University of Kentucky HortMemo

HortMemo - A University of Kentucky Cooperative Extension Service Newsletter for the Kentucky Nursery/Landscape Industry
Current 2017 HortMemo below

by Winston C. Dunwell, Professor - Nursery Crops Development Center

UK Department of Horticulture

To subscribe send an e-mail to cforsyth@uky.edu or call Christi, 270.365.7541 x 221.

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December 4, 2017

Kentucky Nursery & Landscape Association announced the KNLA Spring Training and Trade Show dates are January 24-25, 2018 and the location, Ramada Plaza Louisville Hotel and Conference Center, 9700 Bluegrass Parkway Louisville KY 40299.  Some changes have been made to make it better; all programs will be in rooms separate from the trade show to give more room for the trade show and reduce the noise during educational programs.

Allium 'Millenium' is the 2018 Perennial Plant of the year. Perennial Plant Association (PPA) announcement is at http://www.perennialplant.org/index.php/component/k2/item/198-2018-perennial-plant-of-the-year .Plant Delight’s Nursery described it in their catalog “We are pleased to have introduced this stunning Allium nutans hybrid in 2000, from breeder Mark McDonough (aka Mr. Onion). Allium 'Millenium' represents several generations of breeding (onions) and is head and shoulders above any other allium we grow. The compact 1' tall x 1' wide clump of narrow, glossy green, deer-resistant leaves is topped for over a month in late summer with 2" rosy-purple flower heads, which attract flocks of onion-loving butterflies. We grow Allium 'Millenium' in several locations and have never seen any sign of a stray seedling...garliccimo! For years, we have used the spelling, Millennium, but Mark actually registered it as Millenium, so we've corrected our spelling.”

The Boxwood Blight Best Management Practices online viewable or downloadable publication sponsored by AmericanHort, Horticulture Research Institute and the National Plant Board was revised to Version 2.0 in September 2017. The statement; Updates to the recommendations will be made as more information regarding the disease and its management comes to light may require checking the site occasionally or watching for notices in HortMemo or other publications. https://hortknowledgecenter.org/getattachment/7068c31f-fee0-4541-bf4a-ac89350be97b/BoxwoodBlightBMPs2017.pdf?lang=en-US
This was another of the posts Matthew Chappell made to his Nursery & Landscape Insider Newsletter you can subscribe to by going to:  https://www.ballpublishing.com/bpsubscriptions/newslettersignup.aspx?newsletter=nurserylandscapeinsider

Joe Neal and weed oriented members of the Southern Nursery Integrated Pest Management (SNIPM) working group conducted weed control research in container nurseries. To share the results the group produced publications, a field day and webinar.  The information showed “that if those growers adopted those practices, which would reduce their hand weeding costs by an average of 36 percent” One can get to their information via the Southern IPM E-mail Newsletter.

An interesting presentation at the American Society for Horticultural Science Annual Conference as a YouTube video: The Effect of Oxygenation of Irrigation water on Rooting and Plant Growth of Bedding Plants. Erin Yafuso and Paul Fisher (University of Florida

It is time to start preparing to trap for ambrosia beetle in late winter. See Dr. Zenaida Viloria’s article on How to Build a Trap for Ambrosia Beetles in the January 2017 Nursery Listserve.

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September 11, 2017



KNLA’s Summer Retreat - Leadership Forum and Marketplace will be September 21, 2017 at Springhouse Gardens, 6041 Harrodsburg Road, Nicholasville, KY 40356.  It will be another great event organized by the very active and pro-green industry KLNA Board of Directors.  If you have never been to Springhouse Gardens it alone is worth the visit, add in the presenters and vendors and it will be a “WORTHY” day.  For more information check the website, http://knla.org/calendar-events or for the schedule see http://knla.org/wp-content/uploads/2015/05/RevisedSchedule.pdf a great group of speakers has been gathered to offer CEU’s: Pesticides - 7 CEU’s (3 Specific and 4 General); Arborist - 4 CEU’s; Landscape Architect - 5 CEU’s and the subjects and presenters are:
1. “Trials & Tribulations . . . How a Plant Becomes a Proven Winner” - Tom Ewing, Proven Winners
2 .“Tried And True Shrubs For The Landscape” - Jane Beggs - Joles, Spring Meadow Nursery
3. “High Impact Perennials For The Landscape” - Jeremy Windemuller, Walter’s Gardens
4. “Stunning Combinations For Long Lasting Annual Color” - Zeke Cooper, Grounds
Property Manager, Caesars Entertainment Corporation, Harrah’s Cherokee Casino Resort.
5. “Putting It All Together - Combining Trees, Shrubs, Perennials
& Annuals for Year Round Beauty” - Richard Weber, Springhouse Gardens
6. “Making a Statement With Trees” - Speaker TBA;
7. “Landscaping on Mackinac Island . . . How top quality materials help overcome the unique challenges of a ‘motor vehicle-free’ island” - Jack Barnwell, Barnwell Landscape and Garden Services, Mackinac Island & C3 Gardens, Florida.

