Tennessee Greentimes - Spring 2013

VOL. 14/NO. 1

Spring 2013

Best& Beautiful The

Annuals & Perennials from the UT Gardens A New Disease: Downy Mildew of Impatiens Plus, Highlights from the TNLA Green Industry Expo and TNLA’s 2013 Winter Education & Exhibits

Table of Contents

Green Gatherings Highlights from the TN Green Industry Expo and TNLA’s 2013 Winter Education

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VOL. 14/NO. 1

Spring 2013

Cover Story UT Gardens’ 2012 Best & Beautiful Annuals and Perennials

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DEPARTMENTS From the President, Bill Seaton.........................................................................................6 News from TNLA................................................................................................................8 TNLA New Members........................................................................................................10 Calendar of Events............................................................................................................22 Index of Advertisers..........................................................................................................22

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Disease Spotlight A New Disease: Downy Mildew of Impatiens

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The Tennessee Nursery and Landscape Association serves its members in the industry through education, promotion and representation. The statements and opinions expressed herein are those of the individual authors and do not necessarily represent the views of the association, its staff, or its board of directors, Tennessee GreenTimes, or its editors. Likewise, the appearance of advertisers, or their identification as Tennessee Nursery and Landscape Association members, does not constitute an endorsement of the products or services featured in this, past or subsequent issues of this quarterly publication. Copyright ©2013 by the Tennessee Nursery and Landscape Association. Tennessee GreenTimes is published quarterly. Subscriptions are complimentary to members of the Tennessee Nursery and Landscape Association Third-class postage is paid at Nashville, TN. Printed in the U.S.A. Reprints and Submissions: Tennessee Green Times allows reprinting of material. Permission requests should be directed to the Tennessee Nursery and Landscape Association.

We are not responsible for unsolicited freelance manuscripts and photographs.

Contact the managing editor for contribution information. Advertising: For display and classified advertising rates and insertions, please contact Leading Edge Communications, LLC, 206 Bridge Street, Franklin, TN 37064, (615) 790-3718, Fax (615) 794-4524.

From the President Bill Seaton

In

the time of Caesar, the month of Martius began the New Year. Although today’s calendar has March, named to honor the Roman god Mars, as the third month of the year, it still marks a beginning — the beginning of spring. Most often depicted as the god of war, Mars was also revered as a guardian of agriculture, ensuring fertility and protecting the crops for a bountiful harvest.

Through my service on the TNLA board, I can readily identify with the role of Mars in safeguarding the “original” green industry. We are challenged daily with the uncertainties of wind, weather, labor and legislation while we fight for survival in an ever-changing marketplace. I believe it is imperative that we, the membership of the Tennessee Nursery and Landscape Association, embrace our role as guardians and protectors of our industry.

As an organization, our collective best interests were well served last year through a number of accomplishments that deserve specific acknowledgement. The bold leadership of Michael Kassees led us back home as we held the inaugural Tennessee Green Industry Exposition in Nashville. Matt Dawson was tasked with securing the keynote speaker and featured presenters, and he was key in organizing the educational program.

Louree Walker and Pam Stern were steadfast in working out all the details and keeping the train on the tracks. And, of course, the event’s attendees were a crucial element in making it a great success. We are counting on you to return and encourage someone new to participate for TNGIE 2014!

Essential to the establishment and success of the East Tennessee Chapter of the TNLA has been a committed core of enthusiastic supporters from a cross section of the industry. In Knoxville, we are fortunate to have the resources of The University of Tennessee in our backyard, and we are blessed with passionate faculty members as well as dedicated Extension agents and specialists. As funding continues to shrink, the interdependent relationship of industry, extension and academics is more critical now than ever before. Our partnerships with Tennessee Tech and Tennessee State University are equally as important, and we need to work hard at sustaining and nurturing these critical relationships. We need to be ever vigilant in keeping current with legislative issues and letting our representatives know how critical the TSU Nursery Research Center is to maintaining Tennessee’s role as a leader in the nursery industry.

