Christmas is just around the corner. Christmas trees, holly wreaths and mistletoe are just a few of the natural icons of the season. Back in the 18th and 19th centuries, the British started hanging mistletoe as part of Christmas celebrations and this mysterious little plant became synonymous with a kiss. Mistletoe was supposed to bring luck to two people who kissed underneath it and bad luck to those who didn't.

Mistletoe can be found growing in trees all across the southern United States and is easily spotted during the winter. Mistletoe is a small evergreen shrub that is semi-parasitic with tiny yellow flowers that bloom from fall into winter. The plants can reach 3' across and are either male or female. Only the female plants produce the ever familiar white berries. The berries are an excellent source of food for birds in the winter and the mistletoe is dependent upon the birds for dispersing the seeds. The berries are poisonous to humans and should not be eaten, but birds seem to be immune to any toxicity.

Mistletoe plants do not have true roots but use extensions called holdfasts to grip tree limbs and steal water and nutrients from its host. Mistletoe does make some of its own food so it may not kill a tree outright but it will weaken the tree over time. Healthy trees can tolerate a few unwanted guests but a heavily infested tree may be seriously harmed when combined with the stress caused by drought, insects, or disease. The best way to fight an infestation of mistletoe is to keep trees healthy. Watering during periods of drought, using mulch, maintaining the proper pH and proper fertilization will help reduce the amount of stress your trees are under. Cutting Mistletoe flush to the branch will not kill it. Infested branches would need to be pruned out, which may not be practical. When handling mistletoe keep in mind that all parts of the plant are poisonous so wash your hands and keep it out of a child's reach.

As I was writing this article, I enjoyed the sight and sound of some desperately needed rain. This rain reminded me of another tree dwelling plant we have not been able to see for several months. The Resurrection fern (Pleopeltis polypodioides), is a species of coarse-textured fern native to the Americas and Africa. It lives in the hardwood forests of the southeast from Delaware to Florida. The leathery, evergreen fronds of this fern attach themselves to the limbs of trees by a creeping, slender rhizome. This fern is an epiphyte, a plant that grows harmlessly upon another plant and derives its moisture and nutrients from the air and rain. Epiphytes differ from parasites in that epiphytes grow on other plants for physical support and do not harm the host. Many mosses, lichens, ferns, cacti, orchids, and bromeliads are epiphytes.

The Resurrection fern can often be seen carpeting the limbs of large trees here at Lockerly Arboretum. However, it can also live on other surfaces such as rocks and walls made of concrete blocks. The resurrection fern gets its name from its ability to survive long periods of drought. During dry periods, the fronds will curl up and appear desiccated, brown and dead, but with a little rain, the fern will uncurl and "resurrect" itself. Its vivid green color is often restored within 24 hours. The fronds can lose up to 97% of its moisture and remain alive, while most other plants would die after losing only 8-12%.

If you have sustained any loses in your landscape recently due to the extended drought, you are not alone.  Many of the leucothoe, anise, azaleas and conifers here at Lockerly were lost over the past 2 months.  Many more loses may become evident next season since plants can suffer from drought related problems for many years. The effects of drought on trees and shrubs can range from wilting, leaf scorch, and defoliation to stunted growth, branch die-back, and death. Many woody plants can take up to three years after a drought to display negative long-term effects.  

 

During a prolonged drought, the fine feeder roots in the upper soil surface will die. This puts the root system out of balance with the amount of foliage found aboveground. When rain does return, the plant may not be able to utilize the water because of its reduced root system. The result is a resizing of the canopy through branch die-back. If drought persists into the next growing season or recurs before the plant can fully recover, the entire plant may die. Only time will tell how much more damage we will see from our lack of rain during October and November.