INDEX
Sage Advice for the Midwest
The (Plant) Doctor Is In
Kelaidis Wins Scott Award
Bad News for Fruit Growers

Sage Advice for the Midwest

There are more than 900 species and countless cultivars in the genus Salvia, so selecting the best sage for your garden can be a challenge. The Chicago Botanic Garden's Plant Evaluation Program is making the choice a bit easier for midwestern gardeners. After five years of testing-from 1993 to 1998-the garden's staff has just released the results of their evaluations comparing ornamental characteristics of 15 perennial sages that are considered potentially hardy to at least USDA Zone 5.

Among the criteria considered for comparison were flower color and size, bloom period, foliage quality, habit, and reseeding potential. Half the plants of each selection tested were cut back after first bloom to determine reblooming potential and late-season ornamental value. Also evaluated were winter hardiness, cultural adaptability, and insect and disease resistance.

The top-performer was Salvia 5sylvestris 'Mainacht' ('May Night'), which received high ratings in all categories. Its deep violet flowers occur profusely on plants that are 27 to 30 inches tall, with a slightly greater spread. While cutting back plants following their initial bloom period did not significantly influence rebloom, it did improve the overall appearance of plants late in the season. Another cultivar of the same species, 'Wesuwe', also performed well. It is similar in appearance to 'Mainacht', but its flowers open a week later and are slightly lighter in color. 

Exceptionally high ratings were also given to Salvia verticillata 'Purple Rain'.  Its purple flowers are set off by violet bracts, which remain attractive after the flowers have faded. This selection displayed the highest degree of rebloom of all those tested, and cutting back was not necessary to encourage a second flush of flowers or to retain an attractive habit.

All the sages tested proved to be hardy, easy to grow, and resistant to insects and diseases. To receive a copy of the hardy sage evaluation (Issue 14), send $2 with your request to: Plant Evaluation Notes, Chicago Botanic Garden, 1000 Lake Cook Road, Glencoe, IL 60022. Checks should be made payable to the Chicago Botanic Garden.

The (Plant) Doctor Is In

If your dogwood is looking a little droopy or strange bugs are munching your prized hibiscus, fear not. Thanks to a unique new degree program at the University of Florida's College of Agriculture in Gainesville, professional plant doctors may soon be on call in your town, willing and able to diagnose and dispense prescriptive cures for ailing flora. 

Applications are now being accepted for admission into the world's first and only Doctor of Plant Medicine (DPM) degree program, a three-year, multidisciplinary graduate program designed to train plant practitioners in a manner parallel to medical doctors and veterinarians. In addition to interdepartmental coursework in sciences, business, and communications, students will spend internship rotations with plant pathologists, entomologists, horticulturists, weed scientists, and plant protection specialists, and professionals from other related disciplines. Prior to completion of the program, students will be expected to pass a comprehensive examination, followed by a post-graduate exam before a state licensing board. 

Doctors of Plant Medicine may indeed find employment as private "plant doctors," as well as careers in plant protection, integrated pest management, regulatory inspection, and agribusiness sales. "Graduates are not expected to become researchers," says George Agrios, DPM program director. "Rather, they will be trained to diagnose and offer recommendations for control of anything from disease, insects, weeds, or abiotic causes that adversely affect plant health." The first classes will begin in August 2000. For application materials or more information, call (352) 392-3631, or visit the Web site at http://plantpath.ifas.ufl.edu.

Kelaidis Wins Scott Award

The Scott Arboretum of Swarthmore College in Pennsylvania has honored Panayoti

Kelaidis, curator of plant collections at Denver Botanic Gardens in Colorado, with the 2000 Arthur Hoyt Scott Garden and Horticultural Medal and Award. The Scott award, established in 1929, is given annually to individuals who have made outstanding national contributions to the science and art of gardening.

During his two decades at Denver Botanic Garden, Kelaidis has been instrumental in developing its Rock Alpine Garden, one of the best collections of alpine plants in North America. He has also helped develop and now oversees Plant Select, a plant introduction program tailored to the Rocky Mountains region. Some of the plants introduced through the Plant Select program are the products of Kelaidis's plant exploration trips to South Africa (see page 20 for more details).

