By Sarah Preiss-Farzanegan, M.D.
UCCE / El Dorado County Master Gardener
Food and family aside, a few of the most recognizable and popular Christmas traditions are plants.
Holly and ivy plants, besides being a popular caroling tune, were the traditional evergreen bough brought indoors to celebrate the holiday before the Christmas tree was popularized in the early 1800s. Ivy needs little encouragement to grow upwards on anything it can find. Holly blooms in the middle of winter with bright green leaves and brilliant red berries (that can cause stomachache, vomiting and diarrhea when eaten).
Another familiar plant is mistletoe, which in its natural habitat is a parasite that grows on apple, poplar and oak trees. Hanging mistletoe was originally done to ward off evil spirits and encourage spring blossoms, then the Victorians hung it in doorways and from ceilings during holiday festivities and socially-acceptable kisses were exchanged beneath it. A berry was removed for every kiss — and when all the berries were gone, the kissing stopped.
Amaryllis and the Christmas cactus are flowering plants commonly seen this time of year that, unlike holly, do not naturally bloom in December. The amaryllis plant, Amaryllis belladonna, is native to South Africa; what is commonly sold around the holidays as “amaryllis” is usually from the genus Hippeastrum or is a hybrid of several species from South America and South Africa. The bulbs grow well in containers and are easily forced to bloom around the holidays. First, place a half-inch of gravel in the bottom of a small pot, then put the bulb in the pot leaving room for 1 inch of soil between the bulb and the rim of the pot. Add the soil and leave one-half to two-thirds of the bulb neck above the soil surface. Water thoroughly after potting and keep the soil moist until it flowers — then increase the watering frequency to prolong flowering. In the spring, container-grown bulbs can be transplanted outside.
The Christmas cactus, also known as the orchid cactus, is a long-lived plant that is easy to grow. It belongs to the zygo-cactus family, which is native to Central and South America. This particular cactus is an epiphyte, a plant that derives moisture and nutrients from the air and rain and usually grows on another plant but is not parasitic. The Christmas cactus naturally grows in the forks of tree limbs in decaying leaves and other collected material; it likes small spaces, so it flowers best when kept pot-bound. To encourage your cactus to bloom around Christmas, fertilize it in late October or early November with a 0:10:10 type fertilizer (nitrogen: phosphorus: potassium). Beginning in September or October, it requires indoor indirect bright light during the day and total darkness at night, cool temperatures (about 50 degrees Fahrenheit, versus the poinsettia which prefers warm temperatures), 50-60 percent humidity and limited watering. The plant does not like to be around fireplaces, drafty areas or doors leading outside. The best way to provide humidity is to keep a vase or glass of water nearby or create a humidity tray by filling a waterproof dish with gravel and then halfway with water. If after blooming the flowers start to fall off, look for over-watering, lack of humidity or not enough light. After the holiday season, let the cactus rest for about a month, keeping it in a cool room with limited water. It may lose a few leaves or appear weak during this time, but not to worry; if well-cared for, your Christmas cactus should flower several times throughout the year.
The poinsettia is another colorful and recognizable herald of the holiday season. It is native to Mexico, but grows well outdoors in certain areas of California and indoors just about anywhere. Its coarse leaves grow on stiff upright canes and are the showy part of the plant. The true flowers in the center are yellowish and rather inconspicuous. Poinsettias bloom when they experience long nights, typically in the winter through spring. In order to coerce your potted plant to bloom for Christmas, move it to a completely dark closet in early October for 14 hours a night and then in a sunny window for a maximum of 10 hours during the day for 10 weeks. Keep your indoor plant in a sunny window, avoid sudden temperature changes and keep the soil moist. When the leaves drop off later in the winter, cut stems back to two buds and reduce watering to a minimum. Store in a cool place until after danger of frost, then set it out in your garden or sunny spot. Note that although the poinsettia’s milky sap is not poisonous, if consumed it can be mildly irritating to the stomach.
Last but not least, the star of the Christmas holiday is a freshly cut Christmas tree. Over half of a tree’s weight is water when you cut it down, so the key to keeping your tree beautiful is proper watering. When you get it home, make a fresh perpendicular cut to remove about a half inch off the end of the trunk. A diagonal cut will not increase water uptake by the tree and will make it difficult for the tree to remain straight in the stand. The temperature of the water is not important in terms of water uptake by the tree and drilling a hole in the bottom of the trunk will not improve water uptake. As soon as possible, put the tree in water. Most trees can last six to eight hours without water after cutting and still be able to take up water. The tree stand should provide 1 quart of water per inch of stem diameter and the water level should be kept above the base of the tree. The biggest problem with fresh Christmas trees is drying out, so monitor the water supply in the stand and minimize other factors that can accelerate the drying process such as proximity to heat sources, decorative tree lights that produce high heat and elevated room temperatures. These will hasten drying process, which will increase the tree’s overall water consumption. And as with any type of tree, inspect light sets before use, take care not to overload circuits and turn off the lights when you leave the house.
All good things must come to an end. In January, lonely, bare trees are strewn across curbs everywhere. Do not burn the tree in a wood stove or fireplace; please consider recycling your Christmas tree. El Dorado County residents may drop off their trees at Waste Connections (MRF) at 4100 Throwita Way in Diamond Springs (530-626-4141 or ehso.com for more information). Happy holidays.
Tomorrow, Saturday, Dec. 4, UCCE Master Gardeners will present a free class on “Selecting and Planting Fruit Trees.” The class starts at 9 a.m. and will be held in the Veterans Memorial Building at 130 Placerville Dr. in Placerville.
It’s never too early to start planning your garden for next spring. Mark your calendars for the UCCE Master Gardener Spring Plant Sale. There will something for everyone: annual, perennials, ornamental trees and shrubs, as well as, a large assortment of vegetables. The sale will be held Saturday, April 16, 2011 at the Veterans Memorial Building at 130 Placerville Dr. in Placerville. All proceeds benefit the Master Gardener outreach programs.
Master Gardeners are available to answer home gardening questions Tuesday through Friday, 9 a.m. to noon, by calling 530-621-5512. Walk-ins are welcome. The office is located at 311 Fair Lane in Placerville. For more information about our public education classes and activities, go to our Master Gardener Website at ceeldorado.ucdavis.edu/Master_Gardener/.