Sprigs of holly, mistletoe and poinsettias of many colors are favorites for holiday decorating. ISU Extension horticulturists explain what grows in Iowa, how they grow and a bit of the traditions behind these festive plants.
Can hollies be successfully grown in Iowa?
American holly (Ilex opaca) and English holly (Ilex aquifolium) are prized for their glossy, green leaves and brightly colored fruit. Sprigs of both hollies are often used in wreaths, centerpieces and other Christmas decorations. Unfortunately, American and English hollies are not reliably hardy in Iowa. However, winterberry (Ilex verticillata) and Meserve hybrid hollies (Ilex x meserveae) can be successfully grown in the state.
Hollies are dioecious. Dioecious plant species produce male and female flowers on separate plants. Only female holly plants produce the red, berry-like fruit. However, a male plant is required for pollination and fruit set.
While most hollies are evergreen, winterberry is deciduous (loses all of its leaves in fall). Winterberry grows 6 to 10 feet tall. The fruit on female plants turn bright red in fall and persist into winter. (Birds usually devour the fruit by mid-winter.) Excellent fruiting varieties include ‘Sparkleberry,’ ‘Winter Red,’ ‘Afterglow’ and ‘Red Sprite.’ ‘Jim Dandy’ is a good pollinator for ‘Afterglow’ and ‘Red Sprite.’ ‘Southern Gentleman’ pollinates ‘Winter Red’ and ‘Sparkleberry.’ Winterberry performs best in moist, acidic soils. Plants can be grown in partial shade to full sun. Best fruiting occurs in those areas that receive at least six hours of sun.
Meserve hybrid hollies are evergreens. ‘Blue Prince,’ ‘Blue Princess,’ ‘Blue Boy’ and ‘Blue Girl’ have dark, bluish green foliage and are often referred to as blue hollies. The female varieties have colorful red fruit. Other attractive Meserve hybrids include China Boy® and China Girl®. Meserve hollies are variable in height. Most varieties grow 5 to 10 feet tall. They are hardy to -20 F (USDA Hardiness Zone 5). In Iowa, Meserve hollies perform best in the southern half of the state. Meserve hollies are susceptible to desiccation injury from the sun and dry winds in winter. When selecting a planting site, choose a protected location, such as on the east side of a building.
What is mistletoe?
Mistletoe is a semi-parasitic plant with leathery, evergreen leaves and small, white berries. Mistletoe plants manufacture their own food, but obtain water and mineral nutrients from a host plant. Host plants include numerous deciduous and evergreen trees. Mistletoe obtains water and nutrients via root-like haustoria that grow into the host plant’s water conducting tissue. Mistletoe berries are readily eaten by birds. The birds digest the pulp of the berries and excrete the seeds. The sticky seeds stick to the branches of trees. At germination, the mistletoe seedling develops haustoria that grow through the bark of the tree and into its water conducting tissue.
American mistletoe (Phoradendron leucarpum) can be found growing in deciduous trees from New Jersey and southern Indiana southward to Florida and Texas. (Phoradendron is derived from Greek and literally means “thief of the tree.”) It is the state floral emblem of Oklahoma. Mistletoe sold during the holiday season is gathered in the wild. Most mistletoe is harvested in Oklahoma and Texas.
Traditions involving mistletoe date back to ancient times. Druids believed that mistletoe could bestow health and good luck. Welsh farmers associated mistletoe with fertility. A good mistletoe crop foretold a good crop the following season. Mistletoe was also thought to influence human fertility and was prescribed to individuals who had problems bearing children. It has been used in medicine, as treatment for pleurisy, gout, epilepsy, rabies and poisoning. In addition, mistletoe played a role in a superstition concerning marriage. It was believed that kissing under the mistletoe increased the possibility of marriage in the upcoming year. Today, kissing under the mistletoe is a sign of goodwill, friendship or love.
Mistletoe should be kept out of the reach of small children and family pets, as the berries are poisonous.
Can you give me a brief history of the poinsettia?
The poinsettia (Euphorbia pulcherrima) is native to Mexico. In Mexico, the poinsettia is a large shrub or small tree that may reach a height of 10 to 15 feet.
Poinsettias were cultivated by the Aztecs, who called the plant Cuetlaxochitl. They used the colorful bracts to make a reddish purple dye. The poinsettia’s milky sap was used to treat fevers.
After the Spanish conquest and the introduction of Christianity, poinsettias began to be used in Christian ceremonies. Franciscan priests used the poinsettia in their nativity processions.
Poinsettias were first introduced into the United States by Joel Roberts Poinsett, the United States Minister (ambassador) to Mexico from 1825 to 1829. Poinsett had plants sent to his home in Greenville, S.C. He then distributed plants to botanical gardens and horticultural friends, including John Bartram of Philadelphia.
The popularity of the poinsettia as a holiday plant grew rapidly in the latter half of the 20th century with the development of shorter, free-branching, longer-lived cultivars. Plant breeders also expanded the color range of the poinsettia. Poinsettias are now available in red, pink, white and gold. Variegated and marbled poinsettias also are available. Today, the poinsettia is the number one flowering potted plant in the United States.