Hort Notes 2020 Vol. 31:4

A monthly e-newsletter from UMass Extension for landscapers, arborists, and other Green Industry professionals, including monthly tips for home gardeners.

To read individual sections of the message, click on the section headings below to expand the content:

Lab Updates

Plant Diagnostic Laboratory

The UMass Plant Diagnostic Laboratory has reopened as of June 22 for plant disease, insect pest and invasive plant/weed samples. At this time, we can only accept mail-in samples, walk-in samples cannot be accepted. Please refer to our website for instructions on sample submission and to access the submission form: https://ag.umass.edu/services/plant-diagnostics-laboratory. Mail delivery services and staffing have been altered due to the pandemic, so please allow for some additional time for samples to arrive at the lab and undergo the diagnostic process. We look forward to resuming activities and diagnosing your plant problems!

UMass Soil & Plant Nutrient Testing Lab

The UMass Soil & Plant Nutrient Testing Lab will reopen on June 23, 2020, in order to analyze soil amples that were in process when the lab closed on March 16 and those that arrived after that date. Orders will be processed in the order they were received. Please be aware that they will not be accepting new samples for analysis until the backlog of orders is significantly reduced. Please do not send soil or plant samples for analysis until we are able to accept new orders. For updates and information about available services, please visit: https://ag.umass.edu/services/soil-plant-nutrient-testing-laboratory.

TickReport at the UMass Laboratory of Medical Zoology

The TickReport Risk Assessment & Passive Surveillance Program is open and tick samples can be submitted via https://www.tickreport.com. Please contact TickReport with tick-related questions and updates on the status of their service.

MA Pesticide License Info: Licenses, Study Manuals, and Exams

PESTICIDE LICENSE EXAMS - The MA Dept. of Agricultural Resources (MDAR) will begin holding pesticide exams during the week of June 15, 2020. These exams will be given in small numbers within the exam applicant's vehicle and will be scheduled in the order of cancellation with a focus on the Commercial Applicators License (Core) exam for the first few exams. Applicants will be contacted with the rescheduled date via email, which will include a set of detailed instructions. If an individual is not able to make the rescheduled date but would still like to take the exam, they will be placed at the end of the list for rescheduling. It is imperative that if an individual has opted to no longer take the test, they notify MDAR immediately. Due to the small group size for these exams, every spot counts towards getting through the backlog of cancelled exams as quickly as possible. Once all or most of the cancelled exams have been given, MDAR will open up the exam dates to allow for new exams to be offered.  MDAR has put out a request for bids relative to an online exam proctoring service for a long term solution.

PESTICIDE MANUALS – To order a copy to study prior to taking the exam, go to https://www.umass.edu/pested/study_materials/index.htm.

RECERTIFICATION CREDITS - UMass Extension's Pesticide Education Program is offering online workshops through June that offer recertification credits. For info on how to register for these, go to https://www.umass.edu/pested/recertification/current_workshops.htm.

For holders of Massachusetts pesticide licenses whose current three-year retraining or recertification cycle ends on 7/1/20, the MDAR Pesticide Program has extended the time permitted to earn credits to 12/31/20 as well as the number of computer-based or online credits that are acceptable for these specific individuals. This means that individuals with a three-year retraining cycle ending on 7/1/20 may obtain any portion or all of the needed training credits from online sources and have until 12/31/20 to do it. For more information, go to https://www.mass.gov/doc/pesticide-license-recertification-processes-and-related-impacts-from-covid-19/download 

TEMPORARY LICENSES - If your pesticide license has expired and you are unable to re-take the pesticide exam in 2020, the Mass. Dept. of Agricultural Resources will issue temporary pesticide licenses, without an exam, if certain criteria are met. For an individual with an expired license who wants to obtain a temporary Massachusetts Pesticide Applicator License, the license must have an expiration date of December 31, 2017 or after; the license was in good-standing when it expired; and the applicator has not had a pesticide violation within the past three (3) years; among other criteria. This significantly impacts pest control services; especially, seasonal businesses such as lawn care and mosquito and tick services. For more info on this update, go to https://www.mass.gov/guides/covid-19-resources-for-agriculture under Addressing COVID-19 Impacts, Bulletins and Guidance. You can find the specific bulletin at https://www.mass.gov/doc/mdar-bulletin-17-temporary-pesticide-license/download. These temporary licenses will expire on December 31, 2020. If you will want to be licensed in 2021, you will be required to take the pesticide exam.  