We can make great strides in protecting our industry and show true leadership by practicing and promoting some simple yet essential principles: • Actively support the education of our peers and those who use our products and services.

• At all times advocate the best horticultural practices and standards.

• Promote professionalism and cooperation within our industry.

• Enhance good faith and goodwill by supporting the highest standards of business ethics and integrity.

• To strive in all ways to support the best interests of our membership and the TNLA. I have a challenge for each of you reading this: Renew your role as a guardian of agriculture. Help us grow our organization by bringing in a new member who shares our principles of stewardship and recognizes them as a path to success.

Let us embrace our role as a modern-day Mars and become enthusiastic guardians of agriculture. By doing so, we can ensure a bountiful (and profitable) harvest!

TNLA Would like to

Thank

the following companies for being

Membership Sponsors

Gold Membership Sponsors Barky Beaver Mulch & Soil Mix, Inc. BWI of Memphis Envirotexx, LLC Randall Walker Farms Swafford Nursery, Inc. Tennessee 811

Silver Membership Sponsors Allen Landscape Management, LLC Common Grounds Landscape Management, Inc. Stowers Cat Triple SSS Farm

Bill Seaton

Warren County Nursery

2013 TNLA President

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The Tennessee Greentimes is the official publication of The Tennessee Nursery & Landscape Association, Inc. 115 Lyon Street McMinnville, Tennessee 37110 (931) 473-3951 Fax (931) 473-5883 www.tnla.com Email: mail@tnla.com Published by Leading Edge Communications, LLC 206 Bridge Street Franklin, Tennessee 37064 (615) 790-3718 Fax (615) 794-4524 Email: info@leadingedge communications.com Editors Dr. Bill Klingeman Dr. Amy Fulcher Associate Editors Dr. Donna Fare Dr. Nick Gawel Mr. Mark Halcomb Dr. Frank Hale Mr. Gray Haun Dr. John Sorochan TNLA Officers President Bill Seaton TruGreen LandCare 1st Vice President Matt Dawson Natural Creations, LLC 2nd Vice President Jeff Harrell Tennessee Valley Nursery 3rd Vice President Kim Holden Holden Nursery Secretary-Treasurer Randall Walker Randall Walker Farms Associate Director Tony Graham Tractor Supply Company Ex-Officio Michael Kasees Forest Nursery Co., Inc. Executive Director Louree Walker Administrative Assistant Pam Stern

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News from TNLA

Meet Your New TNLA Leaders!

At

TNLA’s Business Meeting, held on February 18 during the 2013 Winter Education Program in Pigeon Forge, TN, the following new TNLA officers and directors for 2013 were elected and installed.

President

2nd Vice President

Bill Seaton TruGreen LandCare 3333 Regal Drive Alcoa, TN 37701 (865) 970-3835 williamseaton@ landcare.com

Jeff Harrell Tennessee Valley Nursery 145 Tennessee Valley Dr. Winchester, TN 37398 (931) 967-4541 jharrell77@bellsouth.net

1st Vice President

3rd Vice President

Matt Dawson Samara Farms 3952 Stewarts Lane Nashville, TN 37218 (615) 248-7757 matt@samarafarms.com

Kim Holden Holden Nursery 3615 Strong Road Mascot, TN 37806 (865) 933-7165 holden58@aol.com

TNLA President Bill Seaton (left) presents a plaque of appreciation to Ex-Officio Michael Kassees.

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2013 TNLA Board of Directors Seated (left to right): First Vice-President Matt Dawson, President Bill Seaton and Second Vice-President Jeff Harrell. Standing: Secretary-Treasurer Randall Walker, Third Vice-President Kim Holden, Associate Director Tony Graham and Ex-Officio Michael Kassees.