Eastern Region International Plant Propagator’s Society (IPPS-ENA) annual conference, October 11-14, 2017, will include tours to several well-known nurseries that have embraced some of the highest technological advances seen in the United States. Speakers, as always, are leaders in the nursery/landscape industry.  The deadline for registering is later in the month.  The host hotel is Holiday Inn Grand Rapids Downtown, 310 Pearl St NW, Grand Rapids, MI 49504. For more information contact  Margot Bridgen or visit the website http://ena.ipps.org/event/Regional-Events/2017-Eastern-Region-Annual-Conference-Grand-Rapids-Michigan/QjJFSFlBJTNEJTNE. Margot is the IPPS ENA Region Executive Secretary/Treasurer, 1700 North Parish Dr., Southold, NY 11971; 631.765.9638; Fax, 631.765.9648; e-mail, ippser@gmail.com ; url, http://ena.ipps.org

KNLA’s August 17, 2017 Bus Tour was a great event; just ask anyone who attended or the hosts; Kris Stone at Boone Arboretum, Steve Foltz and the Cincinnati Zoo & Botanical Garden crew, Spring Grove Cemetery horticulturist Brian Heinz or Greg Ammon, Ammon Wholesale Nursery. I had the opportunity to do just that recently and all raved about the KNLA organization and the interest of those who attended.  Hopefully, the KNLA Board will do it again.

Flowering Dogwood Diseases, Plant Pathology Factsheet PPFS-OR-W-06, by Nicole Ward Gauthier and Sarah Stoltz contains a great presentation of pictures and text on our favorite flowering tree and the diseases that influence its health and floral display. Check it out.  http://plantpathology.ca.uky.edu/files/ppfs-or-w-06.pdf

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July,13, 2017



It seems there are lots of things happening in resources and meetings that has resulted in HortMemo 5 so close to the last HortMemo 4. Like Cultivate’17


The KNLA 2017 Bus Tour of Northern Kentucky and Cincinnati is Thursday, August 17, 2017.  Meets and starts with a tour of Boone County Arboretum 9190 Camp Ernst Road
Union, KY 41091 then take the bus to tours of: Cincinnati Zoo and Botanical Garden , Spring Grove Cemetery, Ammon Nursery, then return to Boone County Arboretum for dinner and speakers. To register go to https://www.eventbrite.com/e/2017-knla-bus-tour-tickets-33814956445

The 2017 Southeastern US Pest Control Guide for Nursery Crops and Landscape Plantings https://content.ces.ncsu.edu/southeastern-us-pest-control-guide-for-nursery-crops-and-landscape-plantings was a project of the Southern Nursery IPM Working Group (SNIPM) and collaborators. It is an outstanding publication, long needed, discussed and now reality. Drs. Nicole Ward Gauthier and Matthew T. Springer, University of Kentucky, made significant contributions.  The guide is intended to provide up- to-date information about pest control products (Matthew has a chapter on wildlife management) in nursery crops and ornamental landscape plantings, and as a supplement to the more comprehensive integrated pest management (IPM) manuals for trees and shrubs available for download from the SNIPM web site, https://wiki.bugwood.org/SNIPM . Recommendations for the use of agricultural chemicals are included in this publication as a convenience to the reader. The information is intended as a guide to aid in pest control decision-making and not a substitute for reading and following the directions and guidelines on the pesticide label.