Hot Topics

Humidity and Water Management are Critical for Lawn Disease Prevention

Turf disease development is strongly influenced by environmental conditions within the turf canopy and the soil around the root zone. Temperature plays a role of course; for instance, red thread is typically seen in cooler weather, while brown patch appears in the heat of the summer. Free moisture and humidity also play a key role in disease development. Most fungi that cause plant diseases require free moisture to be available on plant surfaces for a certain amount of time in order for spore germination and infection to occur, and high humidity further promotes disease development. 

While there is nothing you can do about the weather, there are some things that lawn care professionals and homeowners can do to decrease humidity and free moisture in the turf microclimate and make conditions less hospitable to pathogenic fungi. Facilitate rapid drying of foliage after rain or irrigation by increasing air circulation and sun exposure on the turf. These factors are best considered prior to turf establishment but may be improved in existing sites by pruning or removing trees and shrubs. In warmer weather, dragging a hose over turf in the early morning can speed drying by knocking dew off the leaf blades. 

Watering is best done in the early morning, as increasing temperatures and sunlight will promote rapid drying of foliage as the day progresses. To maintain growth during summer, a general guideline for lawns in Southern New England is one inch of moisture input per week from either precipitation, supplemental irrigation, or a combination thereof. Watering deeply and infrequently is the best way to manage soil moisture in lawns. This practice also promotes the development of deep roots, an important characteristic that makes turf less susceptible to environmental stress and diseases. Excessively wet soil is not only conducive to numerous diseases, but the exclusion of oxygen in waterlogged soil also impairs proper root function, weakening turf and making it more susceptible to pathogens. 

Angela Madeiras, UMass Extension Diagnostic Technician Floriculture, Vegetable Crops, and Turf

Questions & Answers

Q.  What is causing this damage on my shrub?

A. The damage depicted here is caused by the larvae of the viburnum leaf beetle (Pyrrhalta viburni). The viburnum leaf beetle is in the family Chrysomelidae and is native to Europe, but was found in Massachusetts in 2004. Viburnum leaf beetle overwinters as eggs laid in capped pits on the newest growth of susceptible viburnum branches. Egg hatch occurs in late-April to early-May as temperatures warm and foliage becomes available. Monitor for larvae in mid-May (80-120 GDD’s). 

Recently, reports of viburnum leaf beetle larval feeding to UMass Extension have increased, likely because feeding damage is more apparent at this time. Feeding larvae were seen and reported on 5/31/20 in Southampton, MA and Pelham, MA. This beetle feeds exclusively on many different species of viburnum, which includes, but is not limited to, susceptible plants such as V. dentatum, V. nudum, V. opulus, V. propinquum, and V. rafinesquianum. Some viburnum have been observed to have varying levels of resistance to this insect, including but not limited to V. bodnantense, V. carlesii, V. davidii, V. plicatum, V. rhytidophyllum, V. setigerum, and V. sieboldii. More information about viburnum leaf beetle may be found at http://www.hort.cornell.edu/vlb/.

Soon, larvae will crawl to the soil to pupate, by mid-June. They will spend time as pupae in the soil, and emerge as adults in late June to early July, depending upon the location. Adults also cause feeding damage on the leaves of host plants, however instead of skeletonization of leaves, they create irregular, circular, or elliptical shaped holes. Adults can fly and move to new hosts. They will mate and females will begin to lay eggs which will overwinter to provide more beetles next season. Egg laying begins in July. Adults survive until they are killed by frost.

 

Q.  I found this hornet in Massachusetts. Should I be concerned that it is the Asian giant hornet? Should I report it?

A.  It would appear that this is the European hornet, Vespa crabro. This insect is known to Massachusetts, so finding it is not surprising, and it would not be reportable in MA. It's been in the USA since at least 1840 when it was first reported in New York.

However, it is one of the common look-a-likes for the Asian giant hornet, Vespa mandarinia. (Also referred to as the murder hornet - but I don't like that common name because I think it really evokes fear in a lot of people. Especially when, like other wasps and hornets, the Asian giant hornet usually leaves people alone if it does not feel threatened.) If you or anyone else is concerned that they have found the Asian giant hornet in Massachusetts, please report it here: https://massnrc.org/pests/pestFAQsheets/asiangianthornet.html

A very handy ID guide has been created by the USDA. Even though this guide was made for Texas, we have many of the same species in MA (with a few exceptions) and it is very helpful. However, if you're ever in doubt, report anything suspicious to the link above.

