Mistletoe: Tree Thief, Holiday Tradition

Mistletoe: Tree Thief, Holiday Tradition
John Hartman, Plant Pathology Professor Universtiy of Kentucky

Once autumn leaves have fallen, mistletoe becomes highly visible on large trees throughout Kentucky. Phoradendron, the scientific name for this parasitic plant, means tree thief. You can commonly find these small leafy plants on twigs and branches of many hardwood species in the southern two-thirds of the United States. Mistletoes extract water, mineral elements and food from their host tree by way of a parasite nutrient-uptake organ; hence the name, tree thief.

Mistletoes’ use in holiday traditions has roots in pagan times. Its parasitic nature and the fact that it appears to be alive while the host tree appears dead, led some to believe mistletoe mysteriously held the life of the tree during winter. Druids harvested mistletoe in a special rite, never letting the plant touch the ground, then hung it in their homes for good luck.

Our modern-day mistletoe holiday tradition likely originates with a mythological Norse goddess of love and beauty. Frigga, whose son was restored from possible death by mistletoe, was thought to bestow a kiss on anyone walking beneath one. Today, when two people meet under the mistletoe, tradition suggests they must exchange a kiss for good luck.

Phoradendron, the most common mistletoe growing in Kentucky, resembles another species that grows in Europe. It has simple, fleshy green leaves arranged oppositely on the stem. Stems are short and more branched than the host tree, so mistletoe often appears as a spherical bunch of dense vegetation. These bunches may be a foot or two in diameter and are located high in the tree for better sunlight exposure. Mistletoe berries range from white to straw-colored to light red. Birds eat the fruits, reportedly toxic to human and animals, then deposit the seeds onto branches where they germinate and penetrate the host tree.

Since birds tend to roost in open-grown trees, mistletoes do not appear as frequently in forest trees. Generally, they do not cause much damage, although they can be harmful to a tree already under stress. If mistletoe appears on landscape trees or other trees in the urban forest, you can control it through pruning.

Fresh Christmas Tree care

It's that time of year again when christmas decorations begin going up and the decision of when to put up the real tree has to be made.  Always choose the freshest tree possible from a lot you trust.  The needles should bend and not snap.  Also when the tree is thumped against the ground green needles should not dislodge.  Once you have gotten the tree home remove another 1 to 2 inches of the base of the trunk and place the tree in a bucket of warm water.  For a longer lasting tree place the tree out of the direct flow of air and away from direct sunlight.  Once inside and in the stand fill the resevoir with a solution of 1cup of corn syrup and 3 tablespoons of liquid bleach in one gallon of water. Keep the resevoir full with this solution as long as the tree is in the house.

For more specific information go to Christmas tree care.
And for a list of Christmas tree growers in Kentucky visit http://www.kychristmastrees.com/

Blooming Early or Blooming Late

You may have noticed, like many folks, that spring flowering plants haven't given up yet.  Plants like forsythia, lilacs and even iris are blooming this fall.  We can normally blame premature flowering on low rain fall summers followed by wet falls. However that is not the case in this year.  My theory was confirmed after talking to Dr. Rick Durham (our ornament plant specialist at UK) that this premature or late blooming is a result of a wetter and cooler October followed by a warmer and dryer November.  October set the stage for a light dormancy period which was easily broken by our beautiful November weather.  The take home message is we can't really do anything about the situation.  We should hope to see temperatures moderate back to seasonal without any sudden moves down in temperature.

Blossom end rot of Tomato

There has been a lot of calls in the last couple of weeks regarding Tomato fruit rotting prior to harvest. This is called Blossom end rot and occurs every year to varying degrees. This problem is associated with the fluctuation of wet and dry conditions in the soil. Sprays after the fact are not affective for this disorder and actually sprays are not effective prior to this problem. The key to this situation is to maintain soil moisture and not allowing the plants to dry out.

The following link is an article written by Dr. William Nesmith and Dr. Paul Vincelli. http://www.ca.uky.edu/agcollege/plantpathology/ext_files/PPFShtml/PPFS-VG-2.pdf

Take a look I think your questions will be answered.

Bagworms on the Move

I have been receiving calls this week about Bagworms devouring evergreens. First, we need to describe what it is we are looking for and its damage. Unfortunately the damage at this time is more noticeable than the insect. The appears as defoliation at the top of the tree leaving nothing bu the stem. The insect is a caterpillar that lives its entire life inside a bag. The bag is fashioned out of whatever is on the tree. It could be pieces of leaf, berries, or twigs and the results are a very camouflaged appearance. They start out very tiny and result in a capsule over an inch in length. For much more information and control recommendations please use the link below. http://www.ca.uky.edu/entomology/entfacts/ef440.asp

Orange Rust on Blackberries

Last week I found the first outbreak of Orange Rust in Nelson County this year. Orange Rust is a big threat to the commercial Blackberry industry in Kentucky. Nelson county has about ten acres of Blackberries planted and that is expanding yearly.

The main problem associated with Orange Rust is the fact that once the plant becomes infected with the disease it can't be healed. Orange Rust moves systemically within the plant infecting the roots, crown, stem, and foliage. The plant will become less vigorous and decline with time. It is easily recognizable this time of year due to its large orange pustules that populate the underside of the leaves. For more information on how to control Orange Rust on Blackberries visit: http://www.ca.uky.edu/agc/pubs/ho/ho15/ho15.pdf

Freeze Damage to Ornamentals

It has been eleven days since the Easter freeze and we are still in a wait and see pattern. Many plants were very successful, an example would be the Hawthornes on Stephen Foster that are in full bloom today. I received word this morning that apples may end up with a crop after all. Flowers were open yesterday and Bees were in a flurry of activity.

For most ornamental plants we need to wait and see what happens before we take action. Do not fertilize this spring that will only make the problem worse however fertilization will be important this fall. There will be some plants like Japanese Maples that will likely have stem dieback which will require heavy pruning and as I said before other plants weren't affected in the least.

For much more information on this subject see the following link: http://www.ca.uky.edu/HLA/Dunwell/KYPlantDamage2007.html