MELeaf: A Newsletter From the Horticulture Program, December 16, 2020

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MELeaf: A Newsletter From the Horticulture Program, December 16, 2020

In this issue:

In Case You Missed It: Looking Back at Plant Health in 2020

Looking back at 2020, COVID-19 is, of course, what we think of as the major event of the year, but did you know that before COVID reared its ugly head the United Nations declared 2020 the International Year of Plant Health? Promoting and protecting plant health is what we do at the Horticulture Program, and it is at the heart of what you do as growers and sellers of plants; we all have a role to play. With that in mind, here are some of the Horticulture Program’s, plant health activities that helped protect agriculture, forestry and the environment in Maine.

Emerald Ash Borer - Portions of northern and southern Maine are quarantined due to the presence of emerald ash borer (EAB), a destructive wood boring killer of ash (Fraxinus spp.). During annual surveys the Maine Forest Service detected infestations in seven additional towns. All the new finds are within the existing quarantine area and likely represent natural spread of this insect. EAB was not detected in any towns outside the quarantine areas.

In a bad news/good outcome story, we were notified in August by our partners in the New Hampshire Department of Agriculture, Markets and Food that Lowe’s stores were selling green ash trees from an EAB infested area. By working with Lowe’s and the Maine Forest Service and with assistance from the public in response to a widely distributed press release, we were able to locate 34 of the 40 trees sent to Maine. The trees have been inspected, and all but one tree was voluntarily destroyed. Inspections will continue in future years on the remaining tree. This level of cooperation is extraordinary and exemplifies how Mainers really pitch in to help protect our state’s forests and landscapes.

Looking ahead to 2021, USDA indicated quite some time ago that they would be eliminating the federal EAB quarantine and focusing their efforts on developing management tactics. This deregulation will happen on January 14, 2021. DACF intends to maintain a state quarantine to slow the spread of EAB in Maine; however, federal deregulation will necessitate some changes to the state EAB quarantine rules. As we navigate the rule-making process in 2021, there will be an opportunity for the public to comment on any proposed rule changes. We will keep all nursery and other stakeholders informed.

Learn more about the EAB infestation in Maine

EAB montage

Signs of emerald ash borer infestation

Spotted Lanternfly - Spotted lanternfly is an invasive insect first found in the US in Pennsylvania in 2014.  Spotted lanternfly feeds on over 100 species of plants including economically important species such as apple, grape, hops and maple. The last couple of years have seen widespread movement of spotted lanternfly to new areas as SLF egg masses easily hitchhike on plants, cars, and other outdoor goods. This trend continued in 2020, and interceptions of multiple life stages, dead or alive, were detected in too many states to list. New, established populations of SLF were reported in Connecticut, Ohio and New York.

In September, the Horticulture Program was alerted by the New Hampshire Department of Agriculture, Markets and Food of a spotted lanternfly detection at a nursery in New Hampshire that had shipped potentially infested trees to landscapers in Maine. Horticulture inspectors located and inspected the trees planted in Maine and did not find any live spotted lanternfly, but remnants of hatched SLF egg masses were seen on several of the trees. We believe that some of the egg masses hatched before the plants arrived in Maine, but it is possible that egg masses observed on trees planted in Freeport and North Yarmouth may have hatched in Maine. The Horticulture Program plans on continuing to monitor these areas for spotted lanternfly in 2021.

Learn more about spotted lanternfly

Spotted Lanternfly

Life stages of the spotted lanternfly

Unsolicited Packages of Seeds - This summer, Mainers and people across the country reported receiving packages of seed from China and other countries that they had not purchased. These seeds had the potential to harm US agriculture and the environment by introducing new pests. Mainers turned in more than 300 packages of seeds to the USDA APHIS Plant Protection and Quarantine office in Hermon, Maine. It is believed that these packages are part of a “brushing” scam, whereby an online seller creates fake accounts and posts positive reviews in order to boost their ratings and sales on e-commerce sites. USDA collected the seeds and has only found a few noxious weed seeds. USDA has not found any evidence of malicious intent.

Learn more or report a package of unsolicited seeds

Ralstonia solanacearum race 3 biovar 2 – In late April, USDA APHIS Plant Protection and Quarantine (PPQ) notified the Horticulture Program that geraniums potentially infected with Ralstonia solanacearum race 3 biovar 2 (RsR3B2) were shipped to two Maine greenhouses. RsR3B2 is not known to occur in the United States and it is listed as a select agent on USDA’s bioterrorism list because it is a serious pest of potato and other solanaceous crops. The plants had been produced at a production facility in Guatemala and after arrival in the United States, were distributed to more than 650 facilities in 44 states. With the help of Maine’s USDA PPQ inspectors, both facilities in Maine were immediately inspected and no infected plant material was identified. In June, USDA declared the US free of RsR3B2.