SecretaryTreasurer

Ex-Officio

Randall Walker Randall Walker Farms 8240 Manchester Hwy. Morrison, TN 37357 (931) 635-9535 rwalkerfarms@blomand.net

Michael Kassees Forest Nursery Co., Inc. 2362 Beersheba Hwy. McMinnville, TN 37110 (931) 473-2133 forestnsy@blomand.net

Associate Director Tony Graham Tractor Supply Co. 200 Powell Place Brentwood, TN 37027 (615) 440-4474 tgraham@tractorsupply.com

TNLA President Bill Seaton (left) presents a photo collage to outgoing Director John Watson in commemoration of his five years of service on the TNLA board, including serving as 2011 President.

TNLA President Bill Seaton (left) presents a photo collage to outgoing Director Mary Pennington in commemoration of her two terms of service on the TNLA board (2007–2009 and 2011–2013).

New Members

Welcome,

TNLA New Members!

ACTIVE MEMBERS Green Effects | Matt Arand P.O. Box 8943 | Chattanooga, TN 37414 GreenStar Lawns | James Grimes P.O. Box 23694 | Knoxville, TN 37933 Morris Nursery & Landscapes, Inc. (reinstated) | Dan Morris 2108 Hollywood | Jackson, TN 38305 The Grounds Masters | Donald Smego P.O. Box 22774 | Knoxville, TN 37933 Wilson Fine Gardens, LLC | Greg Wilson 3900 Greenleaf Ave. | Knoxville, TN 37919

ASSOCIATE MEMBERS Anderson Mulch & Soil, LLC Eddy Burnette | 1115 Columbia Avenue Tompkinsville, KY 42167 Bushwacker TN | Cliff Davidson 363 Collinwood Dr. | McMinnville, TN 37110 Extreme Mulch, LLC | Jonathan Smith 7216 Haley Industrial Drive Nolensville, TN 37135 Grand Ole Opry (reinstated) | Mac Smith Senior Operations Mgr. 2804 Opryland Drive | Nashville, TN 37214 Greenway Landscape Supply | W.C. Gunter 805 Cane Hollow Road Pigeon Forge, TN 37863 Landmark International Trucks Andy Jablonski 4550 Rutledge Pike | Knoxville, TN 37914 New Market Agricultural Equipment Co. Lee Hammons 501 New Market Road New Market, AL 35761 Stover Manufacturing, LLC | Jeff Harris 919 Alexander Ave. | Port Orange, FL 32129 Tractor Supply Co. | Tony Graham 200 Powell Place | Brentwood, TN 37027

AFFILIATE MEMBERS Traci Puckett 7500 Hook Ridge Road | Monroe, TN 38573

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Green Gatherings

Tennesee Green Industry Expo January 3–4, 2013 • Nashville, TN

Congratulations to the TGIE Best of Show Booth Winners Thanks to Our Generous TGIE Sponsors!

PLATINUM SPONSOR 1st Place Green Goods Plantation Tree Company (Selma, AL)

1st Place Hard Goods Tennessee Valley Tractor and Equipment (McMinnville, TN)

Tennessee Dept. of Agriculture (Nashville, TN)

GOLD SPONSORS Forest Nursery Co., Inc. (McMinnville, TN) Gowan, USA (Auburn, AL) Harrell’s Fertilizer (Nashville, TN) Randall Walker Farms (Morrison, TN) Samara Farms (Nashville, TN)

2nd Place Green Goods Walker Nursery Company (Morrison, TN)

2nd Place Hard Goods General Equipment Co. (McMinnville, TN)

Swafford Nursery (McDonald, TN) Trivett’s Nursery (McMinnville, TN) Walker Nursery Company (McMinnville, TN)

3rd Place Green Goods Palms Unlimited (Mobile, AL)

3rd Place Hard Goods Dickens Turf & Landscape Supply (Nashville, TN) tennessee greentimes

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Green Gatherings

Highlights from

TNLA’s WInter Education & Exhibits in Pigeon Forge, TN, February 18–19, 2012

Congratulations to TNLA’s 2013 Award Winners!

