Crossville Chronicle, Crossville, TN

June 17, 2013

PLATEAU GARDENINGS: Beware of ticks, mosquitoes and chiggers, part 1

By C. Rae Hozer
Chronicle contributor

CROSSVILLE — "Plateau Gardening" reader Mike sent an inquiry asking when to transplant shrubs and trees. The gist of his message:

“I would like to move a rather large rhododendron (about 9’ high with a 5’ spread) and want to do it during the most beneficial timeframe for the plant. Also have an opportunity to relocate a couple of saucer magnolias. Would like to know the proper time to transplant them as well as the optimum light to put them in (full sun, partial shade, what?).”

The short, direct answer is that mid- to late autumn after leaves have dropped from deciduous trees and shrubs (indicating landscape plants have entered dormancy) up through January is the most beneficial period for transplanting the majority of woody-stemmed species in climatic regions with the relatively mild winters typical in Tennessee. Late spring/early summer is not a good time.

Before detailing reasons to plant or relocate woody plants later in the year, I want to first warn readers of a current danger from mosquito, tick and chigger bites. People, their pets and livestock are potential targets. Gardeners may encounter these pests in stands of weeds, tall grass, wildflowers or garden plants. Hikers, golfers and others active out in open air could encounter them while working or playing. They may be in yards or parks, on vegetation growing along hiking/walking trails or at the edge of woods, streams and pathways on golf courses.

During May and June, daytime air temperatures have been warm, the mercury at night above frost levels and rainfall plentiful. Water pools after rain storms. Mosquitoes use stagnant water to develop. The egg-to-adult mosquito life cycle can be completed in less than a week when temperatures are right (read the University of Tennessee Extension publication "Sp503-B Mosquito Control Around Homes"). Adult female mosquitoes hide in plants waiting to get a blood meal from passing animals.

Warmth and moisture encourage plant growth. In tall, thick, lush vegetation, the environment is humid even during hot, sunny daylight hours. That humidity helps keep insect numbers high. Expect a drop in insect populations there once spring rains give way to summertime periods of drought. While it is wet, chiggers are usually found in tall vegetation. During dry periods, expect to find chiggers in shady areas.

Mosquito, tick and chigger bites are itchy and annoying, at best. At worst, ticks and mosquitoes in Tennessee are potential carriers (vectors) for diseases they can pass to humans with a bite. In this state during 2012, a particularly high number of people were infected by the mosquito borne illnesses West Nile Virus and La Crosse Encephalitis and by tick borne problems like Rocky Mountain Spotted Fever, Human Monocytic Ehrlichiosis and Lime Disease. There were some deaths. Since temperatures hit summer-like highs early in 2012 but those highs stayed away until late April this year, the number of such cases in 2013 should be lower.

Take precautions to avoid becoming a Centers for Disease Control statistic. Suggestions for avoiding bites and the possibility of contracting a subsequent mosquito borne or tick borne illness include:

1. First, stay away from mosquito, tick and chigger habitat by avoiding wooded or brushy areas, high vegetation and/or leaf litter.

2. Peak mosquito biting hours are from dusk through the night to dawn. Avoid outdoor activities during that time. 

3. When you are outside, use repellent and protective clothing with long sleeves and long pants with socks. 

4. Wear light colored clothing. Crawling ticks show up better on a light background. Female mosquitoes (they bite, the males don’t) are attracted to dark colors, warm body heat and carbon dioxide.

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Plateau Gardening is written by Master Gardeners for gardeners in Tennessee’s Upper Cumberland Region.  Contact UT Extension Cumberland County at P.O. Box 483, Crossville, TN 38557 (484-6743) for answers to horticulture questions, free publications and how to become a Master Gardener. Send email comments or yard and garden inquiries to Master Gardener Rae,