More information on RsR3B2

Ralstonia solanacearum race 3 biovar 2

Geranium plant infected with Ralstonia solanacearum race 3 biovar 2

Japanese Stiltgrass – In September our partners in the Maine Natural Areas Program (MNAP) confirmed the presence of Japanese stiltgrass (Microstegium vimineum) in York County. This marks the first time that this invasive plant was officially confirmed in the state. Unfortunately, this find was at a nursery. MNAP and Horticulture program staff spent a day at the nursery, surveying and removing stiltgrass plants. Japanese stiltgrass is a shallow rooted annual that is easily hand pulled and sets seed late in the year. In addition to hand pulling, mowing or herbicides are viable control options. The infestation at the nursery appears to have been there for several years, but the population exploded this year as the nursery disturbed the soil when removing landscaping fabric. Japanese stiltgrass is a known hitch-hiker with nursery stock; it was not surprising that the first find in Maine would occur at a nursery and while we do not have any specific evidence that the nursery sold any infested nursery stock, they did provide a customer list and the Horticulture Program has contacted these customers and asked that they report any observations of Japanese stiltgrass. 

Looking ahead to 2021, we will continue to survey and work with the nursery to control their Japanese stiltgrass infestation. MNAP and the Horticulture Program also hope to be able to host a workshop at the nursery this summer for land managers, nurseries and others that may be on the front lines dealing with Japanese stiltgrass so they can see the plant and learn more about monitoring and control. 

Learn more about Japanese stiltgrass

Japanese stiltgrass

Japanese stiltgrass characteristics

The Horticulture Program works everyday to protect plant health in Maine. These are only some of the activities we were involved in 2020. Whether it was responding to one of the incidents above or to a shipment of twig wreaths that were potentially infested with an unknown boring beetle, helping a greenhouse identify and control impatiens downy mildew, answering numerous questions on unusual and common pests, conducting routine inspections at businesses selling plants and certifying numerous shipments of plants, seeds and forest products to be sent to other states and countries, 2020 was a busy year and we look forward to continuing our efforts to protect plant health in Maine into 2021 and beyond.

CAPS Nursery Survey Results

The Maine CAPS (Cooperative Agricultural Pest Survey) Program receives funding through a Cooperative Agreement with the USDA to survey for exotic and invasive plant pests. During the 2020 field season, the CAPS Program surveyed in and around 32 nurseries and garden centers in 13 counties for a variety of insect and plant disease pests that are not known to occur in Maine. Pheromone traps were set up at 15 nurseries to look for six exotic insects, such as pine tree lappet and the European cherry fruit fly, a new fruit tree pest recently discovered in New York. All traps were serviced every two weeks from early June to mid-September and the contents were screened in house for suspect target specimens. In addition, 25 nurseries received a thorough visual inspection by the DACF horticulture team, who looked at approximately 20,000 host trees for signs of exotic pests, such as Asian longhorned beetle, spotted lanternfly, apple proliferation and oak wilt. We are very pleased to report that none of the target specimens were discovered either visually or in our traps.  Trap contents that could be identified to species were recorded and results are being mailed to businesses that participated in the trapping survey. 

Full list of this year's CAPS Nursery Survey target pests and descriptions 

The Maine CAPS Program has surveyed in and around nurseries since 2015, and has reported negative data for 21 insect, 12 mollusk, and 7 pathogen exotic species. The DACF Horticulture Program thanks the continued cooperation of nurseries and plant sellers for allowing exotic pest surveys to occur on your properties.

Pests included in the CAPS Nursery Survey

Meetings and Events for the Horticulture Industry

In-person events may be off the table for the foreseeable future, but if you usually attend winter meetings (or even if you don't!) for pesticide credits or just to learn more about pests, plants, growing or managing your business, educational opportunities abound in the age of Zoom. Below are some online events that may be of interest.

Vegetable Seedling and Transplant Production in Greenhouses Webinar Series

Session 1: January 4, 2021 from 12:00 - 1:00 pm: Achieving Transplant Uniformity, Roberto Lopez, Associate Professor of Horticulture, Michigan State University

Session 2: January 5, 2021 from 12:00 - 1:00 pm: Managing Root-Zone in Plug Trays, Paul Fisher, Professor of Environmental Horticulture, University of Florida

Session 3*: January 6, 2021 from 12:00 - 1:00 pm: Using Organic Fertilizers for Vegetable Transplants, Neil Mattson, Associate Professor, School of Integrative Plant Science, Cornell University

Session 4*: January 7, 2021 from 12:00 - 1:00 pm: Identifying and Managing Pests of Vegetable Transplants, Leanne Pundt, Extension Educator, Department of Extension, University of Connecticut

Session 5*: January 8, 2021 from 12:00 - 1:00 pm: Identifying and Preventing Common Diseases in Herbs and Vegetable Seedlings in Greenhouses, Meg McGrath, Associate Professor, School of Integrative Plant Science, Cornell University

Credits: Sessions marked with a * are approved for a pesticide credit. See the website on details on how to qualify for credit.

Cost: $25 per session 


Questions and More Information: See the website or email

Tri State Greenhouse IPM Workshop "Virtual Reality" 

Session 1: Thursday, January 14th 1:00 – 3:30 pm: Bugging Out featuring Suzanne Wainwright-Evans, Buglady Consulting

Session 2: Thursday, January 21, 2021 1:00 – 3:30 pm: Disease Disaster featuring Margery Daughtrey, Cornell University

Credits: Up to 4 pesticide applicator recertification credits (2 per session). Must be in attendance and actively participate to receive credits.