The most recent of the SNIPM publications was announced by the lead editor, Matthew Chappell, UGA Associate Professor – Nursery Production in his Grower Talks Nursery & Landscape Insider:  New IPM Guide: From yours truly comes a brand new integrated pest management resource!
IPM for Shrubs in Southeastern U.S. Nursery Production Volume II is the third book released by the Southern Nursery Integrated Pest Management Working Group (SNIPM) – although the content is applicable across North America. The book covers management practices, abiotic stressors, pathogens, insect pests and weed management strategies in five major ornamental genera including hydrangea, loropetalum, holly, rhododendron (including azalea) and Indian hawthorn. https://wiki.bugwood.org/IPM_Shrub_Book_II  We would appreciate you taking a moment when visiting the publication to take the survey so the next effort will be even more useful to you.
To Subscribe to Matthew’s Nursery & Landscape Insider go to the page and click on the subscribe button. http://www.ballpublishing.com/NurseryLandscapeInsider/CurrentNewsletter.aspx Matthew and Grower Talks already have - 28,542 subscribers as of July 8, 2017.

This announcement appeared in Kentucky Pest News and provides a valuable resource:
Relative Effectiveness of Various Chemicals for Disease Control of Ornamental Plantings (PPFS-GEN-13) The Southern Nursery Integrated Pest Management (SNIPM) working group is comprised of Extension professionals from several southern states, including Kentucky.  The SNIPM group collaborates on multi-state nursery crop projects, such as the Relative Effectiveness of Various Chemicals for Disease Control of Ornamental Planting.  This publication is a joint effort of the University of Kentucky, University of Georgia, California Polytechnic State University (San Luis Obispo, CA), and the University of Tennessee.  First published in October 2014, this newly revised and expanded version is now organized by FRAC group and provides efficacy information for fungicides applied to manage sixteen common nursery, greenhouse, and landscape ornamental diseases.
Relative Effectiveness of Various Chemicals for Disease Control of Ornamental Plantings (PPFS-GEN-13) is available online. In case of difficulty with the link copy and paste site to your search http://plantpathology.ca.uky.edu/files/ppfs-gen-13.pdf
For additional publications on ornamental diseases, visit the UK Plant Pathology Extension Publications webpage.
Nicole Ward Gauthier, Extension Plant Pathologist

Carey Grable keeps posting to the UKRECHort YouTube Channel. A couple of recent ones:
BEE CONSERVATION in the Urban Landscape by Bernadette Mach is worthy on the UKRECHort YouTube channel. Bernie shared great information from Dan Potter’s UK Lab https://www.youtube.com/watch?v=S3GPNpBdhnQ&t=398s
Osmanthus for the Mid-South by USDA Plant Breeder Lisa Alexander. Lisa is looking for a hardier Osmanthus with great ornamental characteristics. https://www.youtube.com/watch?v=_2mxZJuC21I&t=250s Recent conversations with Kentucky Plants people indicates that Osmanthus heterophyllus 'Goshiki' is doing well in Kentucky landscapes and can be found at garden centers.

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July 5, 2017



The Southeastern US Pest Control Guide is a valuable publication for anyone in Nursery/Landscape https://content.ces.ncsu.edu/southeastern-us-pest-control-guide-for-nursery-crops-and-landscape-plantings/complete-southeastern-us-pest-control-guide.pdf


Many nursery owners are diversified farmers and may find benefit from The Farmer's Resource for Grain Production in Kentucky mobile-friendly web page http://www.kygrains.info If you would rather get Tweets you may follow @kygrains or easier still follow the Tweets of UK Professors Chad Lee @kentuckycrops and Carrie Knott @kygrains


To the nursery landscape industry and orchardists, a reminder Nicole Ward Guathier Twitter account @Nicole_WardUK https://twitter.com/nicole_warduk?lang=en keeps us up on Nursery, Landscape and Fruit plant pathology

2018 Midwest Green Industry Experience (MGIX) welcomes the Kentucky Nursery and Landscape Association. The Kentucky Nursery and Landscape Association (KNLA) will welcome its members to the 2018 Midwest Green Industry Experience in Columbus, OH, in lieu of holding the annual KNLA Spring Training and Showplace.  MGIX 2018 set to take place January 15-17, 2018 in Columbus, Ohio http://www.mgix18.com  for more information follow the KNLA Facebook page. https://www.facebook.com/Kentuckynurseryandlandscapeassociation


KNLA’s 2017 Bus Tour on August 17, 2017 starts at 8:00 am EDT with a Kristopher Stone led tour of Boone County Arboretum, 9190 Camp Ernst Road, Union, KY 41091 load the buses to other stops on the tour: Cincinnati Zoo & Botanic Garden lead by Stephen Foltz; Spring Grove Cemetery with Box Lunch and Tour with Brian Heinz/Stephen Foltz; Ammon Wholesale Nursery Nursery Tour - see their growing operation!; back to Boone County Arboretum for Dinner and Speakers at the Arboretum. https://www.eventbrite.com/e/2017-knla-bus-tour-tickets-33814956445