The USDA APHIS PPQ has also shared the following information:

• In December 2019, USDA confirmed the detection of a single Asian giant hornet (AGH) in Blaine, WA, and Washington State University identified a second AGH later that same month.
• Washington Department of Agriculture (WSDA) is currently surveying the state for this pest. Should WSDA locate any AGH nests, they will respond quickly to eradicate them.
• Although there are a number of unconfirmed AGH sightings from the public, neither USDA nor WSDA has any evidence that AGH populations are established in Washington or anywhere else in the United States. These unconfirmed sightings may be lookalike hornet species that are known to occur in the United States.
• Asian giant hornet does not attack people unless it feels threatened. They are known to attack and kill other bees in the late summer when developing males and future queens need extra protein to complete their life cycle. They do not attack and kill bees at other times.
• More information about the Asian giant hornet may also be found here: https://www.aphis.usda.gov/planthealth/agh 
   

Q.  I found this scale on elms in our town. I believe it is the European elm scale. Is this something I should report?

A.  Those are definitely European elm scales (Gossyparia spuria)! They are common to the area, so you do not have to worry about them being reportable.

They can, like other soft scales (technically they are a felt scale), create honeydew and sooty mold. Eventually, if the population builds enough, they may cause premature leaf drop, yellowing of foliage, and possibly dieback of branches.

All that said, beneficial insects can usually manage this scale. The scales feed on native and introduced elms, but Asiatic elms may be less susceptible. Yellow colored crawlers, or the mobile stage of this insect, may be seen on the undersides of leaves if you flip them over and examine the leaf-vein with a hand lens (they are tiny). You can look for these any time between May and the fall. 

If the population size isn't too high and the trees generally look like they are doing well, you could wait until next spring (early April) to apply a dormant oil. This should be sprayed on the bark of the trunk and branches, as that is where the immatures overwinter.

 

Q.  I thought you said there weren’t supposed to be any gypsy moths this year? Well, how do you explain this?

A.  Thanks to the gypsy moth caterpillar killing fungus, Entomophaga maimaiga, the recent outbreak of gypsy moth in Massachusetts has come to an end! Most locations in Massachusetts will not see damaging or even noticeable populations of this insect in 2020. However, that does not mean the occasional caterpillar won’t be seen in certain areas of the state.

Gypsy moth has been in Massachusetts since the 1860's. This invasive insect from Europe often goes unnoticed, thanks to population regulation provided by the entomopathogenic fungus, E. maimaiga, as well as a NPV virus specific to gypsy moth caterpillars (and to a lesser extent many other organisms, including other insects, small mammals, and birds who feed on gypsy moth). However, if environmental conditions do not favor the life cycle of the fungus, outbreaks of gypsy moth caterpillars are possible (such as most recently from 2015-2018, with a peak in the gypsy moth population in 2017 in Massachusetts).

A young gypsy moth caterpillar was seen feeding on willow in Chesterfield, MA on 6/3/20, despite the relative lack of overwintering gypsy moth egg masses in the area. The impact of gypsy moth in this particular hilltown in Hampshire County has been negligible. Chesterfield was lucky to escape the outbreak populations from 2015-2018. Why is it still possible for gypsy moth caterpillars to be found? Well, the fungus and the virus responsible for killing gypsy moth caterpillars (and thus regulating populations in most years) do not kill 100% of the insects. There will always be a few gypsy moth caterpillars, pupae, adults, and eggs that survive in Massachusetts. The key part is, in most locations in MA in 2020, populations will be so low that feeding damage caused by the caterpillars will be slight to non-detectable.