(Shown below with 2013 TNLA President Michael Bill Seaton)

Wholesale Nurseryman of the Year Tim Gallagher Heather Farms Nursery Morrison, TN

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Young Nursery Professional of the Year Alex Neubauer Hidden Hollow Nursery Belvidere, TN

William James “Bill” Reilly Jr. Salesperson of the Year Tony Morton Morton’s Horticultural Products McMinnville, TN

Landscape Contractor of the Year Reedy Landscaping, Inc. Chattanooga, TN (Gaylon Reedy accepting the award)

Retailer of the Year Willow Ridge Garden Center & Landscaping Oak Ridge, TN (Greg Steele accepting the award, with Florenda Howard and Chris Johnson)

Committee Chair of the Year Dr. Amy Fulcher The University of Tennessee Knoxville, TN

Hall of Fame 2013 Inductee David Hillis Little River Nursery McMinnville, TN

Hall of Fame 2013 Inductee Jack Odom Odom Nursery Company Morrison, TN

Memorial Scholarship Winner Gabriella M. Starr Middle Tennessee State Univ.

Plant and Soil Science

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Green Gatherings

Thanks Also to Our Exhibitors!

A Big Thanks to our 2013 Winter Education Sponsors!

Common Grounds Knoxville, TN John Deere Landscapes Knoxville, TN Tennessee Dept. of Agriculture Nashville, TN

Airtech Tools • Knoxville, TN Classic Groundcovers, Inc. • Athens, GA Dickens Turf & Landscape Supply • Nashville, TN Ewing Irrigation • Nashville, TN Greenway Landscape Supply • Pigeon Forge, TN H & H Farms Machine Co., Inc. • Monroe, NC Hancock Nursery • Kodak, TN J.G. Supplies • Seymour, TN John Deere Landscapes • Knoxville, TN Kinsey Gardens, Inc. • Knoxville, TN

Landmark International Trucks • Knoxville, TN Mid Tenn Turf • Manchester, TN Middle Tennessee Nursery Assn. • McMinnville, TN Mize Farm & Garden • Johnson City, TN Nature’s Best Organics of TN • Knoxville, TN Randall Walker Farms • Morrison, TN Riverbend Nurseries, LLC • Thompson’s Station, TN Samara Farms • Nashville, TN Tennessee Dept. of Agriculture • Nashville, TN Wood Nursery • McMinnville, TN

Memorial Scholarship Winner Kevin Trostel Middle Tennessee State Univ.

Plant and Soil Science (Hort.)

Memorial Scholarship Winner John Adam Turner Tennessee Tech University Agribusiness Management tennessee greentimes

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Cover Story

By Susan Hamilton, Ed.D., Director of the UT Gardens; James Newburn, Assistant Director; Jason Reeves, Curator of the Jackson UT Gardens; Beth Willis, Trials Coordinator; and Holly Jones, Kitchen Garden Manager

Check local nursery availability of listed varieties at the UT Gardens websites: UT Gardens website at http://utgardens.tennessee.edu/ UT Gardens Jackson at http://west.tennessee.edu/ornamentals/

More Best Annuals of 2012 Best in Show — Angelonia Serenita™ Lavender Pink This seed-grown variety bloomed profusely all season. Bright pink blooms were a knockout on tidy, compact plants. (PanAmerican Seed)

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Best New Variety — Evolvulus Blue My Mind™ The vibrant true-blue blooms on this variety were a standout against the silvery foliage all summer long. A trailing growth habit makes it well suited for borders or containers.

(Proven Winners)

Best Repeat Variety — Capsicum ‘Chilly Chili’ This ornamental pepper never fails to delight with its long and showy orange, yellow and red fruits held on top of the plant. Compact growth makes it perfect as a border or container plant.