I was working on the next SNIPM Shrub book holly chapter and learned the 2017 Holly of the Year, Ilex glabra , Inkberry or Gallberry an evergreen native to most of the eastern US and southern Canada, and is hardy in Zones 5-10. The leaves are glossy and spineless, but with finely toothed margins. Inkberry forms a rounded, multistemmed shrub, typically 3-10’ (1-3 m) tall and wide, though most commercially available cultivars reach only about 5’ and can be sheared if desired. Given these properties, inkberries are suitable for a wide range of landscape uses, including foundation planting, screening, and informal hedges. They thrive in full sun to part shade, and are tolerant of wet soils. Inkberries are a mostly carefree garden plant, and make a valuable contribution to the natural landscape. They flower in late spring on new growth, and their small white flowers are an important source of nectar for foraging honeybees. Female plants produce pea-sized black fruits, which are not especially conspicuous but are highly attractive to birds in winter.
Many named varieties of Ilex glabra can be found in your local garden center; some of the best cultivars include ‘Shamrock’, ‘Compacta’, ‘Densa’, ‘Nigra’, ‘Chamzin’ (NordicTM), and the recently-introduced ‘Nova Scotia’. Direct quote from Holly of the Year 2017 http://www.hollysocam.org/year.htm archives will be  http://www.hollysocam.org/year_17.htm


I added a brief descriptive page with pictures to KYNatives on the not so common Kentucky Native Frasera caroliniensis Walter - American Colombo



Carey Grable, Extension Associate for Nursery Crops and our go-to videographer and video editor has posted a new video to the YouTube UKRECHort Channel. It is USNA Breeder, Lisa Alexander's work on finding a hardy Osmanthus. See https://www.youtube.com/watch?v=_2mxZJuC21I&t=268s By the way, Tony Nold, Richard Weber and other Kentucky Landscape Designers and Architects are selling and using a variegated Osmanthus, Osmanthus heterophyllus 'Goshiki', successfully in Kentucky.

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April 11, 2017



Zenaida is monitoring and scouting for ambrosia beetles again in west Kentucky and will keep you up on results through Kentucky Pest News https://kentuckypestnews.wordpress.com/, the Nursery Listserve http://nursery-crop-extension.ca.uky.edu/listserv and here in HortMemo.  The week of April 3rd marked the first large number of Granulate Ambrosia beetles in the traps in Calloway, Graves, Caldwell and Todd Counties of west Kentucky.

Nicole Ward Gauthier sent out the following information for Orchardists but much of it applies to crabapples, hawthorn and serviceberry.

Fire Blight Alert and Risk Map Overview
By: Nicole Ward Gauthier, Extension Specialist 

Apple trees are blooming throughout the commonwealth. Infection by the fire blight bacterium occurs during bloom, thus, protectant antibiotics should be applied when risk is high. 

Risk for infection can be assessed using the Fire Blight Disease Prediction Model. Growers can assess local risk by selecting their county and orchard history. This model incorporates the previous 4 days of weather data plus adds a 7-day forecast for estimating leaf wetness and temperature (thereby estimating risk for bacterial growth and infection). There are 66 Mesonet weather stations throughout Kentucky, thus, weather information for the model is based on data from the closest weather station. For a mobile (phone or tablet) friendly version of this site, visit http://weather.uky.edu/dim.html.

Remember that apple and pear trees must be in bloom for predictions to be accurate. The map overview presented here indicates fire blight risk as of April 10, 2017 (Figure 1).  According to the current assessment, risk is low to marginal across the state due to low humidity during the past several days.  A rain event, however, can increase that risk.  Growers are encouraged to check the model regularly for the most accurate analyses and county-specific forecasts.