Missing gypsy moth already? Check out Episode 1 of InsectXaminer to reminisce about the 2015-2018 outbreak of this insect: https://ag.umass.edu/landscape/education-events/insectxaminer

 

Q.   I found these caterpillars and their webbing all over a European spindle tree (Euonymus europaeus). What are they?

A.  Yponomeuta cagnagella or the euonymus caterpillar is of European origin and widespread in distribution throughout Europe. It was first reported in North America in Ontario in 1967. Euonymus caterpillars (larvae) feed in groups and envelop the foliage of the host plant in webs as they feed. Hosts include: Euonymus europaeus (tree form), E. kiautschovicus, E. alatus, and E. japonicus. Mature caterpillars are just under an inch in length, creamy yellow-gray in color with black spots and a black head capsule. By late June, these larvae pupate in white, oval-shaped cocoons which are typically oriented together vertically either on host plants or non-hosts in the area. Cocoons can be found in cracks and crevices, or webbed together leaves. The adult moth emerges in late June in most locations. The adult female secretes a gummy substance over her eggs which will harden, making them even more difficult to see. Eggs hatch by mid-August, at which time the tiny larvae prepare to overwinter beneath their eggshell-like covering. These larvae are inactive until the following year, when caterpillars group together to feed on newly emerging leaves, creating a mess of webs as they feed. There is one generation per year. Plants may be partially or entirely defoliated. Management of young, actively feeding caterpillars with Bacillus thuringiensis is possible if deemed necessary; however, many species of Euonymus are considered invasive themselves.

Want to see euonymus caterpillars in action?! I bet you’ve never seen so many of these caterpillars in one place before! Check out Episode 3 of InsectXaminer: https://ag.umass.edu/landscape/education-events/insectxaminer .

Tawny Simisky, Extension Entomologist, UMass Extension Landscape, Nursery, & Urban Forestry Program

Trouble Maker of the Month

Yellow Nutsedge Management in Turf and Landscape

Garden Clippings Tips of the Month

June is the time to:

• New to gardening? Check out the weekly articles in our new series, Food Gardening in Massachusetts 2020. With the uncertainties around the Coronavirus (COVID-19) and the economy, growing your own food is appealing as a way to help alleviate food insecurity, do something fun that is compatible with social distancing, and produce healthy and nutritious food! UMass Extension authors Frank Mangan and Heriberto Godoy-Hernandez offer this series of weekly articles which provide research-based information in English and Spanish on how to grow your own vegetables and herbs in Massachusetts.
• Pay attention to watering needs. Install a rain gauge so that you know exactly how much precipitation has fallen.  
  • For lawns, water deeply and infrequently to encourage deep rooting. Water in the early morning when the grass would naturally be wet with dew.  Most lawns require about an inch of water each week. Try not to water midday when evaporation is highest.
  • For flower and vegetable gardens, install drip irrigation. Drip irrigation is easy to install, conserves water, and does not wet foliage, potentially reducing disease.
  • For newly planted trees, shrubs and flowers, water frequently until they become established. After establishment, water deeply and less frequently to encourage deep rooting.
  • For containers, consider setting up a drip system with tubing and a timer to save yourself some time.
• Support tomato plants shortly after planting. Try using a trellis for vigorous indeterminate tomatoes or the basket weave for determinate tomatoes. For cherries and paste varieties, make big cages 22-24 inches in diameter and 4 feet tall using concrete reinforcement wire. Don’t throw out the old cone shaped tomato cages – they are perfect for peppers and eggplant. Prune tomatoes by removing the shoots that form in the leaf axils on large fruiting varieties.
• Keep pinching perennials like chrysanthemums and asters. Pinching helps produce nicely mounded plants.   
• June is the month to raise mowing height. Raising the mower to a height of 3-4” inches during the hottest, driest months can help reduce stress. Keep mower blades sharp, return clippings to the lawn and don’t mow when the grass is wet.
• Use mulches in the vegetable garden. Black plastic mulch works great for heat loving crops like tomatoes, peppers, cucumbers, squash and melons. For crops that like it cooler, use natural mulches such as straw. Mulches will reduce weeds and conserve soil moisture.  
• Take the time to monitor plants for pests and damage. Timely identification will allow intervention before pests get out of hand. When monitoring, look carefully over the entire plant from the base to the top, also looking at the undersides of leaves. A magnifying glass can help make out anything the naked eye can’t.
• Fruit trees like apple and pear often experience June drop which can be alarming. June drop is typically a result of poor pollination or a tree self-regulating fruit load. Peaches and nectarines will require thinning to manage crop load. Thin peach and nectarine fruits to a distance of 4-6 inches, remove fruit with signs of insect or disease damage, and keep fruit that are healthy and on the top side of twigs for better color development.  
• Stay vigilant with weeding!  Weed on the hottest driest days for quick killing of weeds. Use tools that minimally disturb the soil so as not to bring a new crop of weed seeds to the surface.   
• Avoid line trimmer damage to trees by eliminating turf and creating mulch rings. Mulch rings also promote tree health by reducing competition for water and nutrients. Spread mulch 2-4 inches deep, making sure no mulch is touching the trunk of the tree. 

