By:  Eddie Ayers, County Extension Agent

Leyland cypress is a popular, fast growing hedge or border tree reaching heights of 50 to 100 feet and widths of 20 to 30 feet. Though Leyland cypress originally appeared pest resistant, problems have recently become apparent. Over use of this plant, improper site selection, improper planting, and stressful weather conditions have led to two disease problems.  They are cankers and root rot.

Cankers are infected wounds on limbs and branches that may ooze infectious sap.  The trees get the canker because of fungi entering the tree. Leyland cypress can actually get two canker diseases.  Botryosphaeria Canker is one type and it is commonly called Bot Canker which kills individual branches in the tree. The foliage may turn rust colored before it dies.  The dead branch will have darker bark and will have a sunken canker where the dead part of the branch begins. The other canker is Seiridium Canker. Limbs infected with Seiridium Canker turn yellowish and then brown when they die.  Limbs often die back from the tips. The cankers on the main stem are sunken, reddish and ooze sap profusely. There can be many cankers on a limb and unfortunately, there is no spray to control these diseases.  The diseases enter wounds and are worse during stressful conditions. The main control is to keep the plant in good health so it can resist these diseases. Extreme weather and improper watering can be big factors in the spread of these diseases.  Plants with roots that get too wet or too dry are more likely to get either these canker diseases or root rot.

Even though we have been getting plenty of rain lately, the tree has suffered through years of drought, poor sunlight, and above average rain.  Over a period of years this adds stress to the tree. If the weather turns into a drought, water plants deeply once every 7 – 14 days and wet the soil to a depth of twelve to eighteen inches when watering.  Soil must dry out between watering or roots may die. Avoid wetting the leaves and limbs when you water. Soaker hoses are better because they keep the foliage dry, which may reduce disease problems.

Selecting the proper planting site will go a long way in helping prevent disease problems.  Leyland cypress planted too close together, near paved areas, next to walls or other heat reflecting surfaces may need special care in watering and planting to get established and to grow well.  Plant Leyland cypress in well-drained soil in sunny locations. Mulch them after planting but mulches should be no deeper than two to four inches. Apply mulch from the base of the tree out to several feet beyond the reach of the branches.  Because it holds in water, do not use landscape fabric unless the soil is very well drained. Do not pile mulch against the base of the plant.

Do not plant Leyland cypress in wet soils or poorly drained areas.  They may respond to wet feet by developing root rot or dying. Check soil drainage before you plant or if the tree has problems.  Dig a hole about a foot deep and wide. Fill it with water. If it takes longer than three hours for the water to drain out, the soil is probably poorly drained.  Do not plant Leyland cypress closer than eight feet. As the plants get big enough for the limbs to touch, remove every other tree. As the limbs rub together, they cause wounds that can be infected by the fungi which causes the canker diseases.

If your Leyland cypress already has these diseases, first cut out the dead limbs.  Be very careful to make cuts into good live disease free tissue. Cutting diseased limbs and then good limbs may spread the disease.  While pruning you can periodically clean your shears with a towel dipped in rubbing alcohol. Leyland cypress generally does not respond well to cuts on the main stem, but if you have cankers on the main stem, remove the tree or cut below the canker and see if the tree recovers. Nothing can be done about the weather, but you can lower the stress on the tree.  If you experience a lot of problems you’re your Leyland cypress, you might want to consider using a different plant.

For more information view the publication entitled Diseases of Leyland Cypress in the Landscape on our web site at http://extension.uga.edu/county-offices/gilmer.html or contact me in the Gilmer County UGA Extension office.

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By:  Eddie Ayers, County Extension Agent

Are some of your plants suddenly dying?  Did the tulips forget to bloom this spring?  After you hunted for some bulbs, did you find little tunnels in and around your flower beds?  If so, you may be a victim of the pine vole.

Often confused with moles, pine voles can be found in underground tunnels.  In fact, they may use mole runs just to make it easier to move around. Pine voles are usually 4 to 6 inches in length and are covered with brown, dense fur with a bicolored tail.  Their under parts are gray.

Pine voles prefer areas with a heavy ground cover of grasses.  They like living in deciduous and pine forested areas, abandoned fields and orchards.  They will eat grasses, seeds, tubers, bulbs and any underground growing part.

There are 23 vole species across the country.  They can cause extensive damage to orchards, ornamentals and trees due to their girdling of seedlings and trees.  Girdling usually occurs in fall and winter. The easily identifiable sign of voles is numerous burrow openings of about an inch around shrubs and flowers.  Voles are active day and night, year round, and they do not hibernate during the winter. Their “home” range is usually ¼ acre or less.

Moles, on the other hand, are found throughout a lawn or garden.  They have runs and push up soil just like the voles, but they do not come out of the ground.  They stick to a diet of grubs and other crawly creatures found in the soil, and they will sometimes kill plants as their tunnels will create air pockets that roots cannot live in, so proper identification of the mammal is important.

After identifying the culprit, controlling these rodents can be challenging.  Keeping grass in an area short helps with control because they do not like to move across open areas because of flying enemies.  Frightening devices or repellents generally do not work and although owls, snakes and hawks are predators of voles, they seldom control vole populations.  However, trapping, using a mouse snap trap, is effective along an active run during the winter. Favorite baits are peanut butter-oatmeal mixtures or apple slices.  Place several traps around a hole and cover it with a box to fool them with shelter and prevent pets from getting in the traps and if by chance one gets into a home, setting a snap or live trap as you would for house mice results in successful control.

If you are seeing the pushed up soil runs made by moles, there are two basic types of control.  There are harpoon traps that can be placed over an active run, but these are very tricky to use.  The most effective control has been to apply granular insecticides labeled to kill grubs. These will limit the moles food source and they will leave the area if they don’t have anything to eat.  The down side to this method is that the granules will also kill the beneficial critters that live in the ground. Remember when using any insecticide to always read and follow the label directions.

For more information, contact me in the Gilmer County UGA Extension office.