(PanAmerican Seed)

Top Annuals (alphabetical) Begonia Havana™ Rose This seed-grown begonia boasted heavy blooms all season. Attractive pink blooms did not require deadheading. Like most begonias, this variety was well suited to part shade or shady garden areas. (Takii)

Calibrachoa Superbells® Dreamsicle A carefree annual with dense, healthy foliage and numerous blooms, this spreading variety offered a unique and subtle bloom color. (Proven Winners)

Capsicum ‘Black Olive’ This ornamental pepper demands attention in the garden. Dark-purple foliage is a great backdrop for the purple blooms and, later, for the dark-purple fruits, which mature to bright red. (AAS Winner)

Celosia ‘Arrabona’ The unusual pink and orange hues of this annual were hard to describe but wonderful to behold, with lots of blooms on vigorous, upright plants all summer long. (Fleuroselect Award Winner)

Cyperus Graceful King Tut®

Grasses®

The foliage texture of this grass-like plant provided a wonderful contrast to neighboring flowers. Bold and striking, these are not for the faint of heart! They can reach up to 6' in height and grow well in wet to average soil. (Proven Winners)

Euphorbia Diamond Frost® As usual, this was a carefree, mounding annual. Profusely covered with tiny white blooms, it was a great filler plant that served as a contrast to annuals with larger, more prominent blooms.

(Proven Winners)

Helichrysum ‘Silver Leaf Yellow’ The clusters of bright yellow-orange blooms on this annual are a great contrast to its silver foliage. The spreading habit makes this a great groundcover option. (Suntory)

Ipomoea ‘Sweet Caroline Bewitched’ A can’t-miss annual, sweet potato vine works wonderfully as a groundcover and as a foliage contrast to flowering plants.

This mounding variety boasts dark leaves that resist fading. (Proven Winners)

Lantana Luscious® Tropical Fruit The subtly variegated foliage on this shrubby annual was a perfect backdrop for the soft pink and yellow blooms.

This variety is more compact than many lantanas, staying under 2' tall. (Proven Winners)

Lobularia ‘Blushing Princess’ This ground-hugging annual (Sweet Alyssum) thrived in both part shade and full-sun locations and was covered all summer long with dense panicles of pale lavender (although it didn’t hold its blush as well in the full-sun locations during the heat of summer). (Proven Winners)

Petunia Supertunia® Vista Bubblegum This selection never fails to impress with its vigorous growth, tall mounding habit (up to 18") and large, soft-pink blooms that cover the plants. It sets the standard for vegetative petunias. (Proven Winners)

Salvia ‘Fairy Queen’ The profuse dark-blue and white bicolor blooms on this carefree and vigorous annual were striking in full sun.

(Fleuroselect Award Winner)

Scaevola Surdiva® White This spreading, groundcover annual doesn’t reach even 1' tall, but it is literally covered with delicate, fan-shaped blooms all summer long. (Suntory)

Scoparia Illumina® Lemon Mist Improved Hundreds of tiny yellow blooms give this annual a delicate and airy appearance that belies its rock-steady garden performance.

Try it in containers or as a groundcover edging. (Proven Winners) tennessee greentimes

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Cover Story

Top Perennials of 2012 Solenostemon ‘Vino’

Agastache ‘Blue Boa’

Grown for its foliage rather than its bloom, coleus always provides an excellent contrast to flowering plants in the landscape. This variety has attractive, bold color and texture. (Ball FloraPlant)

Large, showy flower spikes of violet blue distinguish this perennial. It attracts butterflies and hummingbirds.

(Terra Nova)

Tagetes ‘Moonsong Deep Orange’

Echinacea ‘Cheyenne Spirit’

This is an award-winning variety of the popular annual. Remarkably long lasting in the landscape, it was disease-free all season long and remained liberally covered with large, bright blooms against attractive, lacy foliage. (AAS Winners)

Torenia Summer Large Violet

Wave®

This mounding variety covered with vibrant blooms had an unusual “wishbone” structure formed by joined anthers. It performed best in a part-shade location. (Suntory)

Verbena Temari® Cherry Red Huge clusters of bright red blooms were a showstopper combined with vigorous trailing growth. (Suntory)

Zinnia ‘UpTown White Wall’ This variety featured masses of bright white blooms with a yellow eye on upright spreading plants that grew to knee height. (Ball FloraPlant)

Zinnia ‘Zahara Double Fire’ The vibrant orange blooms of this variety absolutely screamed for attention, with numerous blooms on mounding plants that can grow to more than 18" tall. (PanAmerican)