Russ Norton, Horticulturist, Cape Cod Cooperative Extension

Can Community Forests in the Northeast U.S. Keep Pace with a Changing Climate?

At the end of winter, several degrees of warming temperatures might not sound too bad. But, for forest trees in native ecosystems and urban neighborhoods, climate change is likely to have a variety of effects on tree health. Since our temperature records began in 1880, average global temperatures have risen approximately 0.8°C (1.5°F) and in the coming years, ongoing greenhouse gas emissions are predicted to exacerbate this change further. Projections for the 21st century depend on greenhouse gas emission levels, but models anticipate that we could see another 0.6°C (1°F) in the next 20 years and up to 4.4°C (8°F) by the end of the century. Plants have already been responding to rising temperatures by greening up earlier in the spring. In the northern hemisphere, plants are also slowly shifting their distribution northward and upward in elevation in response to warming weather trends.  

Trees are unable to transplant themselves and readily move north to cooler climates; thus, they may be increasingly stressed by rising temperatures at the warm range margins of their climate tolerance or provenance. As a consequence, increasing rates of forest tree mortality have been observed globally. Tree seedlings are having a harder time germinating and establishing at warm range margins, but an easier time at cool range margins. Over time, this creates a shift in forest tree range. For example, surveys of change in forest composition in Vermont’s Green Mountains between 1964-2004 showed an upward range expansion of northern hardwoods and an accompanying range contraction of higher elevation boreal forest species. 

Current climate change projections suggest that plants will need to annually migrate 3,000-5,000 meters faster than their observed natural ability of less than 500 meters. When compared to short-lived plant species, trees will have an additional challenge, as it may take several generations, ranging from centuries to a millennium, for a tree population to become evolutionarily adapted to new climate conditions. This implies that without human assistance, most tree communities may be unable to keep up with the forthcoming warming temperatures.

Warming conditions will also affect the health of urban trees. Urban forest managers and commercial arborists may be able to provide some relief to existing tree populations by encouraging best management practices that help alleviate some of the environmental stresses associated with warmer and drier climate conditions. For instance, strategically applying mulch can protect a tree from soil compaction, injury to its roots and stem, and soil moisture loss during periods of drought. Optimizing watering schedules may also aide in a tree’s ability to adapt to a warmer climate by easing the stress of longer, warmer growing seasons. Forgoing fertilization may be beneficial to trees with no demonstrated nutrient deficiencies, to avoid pushing unnecessary growth instead of concentrating their limited resources on surviving a potentially difficult growing season. 

Despite the many uncertainties surrounding future climate conditions, researchers have made predictions for the potential changes to the structure of our forests. Projections suggest that many ecologically and economically important species, such as sugar maple (Acer saccharum) and balsam fir (Abies balsamea), are likely to lose a significant amount of suitable habitat in the Northeast over the next 100 years. Habitat for northern hardwood (maple-beech-birch) and northern mixed (aspen-birch, white-red-jack pine) forests in the region is likely to become better suited to oak-hickory hardwood and oak-pine mixed forests; habitat for some oak species may increase as much as three times. One study comparing low and high emissions scenarios contends that under a low emissions scenario, conditions will favor maple-beech-birch forests, while oak-hickory forests will be favored under a high emissions scenario.

In the urban forest, experts recommend planting resilient species such as Kentucky coffee-tree (Gymnocladus dioicus), London plane-tree (Platanus x acerifolia), hackberry (Celtis occidentalis), honey-locust (Gleditsia triacanthos), swamp white oak (Quercus bicolor), and Freeman maple (Acer x freemanii), all of which have been successfully installed for many years in the Northeast by Tree Wardens, arborists, and urban foresters. It is also recommended to incorporate a diverse array of species that are not only indigenous to more southerly climates, but are tolerant of urban growing conditions, such as bald-cypress (Taxodium distichum), sweet-gum (Liquidambar styraciflua), and several common southern oak trees, like turkey oak (Quercus laevis) and willow oak (Quercus phellos). Some of the tree species common to the region predicted to lose ground as a result of climate change include shagbark hickory (Carya ovata) and American basswood (Tilia americana L.). Urban foresters and arborists should think twice before selecting and planting these types of trees.  