An accomplished writer and speaker, Kelaidis has helped stimulate an interest in native and exotic plants suitable for harsh climates such as the Rocky Mountains. He has published more than 100 horticultural articles in a variety of gardening publications and is the recipient of several other awards from organizations such as the North American Rock Gardening Society. He is also a member of the Editorial Advisory Board for The American Gardener. (For more on Kelaidis and his wife, Gwen, see "Love on the Rocks" in the January/February 1998 issue of The American Gardener).

Bad News for Fruit Growers

Two imported diseases are posing serious threats to American fruit growers and home orchardists. Citrus canker, a highly contagious bacterial disease, has infected orange, grapefruit, and lime trees in southern Florida, and it's spreading north. Plum pox, the most destructive viral disease of stone fruits in Europe, was detected last fall in Adams County, Pennsylvania. There is no known cure for either disease.

Citrus Canker. This is the third and most serious outbreak of citrus canker in southern Florida in the past 100 years. The present strain, apparently imported from Asia, was first detected in a backyard in Miami in 1995. The disease has now spread to three Florida counties-Dade, Broward, and the south end of Palm Beach. Symptoms of the disease are small, round, blisterlike lesions that appear on fruit, leaves, and twigs of infected trees. As they age, leaf lesions turn tan with a yellow halo, eventually leaving holes in the leaf; fruit lesions become corky. As the disease advances, fruit production drops off and the tree ultimately dies. 

Spread by wind, rain, and contaminated tools, citrus canker can move quickly to infect an entire orchard or the citrus trees in a neighborhood. Overhead irrigation also facilitates local spread of the bacteria, while the transportation of infected fruit and plants can spread disease over much greater distances. The only known way to halt its spread is to eradicate infected trees. Once a tree has been positively diagnosed with the disease, that tree and any other citrus trees within a 600-yard radius must be removed. Over 500,000 trees have already been cut down and destroyed in the Miami and Fort Lauderdale areas. Inspectors and growers continue to monitor citrus trees for symptoms and track the disease's movement.

Plum Pox. Originally observed in the early 1900s in Bulgaria, plum pox has spread throughout Europe, where it is known as sharka. It infects stone fruits such as peaches, plums, apricots, nectarines, almonds, and cherries, as well as ornamental Prunus species. It can also infect other hosts, including zinnias, white clover, and some weeds that belong to the nightshade family. Spread over short distances by more than 20 species of aphids, plum pox can travel much great distances in infected plant stock, which is the most likely way it was introduced to Pennsylvania. Though the disease is well known in parts of Africa and in Chile, until last fall, plum pox had not been detected in the United States. 

As of this March, 218 acres of infected trees located in the Huntington and Latimore townships of Adams County, Pennsylvania, had been identified and destroyed. Though they have yet to pinpoint the initial source of infection, researchers suspect it was introduced on nursery stock-perhaps an ornamental host. Researchers believe that the virus has probably been in Adams County-Pennsylvania's largest fruit-producing county-for at least three years, but was not recognized immediately. Symptoms include rounded spots or "pox" on fruit, stems, leaves, and seeds. Initial symptoms resemble a nutrient deficiency or insect damage. Infected fruit, while not harmful to humans, becomes disfigured and unmarketable. Yields of infected trees are significantly reduced-as much as 80 to 100 percent. 

Pennsylvania ranks fourth among states in production of stone fruit, and is taking an aggressive approach to preventing the spread of plum pox. The United States Department of Agriculture and its Pennsylvania counterpart have teamed up in an effort to control and eradicate the virus where it has been detected by destroying infected trees, preventing the movement of potentially infected plants from the area where the disease has been detected, and monitoring for new outbreaks. The Pennsylvania Department of Agriculture will test stone-fruit orchards in the state as well as residential trees in the infected area in an effort to detect additional infestations.