Cost: $40.00 gets you signed up for BOTH sessions. Attend one or both!

REGISTER: You must pre-register by January 11, 2021!

What will you learn? The Tri-state Greenhouse IPM Program is a collaboration among growers and specialists from ME, NH and VT. This year’s virtual workshop program will be an intensive two-part online (Zoom) session focusing on insect (session 1) and disease (session 2) management. Through popular demand, featured speaker Suzanne Wainwright-Evans of Buglady Consulting will discuss the effective use of biocontrols. She has over 30 years of experience as a pest management consultant with some of the biggest greenhouses in the U.S. Featured speaker Margery Daughtrey from Cornell University is a top disease specialist and will deliver the hottest new strategies for avoiding disease disasters. Other speakers are your favorites from UVM, UNH and ME Dept. of Agriculture to cover new research and things to look out for in the tri-state region.

Who should attend? These workshops are for growers with greenhouses or high tunnels, extension specialists and professional pest managers. Growers of all experience levels and from any state are welcome to attend. Preregistration is required. Spots will be limited!  

Please note: If you are attending for credit and are registering as a group, please be sure to put the other attendees names and contact information when you add other attendees (after you register yourself).

Questions? contact Cheryl Frank Sullivan at

Green Spotlight Series from Coastal Maine Botanical Gardens and MELNA

January 14, 2021 from 4:00 - 5:00 pm: Water Management in Urban Landscapes, Jack Ahern

January 21, 2021 from 4:00 - 5:00 pm: Efficiency in Greenhouse Growing, Jeff Marstaller, Owner Cozy Acres Greenhouse in North Yarmouth

January 28, 2021 from 4:00 - 5:00 pm: Landscaping with Wild Edibles, Andy Brand, CMBG Curator of Living Collections

In partnership with the Maine Landscape and Nursery Association (MELNA), Coastal Maine Botanical Gardens (CMBG) presents the Green Spotlight Series featuring local and national researchers, instructors and field professionals from the green industry discussing topics valuable to peer professionals. The variety of topics on offer will appeal to a diverse range of landscape-related professionals from nursery and lawn-care specialists to arborists, landscapers, gardeners and landscape designers/architects. MELNA members are eligible for the CMBG member price and will earn recertification credits and several sessions will count toward the State of Maine's Pesticide License recertification. 

Creating a Sales Forecast for your Ag Business

When: January 14, 2021 and January 21, 2021 from 10:00 am - 12:00 pm

This two day short course will teach participants the importance of understanding the market to forecast their sales. The course is most beneficial for farmers with at least 2-3 years of experience selling an agricultural product, but wanting to explore a new idea for a product or market. This class will be small and will engage in a farmer - to - farmer discussion. It will help you gather information, make observations and analyze what you learned to create a forecast. Topics covered will include how to define your product, market area, understand your target market and potential customers. Consumption, partners, competitors and product pricing will also be discussed. A panel of New Hampshire growers from Sherman Farm, Center Conway, Stout Oak Farm, Brentwood, and Riverslea Farm, Epping will be featured. In addition to the farmer panel, Farm Credit East will cover how to develop a plan that creates revenue stability for your business utilizing the Whole Farm Revenue Program (WFRP). The class will be taught by UNH Extension staff, and will provide plenty of opportunities to share expertise and learn from one another.

REGISTER: This year’s course registration is free thanks to a grant from the USDA Risk Management Agency. Preregistration is required. Once registered, each individual will receive updates on how to access the meeting. Please pre-register by Sunday, January 10, 2021. Class size is limited.

For persons with disabilities, requiring special accommodations, please contact UNH Extension or 603-679-5616 prior to the event. Give us ample time, we will make any reasonable effort to arrange accommodations.

This material is based upon work supported by USDA/NIFA under Award Number 2018 -70027 - 28588

80th Annual Maine Agricultural Trades Show (ATS)

When: January 19 to 23, 2021

What will you learn? The five-day all-online ATS will feature a mixture of live- and pre-recorded presentations and forums on agricultural and forestry issues, sessions for ag producer groups, exhibitor showcases, and networking opportunities. The schedule will be a mix of day, evening, and weekend offerings. A digital library of content and information will remain fully accessible during and following the ATS for individuals who cannot join live sessions.

DACF will coordinate conference themes and presentations, directly responding to continuing feedback from the agricultural and forestry sectors. DACF staff are coordinating with interested producer groups to organize sessions. Also, pesticide credits and other annual credentials are included in this year's online ATS. Vendors and sponsors can also showcase their businesses online. The Department is looking forward to using this new format to share important information, interact with the broad agriculture and forestry communities, and celebrate Maine agriculture.

How to attend or participate: 2021 ATS schedule and attendee tips and exhibitor information

Questions? Email 

Can't Make a Scheduled Meeting? A Recorded Webinar Maybe for You!

Looking for an on-demand educational opportunity? Check out these previously recorded webinars and presentations.