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This variety’s claim to fame is its striking mix of bloom colors, from a warm gold to an intense pink and everything in between. (PanAmerican and Fleuroselect Award Winner)

Gaillardia ‘Mesa Yellow’ A wonderful perennial for our region, this offers bright and cheerful blooms with healthy foliage and profuse blooms throughout the summer. (AAS and Fleuroselect Award Winner)

Geranium ‘Blushing Turtle’ This perennial trial didn’t bloom in its first year, but it certainly made up for that this past year. It was covered in profuse purple blooms from spring to mid-summer, with sporadic blooming after that. (Blooms of Bressingham)

Hibiscus ‘Peppermint Schnapps’ A showstopper in the garden, it boasted enormous white blooms with hints of pink. Large leaves complete the tropical look. It reached 3' to 4' in its first year.

(Blooms of Bressingham)

Hypericum Hypearls™ Renu This plant offers a pleasing mounding habit and numerous bright yellow blooms. Attractive pink berries form after the blooms and extend the season of interest. (Blooms of Bressingham)

Tradescantia Lucky Charm™ This dwarf perennial boasted vivid blue blooms against golden foliage.

The contrast really livened up a partly shaded area of the garden, although this variety can tolerate full sun as well.

(Terra Nova) C

Disease Spotlight

A

By Alan Windham, Ph.D., University of Tennessee Extension; Mark Windham, Ph.D., University of Tennessee AgResearch; and Anni Self, TN Department of Agriculture

very destructive disease of garden impatiens (Impatiens walleriana) in greenhouse production and landscape beds, downy mildew is caused by Plasmopara obducens, a fungal pathogen. Downy mildew of impatiens is significant, as garden impatiens may represent 15% to 20% of bedding plant sales for many garden centers each spring.

In Europe, this disease has essentially ended the use of garden impatiens as a bedding plant. For the past two years, parts of the midwestern and northeastern U.S. have experienced destruction in greenhouse production and landscape

beds that have rivaled the scale of the outbreak in Europe. Downy mildew was first reported in landscape beds of impatiens in the Southeast in 2012 (Photo 1). Due to consecutive years of losses, many wholesale greenhouses are now severely cutting back on the number of impatiens produced for the 2013 season or have eliminated the production of this crop completely. New Guinea impatiens and SunPatiens appear to be resistant.

Downy mildews of bedding plants have been in the news frequently in the last ten years. Different species of fungi can cause downy mildew on vascular

plants. One of the most infamous downy mildews is blue mold of tobacco. In a single season, blue mold can cause extreme damage to tobacco as it moves from the Caribbean to Canada via air currents moving from south to north. In ornamentals, there have been various outbreaks of downy mildew to plants such as Alyssum, Aster, basil, Buddleia, Coleus, Coreopsis, Lamium, rose and Rudbeckia.

Most of these downy mildews are sporadic in occurrence and are caused by several different fungal species. Downy mildew of rose, for instance, is a threat each spring among potted roses that are maintained in cool, humid polyhouses.

Damage to roses can be dramatic. Infected leaves drop prematurely, leaving a stark and denuded plant. It’s important to repeat: downy mildew diseases are caused by several different fungal species. The fungus that infects rose will not infect impatiens and vice versa.

The disease in Tennessee The story of downy mildew of impatiens in Tennessee began in 2004, when a greenhouse in Middle Tennessee noticed that impatiens in hanging baskets were growing abnormally and had unusually light-green leaves with stippling that Photo 1. Defoliation and lack of flowering on garden impatiens (Impatiens walleriana) from downy mildew.

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looked like mite-feeding injury. These infected plants were destroyed. At the time, similar outbreaks were reported across the U.S. After that initial incidence, all was quiet for the next seven years. In 2011, downy mildew of impatiens was observed in landscapes in the Midwest and Northeast U.S., but none was observed in the Southeast. By February 2012, however, ominous reports in Florida told of widespread outbreaks of downy mildew of impatiens not just in production facilities, but also in garden centers and landscape beds. Landscape incidence is of particular concern because downy mildew produces sporangia (spores) that can be blown long distances to infect healthy plants. Indeed, by June 2012, downy mildew was reported in North Carolina and Georgia, and by the end of July, downy mildew was reported in nearly every state east of the Mississippi River.

