (translated to “flattened stems”). Thanksgiving cactus has the sharpest teeth or claws along the edges with the Easter cactus having rounded edges. The Christmas cactus segments have smaller teeth but are not nearly so rounded. There are no true leaves on these plants. The pollen-bearing anthers on the Thanksgiving cactus are yellow, whereas the anthers on the Christmas cactus are purplish-brown. Christmas cactus thrives in a well-drained mix rich in organic material. Don’t use the sand-based mixes intended for desert cacti. Use a combination of a peat- based houseplant mix blended in equal parts with a bark-based orchid mix. Pine bark fines or pine bark soil conditioner may also be used instead of the orchid mix. This will provide good water retention and great drainage at the same time. Make sure the pot has drainage hole(s), then water thoroughly allowing excess water to drain thoroughly, before returning the pot to its saucer or outer decorative container. During the active growing season of spring through summer, keep the mix evenly moist. To set flower buds in the fall, allow it to go quite dry between watering. When new growth starts from the branch tips in late winter or early spring, fertilize through summer following the directions for rate and frequency given on the fertilizer package. Overfertilization can damage your Christmas cactus’ fine, scant root system. Give your Christmas cactus bright but indirect or filtered light during summer. Keeping it on the north side of the house under the shade of trees works, as does a screened-in porch. Too much direct light can damage the plant. To encourage flower bud formation in late summer, slowly decrease the amount of water, letting the mix dry out between watering. Flower formation A large specimen of Christmas cactus can make a spectacular display, given the occurs under the shortening days and the cooler nights of autumn. If you keep correct conditions, including lighting. the Christmas cactus outdoors, it can handle night temperatures down into the Photo by M. Albrecht of her own 40s. Don’t let it stay outdoors if night temperatures begin to dip below 40 specimen, courtesy UTIA. degrees F. If it remains indoors year-round, find a space where gets cool (between 55 and 65 degrees F) and where it can be in total darkness for 2 December 2020 approximately 13 hours every night. The cooler the nights, the less dependence on the strict 13 hours of darkness. If the night temperatures are above 70 degrees F, 15 hours of darkness is recommended. Flowers drop off Christmas cactus for many reasons: excessive flower set (too many buds), sudden changes in temperature (drafts from heating vents), amount of light, or moisture level in the growing mix (too dry or too wet). To reduce the chances of bud drop, make sure you water properly, especially during blooming. The numerous petals increase the surface area from which water will evaporate. If possible, do not move your Christmas cactus to another location when buds are present or flowers are open. Don’t worry if the plant gets “too big for its pot.” They can remain in the same pot for several years and grow well when pot bound. And, when it is time to move into a larger pot, prune back the plant and repot into a slightly larger container (for example, go from a 6-inch to an 8-inch pot). The major disease is root rot, which can be prevented by avoiding excessive watering. Potential insect problems include mealybugs, soft brown scale, red spider mites and aphids; however, these are uncommon. America's favorite holiday plant Poinsettias are the number one selling potted flowering plant in the U.S., with sales topping $250 million annually Poinsettias are the favored Christmas holiday potted plant. While red is still the traditional color, pinks, whites, variegated, salmon, yellow and even orange varieties abound, says Susan Hamilton, director of the University of Tennessee Gardens. Plant sizes vary from standard 4- to 6-inch pots, to miniatures to tree forms and even hanging baskets. “It’s amazing what greenhouses and garden centers are offering this season with free, professional advice on how to get the most from this holiday plant,” says Hamilton. Some of the new and unique selections you may see include: ‘Orange Spice,’ a true orange poinsettia great for any Tennessee Volunteer fan; ‘Ice Punch,’ a cranberry red with a frosty white pattern; ‘Peppermint Twist Winter Rose’ and ‘Red Winter Rose,’ which have globe-shaped bracts as you’ve never seen on a poinsettia; and ‘Red Glitter,’ This Photo by Unknown Author is licensed under red with a lot of white splotches that give a striking look. CC BY-SA “Not-so-new selections on the market — but ones you are likely to find readily available, and I would never hesitate to purchase — are the ‘Freedom’ series of red, pink, white, jingle bell and marble, which have vibrant colors and long-keeping quality. A novel twist on the common poinsettia is to interplant ferns, creating what is called the ‘Fernsettia.’ If you’d like to add some pizzazz, most garden centers can spray paint or put glitter on a poinsettia!” exclaims the gardening expert. Regardless of the size or variety, poinsettias like bright light and even moisture. They cannot tolerate going too dry. If a poinsettia wilts, it will proceed to lose most of its leaves. With plenty of light and even moisture, they can keep their colored bracts for many months. Flowers or Foliage? The poinsettia (Euphorbia pulcherima) does not have showy flowers. Rather, the bracts, or modified leaves, create the splash of color during the holiday season, while the true flowers are small and insignificant. The colorful foliage of poinsettias is a response to photoperiod, the hours of daily sunlight. There are so many shapes, sizes, and colors of poinsettias available that there is one to fit any indoor setting. Are Poinsettias Poisonous? Contrary to popular belief, Hamilton assures consumers that poinsettias are not poisonous. However, several plants in the same family as poinsettia are poisonous. “The Ohio State University conducted research on the poinsettia plant, effectively disproving the charge that the poinsettia is harmful to human and animal health. Of course, the poinsettia, like all ornamental plants, is not intended for human and animal consumption,” she said. A Bit of History According to Hamilton, the first known use of poinsettias for holiday celebrations occurred in the 17th century when a group of Franciscan priests settled in southern Mexico.