"Assisting" the migration of these species further north may improve the long-term viability of tree species under climate change, with the potential to prevent extinction, minimize economic loss, and sustain ecosystem services. Species most likely to persist will be the ones we choose to plant outside of their historic range. However, there are various challenges to this strategy. Having a lack of specific implementation instructions, uncertainties about future climate conditions, existing policies, and the risks associated with moving plants outside their current ranges can all hinder efforts to execute assisted migration.

Extreme caution must be used when introducing plants to areas outside of their current ranges; the greater the distance from a species’ range, whether it be geographic or climatic, the greater the financial responsibility and ecological risk, as well as a possible loss in productivity, decrease in fitness, or mortality. Additionally, although maintaining a high level of diversity in an urban forest is encouraged, as it provides some long-term insurance against the uncertainty in species’ reactions to climate change, extremely high levels of diversity may cause suitable native trees to be outcompeted. If an introduced species proves to be invasive in its new habitat, it can pile on to the stress of an urban forest caused by climate change. The invasive plant atlas of the U.S. (www.invasiveplantatlas.org) lists over 200 tree species identified as invasive somewhere in the U.S. Almost all of these species are of international origin, making the introduction of new trees from exotic locales a risky proposition for native New England ecosystems.  

Planting these "exotic" species not only increases the likelihood of introducing a novel invasive plant, international live plant imports are also the primary source of forest pests. An estimated 12% of live plant imports are contaminated by some form of forest insect, mite or pathogen. Moreover, warmer temperatures with climate change can sustain higher populations and diversity of forest pests, which tend to be less cold tolerant. This combination of increasing pest introductions and improving climate conditions for pests means that we can expect more outbreaks of both known and unknown pests and pathogens ahead. Pest management protocols for urban trees, including vigilant monitoring, confirmation of diagnosis, and appropriate remedial actions should be implemented where appropriate.  

In addition to shifting plant and pest distributions, climate change is also lengthening the growing season. For example, based on historical herbarium records, flowering time in Massachusetts advanced by an average of 8 days between 1900-2000. While it is nice to see those spring blooms a little earlier, one consequence is that species are being increasingly damaged by frost. Leafing out during an early warming leaves buds and leaves exposed to normal spring cold snaps. Additionally, early warming may impact the essential relationship between trees and animals regarding their synchronized timing of pollination and seed dispersal. The longer growing seasons and higher atmospheric CO2 concentrations forecasted may work in favor of increasing tree productivity, but changes in suitable habitat, pests, and disease, in adjunct with increased drought, air pollution, nitrogen deposition, and acid rain, may result in an overall decrease in tree productivity.

To understand future forest change, ongoing and thorough inventorying, monitoring, and analysis is necessary. Urban forests provide a myriad of ecosystem services, and maintaining their resilience under warming climate conditions to preserve these benefits will require significant management efforts. Preserving tree species towards the southern edges of their range means mitigating drought and pest stress. Meanwhile, assisting migration by selecting tree species that increase the diversity of more southerly North American trees is one important step in helping to promote healthy urban forests into the future.  

 

 

 

 

 

 