The first report in Tennessee occurred in mid-June 2012, when infected plants from a landscape bed in Nashville were brought to the Soil, Plant and Pest Center for identification. Within days, downy mildew was identified from garden centers and landscape beds in Memphis, Murfreesboro and Chattanooga. Later that summer, downy mildew was observed in Knoxville and the Tri-Cities area. Many gardeners in the Southeast, however, may have attributed the decline of their impatiens in 2012 to drought, insect damage or other problems.

Signs and symptoms The first easily recognizable symptoms of downy mildew on impatiens are stunted plants, a lack of flowering and premature leaf drop (Photo 2). On closer examination, infected plants may have lightcolored leaves, leaves with stippling similar to spider mite feeding and leaves that are curled abnormally. Generally, by the time these symptoms are noticed, white sporulation of the fungus will also be visible on the underside of infected leaves (Photo 3). Within the canopy, the lowest leaves often exhibit sporulation first.

Plasmopara obducens, the causal fungus of downy mildew on impatiens, produces two types of spores. Sporangia, which are the infective spores that are windblown to other plants, are produced in the white sporulation visible on the underside of leaves. These spores can be spread long distances in air currents.

The second spore type produced by Plasmopara are darkly pigmented,

spherical oospores that form within stem tissues during late fall as plants begin to senesce and decay (Photo 4).

Plant pathologists currently believe that, unlike other downy mildew pathogens that infect ornamentals, downy mildew of impatiens oospores will be able to survive in landscape beds in the Southeast and will infect impatiens planted into those beds during 2013.

Disease Spotlight

Photo 2. Initial symptoms of downy mildew on impatiens are leaf loss and few flowers.

Management and avoidance in greenhouses and landscapes

Photo 3. White sporulation of downy mildew on the underside of an impatiens leaf.

Photo 4. An oospore of Plasmopara in an impatiens stem, which will likely overwinter in the soil in infested landscape beds.

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Management of downy mildew in greenhouses is possible, but it requires an intensive regimen of scouting, environmental controls and timely fungicide sprays. First, employees must be trained to recognize the signs and symptoms of downy mildew.

Second, all incoming plugs or cuttings should be inspected closely. Third, the crop must be examined for signs and symptoms of disease throughout the production cycle. Infected plants should be destroyed. Fourth, leaf wetness should be limited to less than four to five hours per day by careful watering and monitoring relative humidity. Fifth, fungicides should be used preventatively to keep plants healthy. BallHort has published extensively on managing downy mildew.

For specifics on fungicide recommendations see this link: www.ballhort.com/ pdf/ImpatiensDownyMildewGrower Guidelines.pdf.

If downy mildew was present in a landscape bed in 2012, it is recommended

that you do not plant garden impatiens in 2013. In landscapes, the most effective means of avoiding downy mildew will be to shift toward the use of downy mildew-resistant Begonia, Coleus, New Guinea impatiens, SunPatiens and Torrenia plants. If clients insist that you plant garden impatiens this year, first warn them that this could end badly. Second, garden impatiens will require a fungicide drench at planting and repeated, regular sprays during the season. These inputs will significantly increase the cost of maintenance, and even with regular visits, there is no guarantee that the plants will remain healthy through the season.

At this time, there are no garden impatiens (Impatiens walleriana) cultivars that are known to be resistant to downy mildew. It may take years to develop a resistant impatiens. We suspect, though, that there will be demand for garden impatiens in the Southeast this season. Will they remain healthy, or is this the beginning of the end for “Busy Lizzies� in U.S. gardens?

We’ll find out together in 2013. C

Digital Marketplace Scan the QR code: Download your favorite QR reader to your phone and scan the code to learn more about these companies.