Information regarding prevention and management of fire blight can be found in:
Commercial Fruit Pest Management Guide (ID-232)
Backyard Apple Disease Management Using Cultural Practices (PPFS-FR-T-21)
Fire blight (PPFS-FR-T-12)
Fire blight of Apple (Video)

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February 3, 2017



Dr. Chris Ranger, Research Entomologist Horticultural Insects Research Lab, USDA-Agricultural Research Service, Wooster, OH will be giving a seminar on Ambrosia Beetles damaging nursery and orchard trees in west Kentucky. The seminar will be at the UKREC, 1205 Hopkinsville Street, Princeton, KY 42445 on February 15, 2017 at 8:30 AM CST.  http://www2.ca.uky.edu/HLA/Dunwell/RangerAmbrosiaSeminarUKRECHort.pdf


Dr. Zenaida Viloria, Extension Associate for Nursery Crops, with UKREC Horticulture! has published a timely article on How To Build a Trap for Ambrosia Beetles in the January 2017 Nursery Listserve. https://NCER.ca.uky.edu/listserv for the article go to:
http://j.tinyurl.com/zxp7hwk  zenaida.viloria@uky.edu


From Kentucky Pest News. This might be useful to those growing crabapples (Malus), serviceberry (Amelanchier), and pears (Pyrus). The Extension publication, An IPM Scouting Guide for Common Problems of Apple in Kentucky, was first introduced in 2014 as an online/paper version. In order to improve access to this important scouting guide, a mobile website has been developed. The Apple Scout Website (http://applescout.ca.uky.edu) is now available for grower, agent, and homeowner use. The website can be easily accessed from any phone, tablet, iPad, or computer.

The Organic Association of Kentucky will hold its sixth annual conference focusing on organic farming and living, March 3-4, 2017 at Paroquet Springs Conference Center, Shepherdsville, KY. The keynote speaker is American novelist, poet, environmental activist, cultural critic, farmer, and Kentucky native Wendell Berry. Kentucky farmer and researcher Dr. Greg Halich will talk about the key to profitability with grass-fed beef. Diversified farmer John Bell of Elmwood Stock Farm will present his 8-year rotation plan on adding fertility and creating an extra revenue stream with livestock. For more information go to http://www.oak-ky.org/2017-conference there is a significant discount for those that register before February 10, 2017.


The Kentucky Nursery and Landscape Association inducted me into the KNLA Hall of Fame.  What an honor to be included with the best-of-the-best leaders in Kentucky’s nursery/landscape industry and the KNLA. Thank you to all who supported me over the years. http://www2.ca.uky.edu/HLA/Dunwell/DunwellKNLAHallofFame.pdf

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January 17, 2017


The Kentucky Nursery and Landscape Spring Training & Showplace – 2017 conference/educational programs and trade show is January 25-26, 2017 at the Ramada Plaza Louisville Hotel and Conference Center, 9700 Bluegrass Parkway Louisville KY 40299. One can register and view the program online at http://knla.org/event/knlas-spring-training-showplace or be a walk-in the day of.  See you there!


Richard “Dick” Ammon passed away at age 87, January 1st, 2017.  He was a leader in the nursery/landscape industry from the moment he established Ammon Nursery.  Past-President of the KNLA (1969) and a founding member of the committee that established the Kentucky Certified Nurseryman program. His contributions to the industry have been significant. Dick served, as President of Southern Nursery Association (SNA - 1974), was a founding director of the Sidney B. Meadows Scholarship Endowment Fund (1989), and served as President of the fund. For a brief obituary (brief in that so many of us have wonderful memories of Dick) see http://www.sna.org/page-975977/4519224


newTerrain, a Ball Publishing newsletter, on “Functional Plants, Functional Landscapes” has contained some interesting information. You can see the most current edition at http://www.ballpublishing.com/NewTerrain/CurrentNewsletter.aspx and subscribe by clicking on the subscribe button or by going to:


From Kentucky Pest News: Two dicamba formulations, XtendiMaxTM (Monsanto) and EngeniaTM (BASF), received federal EPA approval in December for use with RoundupReady2Xtend soybean.  In addition to federal registration, a pesticide must also be registered and approved within a state before it can be sold.  The XtendiMaxTM product received state approval in early January for applications in Kentucky.  The EngeniaTM product is still pending state approval, but it is anticipated in the near future.  These products can be applied before or immediately after planting Roundup Ready 2 Xtend Soybeans or as an in-crop application from emergence (cracking) up to and including the beginning bloom (R1 growth stage of soybeans).  Because of the potential for injury of off-target plants there are rules for application in supplemental labels. In Kentucky, applicators will need to be extra cautious about making an application where sensitive crops such as tobacco, grapes, landscape plants, fruit trees, vegetables, greenhouses or home gardens are growing nearby. https://kentuckypestnews.wordpress.com/2017/01/10/new-dicamba-products-receive-approval-for-use-on-rr2xtend-soybean
To subscribe or read Kentucky Pest News go to http://plantpathology.ca.uky.edu/extension/kpn

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