Literature Cited

• Bell, A. 2013. Trees for 2050 [database]. Chicago Botanic Garden. 
• Beckage, B., B. Osborne, D.G. Gavin, C. Pucko, T. Siccama, and T. Perkins. 2008. A rapid upward shift of a forest ecotone during 40 years of warming in the Green Mountains of Vermont. Proceedings of the National Academy of Sciences 105(11): 4197-4202.
• IPCC, 2013: Summary for Policymakers. In: Climate Change 2013: The physical science basis. Contribution of working group I to the fifth assessment report of the intergovernmental panel on climate change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S. K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
• Iverson, L. R., A. M. Prasad, S. N. Matthews, and M. Peters. 2008. Estimating potential habitat for 134 eastern US tree species under six climate scenarios. Forest Ecology and Management. 254:390-406. 
• Liebhold, A. M., E.G. Brockerhoff, L.J. Garrett, and K.O. Britton. 2012. Live plant imports: the major pathway for forest insect and pathogen invasions of the US. Frontiers in Ecology and the Environment 10(3):135-143.
• Miller-Rushing, A. J., & R.B. Primack. 2008. Global warming and flowering times in Thoreau's Concord: a community perspective. Ecology 89(2):332-341.
• Prasad, A. M., L. R. Iverson., S. Matthews., M. Peters. 2007-ongoing. A climate change atlas for 134 forest tree species of the eastern United States [database]. Northern Research Station, USDA Forest Service, Delaware, OH.
• Rustad, L., J. Campbell, J.S. Dukes, T. Huntington, K.F. Lambert, J. Mohan, N. Rodenhouse.  2012.  Changing climate, changing forests: The impacts of climate change on forests of the northeastern United States and eastern Canada. Gen. Tech. Rep. NRS-99. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 48 pp. 
• Van der Veken, S., M. Hermy, M. Vellend, A. Knapen and K. Verheyen. 2008. Garden plants get a head start on climate change. Frontiers in Ecology and the Environment 6(4):212-216.
• Williams, M.I., and R.K. Dumroese. 2013. Preparing for Climate Change: Forestry and 
• Assisted Migration. J. For. 111(4):287-297.
• Woodall, C.W., D.J. Nowak, G.C. Liknes, and J.A. Westfall. 2010. Assessing the potential for urban trees to facilitate forest tree migration in the eastern United States. Forest Ecology and Management. 254:1447-1454. 
• Woodall, C.W., C.M. Oswalt, J.A. Westfall, C.H. Perry, M.D. Nelson, and A.O. Finley. 2009. An indicator of tree migration in forests of the eastern United States. 257: 1434-1444. 
   

Upcoming Events

Operations at the University of Massachusetts Amherst have been significantly reduced in response to the COVID-19 pandemic and all in-person UMass Extension events scheduled through June have been canceled or postponed. Our professional staff are working remotely to maintain and expand our remote educational services.

Invasive Insect Webinars

Join UMass Extension’s Landscape, Nursery, and Urban Forestry Program and UMass Extension’s Fruit Program for an exciting FREE series of seven webinars focusing on the impact, monitoring, and management of invasive insects in Massachusetts and the nation! Find the registration links in our Events listing at https://ag.umass.edu/landscape/upcoming-events. One pesticide contact hour for categories 29, 35, 36 and Applicators (Core) License is available for each webinar in this series. Webinars are held live noon to 1:00 pm; recordings of the webinars will be archived for later viewing at https://ag.umass.edu/landscape/education-events/invasive-insect-webinars.

• June 16 - The Invasive Pest Brown Marmorated Stink Bug in Massachusetts: Biology, Monitoring, and Management
• June 23 - Progress towards Controlling the Emerald Ash Borer with Biological Control
• June 30 - Invasive Insects of Trees & Shrubs in Massachusetts: 2020 Updates 

Tune in to a TickTalk with TickReport Webinars

This is a FREE live webinar series by Dr. Stephen Rich, Director of the UMass Laboratory of Medical Zoology held noon to 1:00 pm on the 2nd Wednesday of the month. Co-sponsored by UMass Extension and the UMass Laboratory of Medical Zoology.

• June 10 - Tick Management and Control
  Dr. Stephen Rich, Professor of Microbiology and Director of the UMass Laboratory of Medical Zoology, and Dr. Kirby Stafford, Chief Scientist at the Connecticut Agricultural Experiment Station and CT State Entomologist, will discuss tick management strategies applicable to landscapes in the Northeast.  Dr. Stafford is a medical-veterinary entomologist whose research expertise is on the ecology and control of ticks, especially the black-legged or deer tick (Ixodes scapularis) that transmits several pathogens, including those that cause Lyme disease, human babesiosis, and human ehrlichiosis. Register at https://ag.umass.edu/landscape/education-events/webinars
• July-Dec: noon to 1:00 pm on the 2nd Wednesday of the month, topics TBA.

Did you miss the last webinar? Watch past topics of archived webinars at https://ag.umass.edu/landscape/education-events/ticktalk-with-tickreport-webinars. 

InsectXaminer! 

This new short video series hopes to increase the visibility of the beautiful world of insects, even those we consider to be pests in our managed landscapes. Check out Episode 3 on Euonymus Caterpillar (Yponomeuta cagnagella), available at: https://ag.umass.edu/landscape/education-events/insectxaminer 

Registration for the following events has been temporarily suspended while we await further guidance regarding public gatherings from public health officials and the University of Massachusetts. 