June 4

Tennessee Green Industry Field Day Tennessee State University Nursery Research Center McMinnville, TN Contact: 931-473-3951 Fax: 931473-5833 Email: mail@tnla.com www.tnla.com

June 25

Tennessee Green Industry Field Day University of TN Gardens Knoxville, TN Contact: 931-473-3951 Fax: 931473-5833 Email: mail@tnla.com www.tnla.com

July 21–23

August 21–22

November 2–6

Penn-Atlantic Nursery Trade Show (PANTS) Pennsylvania Convention Center Philadelphia, PA Contact: 723-449-4004 www.pantshow.com

October 23–25

November 15–18

August 5–7

October 23–26

PLANET Legislative Day on the Hill Washington, D.C. Contact: 800-395-2522 www.landcarenetwork.org

July 31 – August 1

SNA 2013: Research Conference, Perennial Plant Conference & Tradeshow (Southern Nursery Assn.)

Georgia International July 21–27 Convention Center Perennial Plant Symposium Atlanta, GA Sheraton Vancouver Wall Center Contact: 678-809-9992 Vancouver, Canada www.sna.org Contact: 614-771-8431 Email: ppa@perennialplant.org www.perennialplant.org

Middle Tennessee Nursery Assn. (MTNA) Trade Show Murfreesboro, TN Contact: 931-507-7322 Email: mtna@blomand.net www.mtna.com

PLANET Green Industry Conference Louisville, KY Contact: 800-395-2522 www.landcarenetwork.org

IPPS Southern Region Annual Meeting Athens, GA Contact: 803-743-4284 Email: scplant@bellsouth.net ipps-srna.org

ASLA - Annual Meeting & Expo (American Society of Landscape Architects) Boston Convention & Expo. Center Boston, MA Contact: www.asla.org

School of Grounds Management January 17–18, 2014 and Green Industry Expo Tennessee Green Industry Galt House Hotel and Expo Kentucky Expo Center Music City Center Louisville, KY Nashville, TN Contact: 931-473-3951 Fax: 931-473-5833 Email: mail@tnla.com www.tngie.com

Index of Advertisers Barky Beaver Mulch & Soil Mix, Inc...............................................10 www.barkybeaver.com

Blankenship Farms and Nursery.....................................................21 www.blakenshipfarmsandnursery.com

Boshancee Nursery, Inc.....................................................................22 www.boshanceensy.com

Braun Horticulture..............................................................................20 www.braungroup.com

Coleman Farms...................................................................................21 D & D Agri...............................................................Inside Front Cover Dayton Bag & Burlap Co...................................................................22 www.daybag.com

Ewing Irrigation...................................................................................17 www.Ewing1.com

Hidden Valley Nursery........................................................................21 www.hiddenvalleynursery.com

Hortica.....................................................................................................3 www.hortica-insurance.com

John Deere Landscapes....................................................................13 www.johndeerelandscapes.com

John Holmlund Nursery.....................................................................21 www.jhnsy.com

Jones Nursery Company...................................................................21 www.jonesnurserycompany.com

Kenneth Myers & Son’s Nursery......................................................21 www.littletnnursery.com

Leading Edge Communications.......................................................19 www.leadingedgecommunications.com

Mid Tenn Turf, Inc.......................................................................10, 21 www.midtennturf.com

Motz & Son Nursery.............................................................................7 OHP, Inc................................................................................................21 www.ohp.com

Surface Nursery Inc...........................................................................17 www.surfacenursery.com

Swafford Nursery, Inc........................................................Back Cover www.swaffordnursery.com

Tennessee 811......................................................................................7 www.tennessee811.com

Thomas Nursery..................................................................................21 www.thomasnurserytrees.com

Trivett’s Nursery....................................................................................5 www.trivettsnursery.com

Walker Nursery Co. & Walker Gardens............................................9 www.walkernurseryco.com

Wellmaster Carts................................................... Inside Back Cover 22

tennessee greentimes

Spring 2013

www.wellmaster.ca