• 7/8 - State Regulations Pertaining to Invasive Plant Management (part A2: Invasive Plant Management Certification Program)
• 8/5 - The Invasive Plant Issue and Invasive Plant Identification (part A3: Invasive Plant Management Certification Program)
• 8/19 - Developing an Invasive Plant Management Program (part B: Invasive Plant Management Certification Program)
• 9/9 -  Ornamental Tree & Shrub ID and Insect Walk
• 10/26-12/10 - Green School

For more details for any of these events, go to the UMass Extension Landscape, Nursery, and Urban Forestry Program Upcoming Events Page. 

Pesticide Exam Preparation and Recertification Courses

Since it is uncertain when we will be able to offer these workshops in a live setting, these workshops have been converted to a remote/online format. Contact Natalia Clifton at nclifton@umass.edu directly before you register for these workshops. For more details, go to https://www.umass.edu/pested/training_workshops.

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Additional Resources

For detailed reports on growing conditions and pest activity – Check out the Landscape Message

For commercial growers of greenhouse crops and flowers - Check out the New England Greenhouse Update website

For professional turf managers - Check out our Turf Management Updates

For home gardeners and garden retailers - Check out our home lawn and garden resources. UMass Extension also has a Twitter feed that provides timely, daily gardening tips, sunrise and sunset times to home gardeners at twitter.com/UMassGardenClip

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Food Gardening in Massachusetts 2020

With the uncertainties around the Coronavirus (COVID-19) and the economy, growing your own food is appealing as a way to help alleviate food insecurity, do something fun that is compatible with social distancing, and produce healthy and nutritious food! To become a successful gardener is not complicated; for the most part, the needed skills can be easily mastered. Join us for this series of weekly articles which with provide research-based information on how to grow your own vegetables and herbs in Massachusetts.

Some of the content has been adapted from the New England Vegetable Management Guide, a collaborative effort by members of the Extension Vegetable Programs of the New England states. These articles are written by Frank Mangan, Extension Professor of Vegetable Crops at the UMass Stockbridge School of Agriculture, and his Ph.D. student, Heriberto Godoy Hernandez, and are available in both English and Spanish. Additional expertise on specific topics is provided by UMass Extension Specialists.

Growing Your Own Food with Franco and Beto (Columna de Franco y Beto sobre el cultivo de sus propias hortalizas y hierbas aromáticas en Massachusetts) is available here: https://ag.umass.edu/resources/home-lawn-garden/food-gardening-in-massachusetts-2020

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Diagnostic Services

Current Massachusetts and University policy have the effect of temporarily suspending most of the on-campus services that we provide, including but not limited to:

• Soil and Plant Nutrient Testing Lab
• Plant Disease Diagnostics Lab
• Weed, Insect, Turfgrass, and Invasive Plant Identification

These services are currently suspended. Until further notice, please do not send or deliver samples to the campus, as we cannot process them.

A UMass Laboratory Diagnoses Landscape and Turf Problems - When normal services resume, the UMass Extension Plant Diagnostic Lab is available to serve commercial landscape contractors, turf managers, arborists, nurseries and other green industry professionals. It provides woody plant and turf disease analysis, woody plant and turf insect identification, turfgrass identification, weed identification, and offers a report of pest management strategies that are research based, economically sound and environmentally appropriate for the situation. Accurate diagnosis for a turf or landscape problem can often eliminate or reduce the need for pesticide use. For sampling procedures, detailed submission instructions and a list of fees, go to Plant Diagnostics Laboratory. No samples are being accepted at this time.

Soil and Plant Nutrient Testing - When normal services resume, the University of Massachusetts Soil and Plant Nutrient Testing Laboratory is located on the campus of The University of Massachusetts at Amherst. Testing services are available to all. The function of the Soil and Plant Nutrient Testing Laboratory is to provide test results and recommendations that lead to the wise and economical use of soils and soil amendments. For complete information, visit the UMass Soil and Plant Nutrient Testing Laboratory web site. Alternatively, call the lab at (413) 545-2311. No samples are being accepted at this time.

TickReport Update - Due to unprecedented circumstances of the global pandemic, the University of Massachusetts has mandated work furloughs for all university staff. Unfortunately this order comes at the annual peak of tick activity, and hence TickReport testing will not be available during the furlough. Effective at 11:59PM on 3-June-2020, until 12:01AM on 19-June-2020, TickReport will not be accepting new orders. For a full statement from TickReport, please visit: https://www.tickreport.com . Please contact TickReport with further questions and updates on the status of their service.