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Hort Notes 2018 Vol. 29:11

November 1

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

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

Hot Topics

Thank your clients with a 2019 UMass Garden Calendar!

Cost: $14, with a bulk rate available for quantities of 10 or more.

Gardening is enjoyed by so many people — it can ease stress, keep you limber, and even improve your mood! To help keep your plants healthy, productive, and beautiful, the 2019 UMass Garden Calendar offers helpful guidelines, daily tips, and an inspiring garden image each month!

For many years, UMass Extension has worked with the citizens of Massachusetts to help them make sound choices about growing, planting and maintaining plants in their landscapes, including vegetables, backyard fruits, and ornamental plants. Our 2019 calendar continues UMass Extension’s tradition of providing gardeners with useful information. This year’s calendar features the use of tomography to identify internal decay in mature trees that do not yet show any visible symptoms of damage, making it difficult to assess their potential risk in urban and suburban settings.

Each Month Features

  • An inspiring garden image
  • Daily gardening tips for Northeast growing conditions
  • Daily sunrise and sunset times
  • Phases of the moon
  • Plenty of room for notes
  • Low gloss paper for easy writing

ORDER ONLINE at www.umassgardencalendar.org

 

Questions & Answers

Q. What in the world is this weird stuff growing on my mulch?

There are a number of organisms that may be found growing on wood chips and mulch, most often after a period of wet weather, any time from early spring through late fall. Most are fungi and they are saprophytes, meaning that they eat dead and decaying plant matter. Slime molds are Protozoans that feed on bacteria and fungi. None of these things are pathogenic to plants, and few are likely to be poisonous to people or pets. All of these organisms are ephemeral and controlled through cultural practices. Fungicides are ineffective and typically unnecessary. 

Artillery Fungus - Sphaerobolus stellatus
The fruiting bodies of the artillery fungus are small, semi-spherical, golden to tan colored structures. Eventually these structures open to reveal tiny, dark, rounded packets of spores called peridioles. Cool (50-68°F), wet weather is conducive to their production. Peridioles are forcibly ejected from the body of the fungus and can travel several yards. They stick rather persistently to homes, cars, fences, and anything else they land on. Artillery fungus can be managed by raking mulch to break up fruiting bodies and facilitate drying of the mulch. Bark mulch is less hospitable to artillery fungus than wood chips: a mulch containing >85% bark is recommended. Of course, an inorganic mulch such as stone or plastic could be used as well. Artillery fungus belongs to the same fungal family as earth stars.

Birds Nest Fungi - Crucibulum, Cyathus, Mycocalia, Nidula, and Nidularia species
These cute little fungi produce cup-shaped fruiting bodies that resemble birds’ nests. The “eggs” inside the nests are the peridioles, which may be black to dark gray, tan, or white. These are not forcibly ejected as they are in artillery fungus, but are moved by splashing water. When peridioles dry, they release fungal spores that are dispersed by wind. Management is similar to that of artillery fungus.


Earth Stars - order Geastraceae
In damp weather, the “petals” of the earth star peel back to expose the spore-filled fruiting body in the center. Fruiting bodies release copious fine spores, which are dispersed by wind. Species vary in size: larger ones can be removed manually. Management is similar to that of artillery fungus. There is some anecdotal evidence from dog owners that eating some earth star species can cause gastrointestinal distress, but none are considered deadly. Not to be confused with the houseplant that goes by the same name. 

Mushrooms - numerous species
There are many species of mushroom that may pop up in your garden beds or lawn. Some mushrooms may actually be growing not out of mulch but from decaying tree roots well below the soil surface. Some species form circles and are known as fairy rings. Fairy rings can persist for some years, but the period of mushroom production is brief and typically occurs only once per year for each species. If mushrooms are troublesome, they may be removed manually. 

Slime Molds - numerous species 
Slime molds are not fungi but belong to the group of single celled organisms called Protists. They come in a striking variety of colors and shapes. These organisms spend the majority of their lives as single cells, but when conditions are right, cells begin to aggregate and form visible structures. The purpose of this behavior is reproduction via the generation of spores. Slime molds can also appear on lawns and may cause grass to turn yellow because they block sunlight, impeding photosynthesis. They will dry up and disappear after a few days, and the grass will recover. Raking mulch or grass can help speed this process by breaking up the slime mold and drying out the surface of what it’s growing on. 

Birds nest fungus (Angela Madeiras) Birds nest fungus striatus (Angela Madeiras) Earth Stars (Angela Madeiras) Slime Mold (Robert Wick)

 

 

 

 

 

 

Angela Madeiras, UMass Extension Plant Pathologist

Trouble Maker of the Month

Boxwood blight

Boxwood blight, caused by Calonectria pseudonaviculata, on boxwood (Buxus sempervirens, B. sempervirens ‘Suffruticosa’ and B. sempervirens ‘Vardar Valley’). Infected shrubs range in age from 3-years-old to nearly 40-years-old at several sites in eastern Massachusetts, coastal Rhode Island, and northwestern and southern Connecticut. At some of the sites, the outbreaks developed on boxwoods transplanted earlier this year, which is the most common pattern of disease development. However, at other sites, it’s suspected that latent infections from previous years went unnoticed until major symptoms developed this season. At one site, pruning shears harboring the pathogen are suspected to have introduced the disease.

The abundant rainfall from mid-July through October this year has led to high levels of spore production and dispersal. There have been reports of large landscapes with hundreds of infected boxwoods. Calonectria is able to attack all above-ground plant parts, but does not infect the roots. It can, however, produce a resting structure that allows it to survive and overwinter in dead plant parts (e.g. leaves and stems) that both remain in the canopy and have fallen to the ground. Spores are then produced from these resting structures and are blown or splashed onto nearby, healthy plants. In many cases, it’s recommended to remove infected plants and all nearby organic matter that could be harboring inoculum. For mature plants where intervention is desired, extensive pruning of blighted material and the use of a combination contact and systemic fungicide is recommended.

For images of boxwood blight, go to the Massachusetts Introduced Pests Outreach Project page at https://massnrc.org/pests/pestFAQsheets/boxwoodblight.html

For our fact sheet Emerging and Established Diseases of Boxwood, go to https://ag.umass.edu/landscape/news/emerging-established-diseases-of-boxwood.

Nick Brazee, UMass Extension Plant Pathologist

Plant of the Month

Dendranthema x grandiflorum 'Sheffield', Sheffield Pink Chrysanthemum

Sheffield Pink Chrysanthemum is a prolific fall blooming plant with beautiful apricot-pink fragrant flowers with golden yellow centers. It is hardy to USDA zones 5 to 9 with a long bloom period. Sheffield pink chrysanthemum blooms in fall through late fall and the flowers are attractive to butterflies and other pollinators.

This clump forming chrysanthemum grows 2-3 feet tall and spreads to 2-3 feet wide. Leaves are light to medium green, lobed and up to 2 inches long. It thrives best in full sun and in moist, well-drained soils rich in organic matter. It can tolerate light shade, especially in the afternoon. To keep plants compact and to encourage bushy vegetative growth, stems can be pinched in mid-June to early July. Pinching also helps to delay flowering. Divide plants every 2 to 3 years in spring or fall to prevent plants from becoming old and woody.

'Sheffield Pink' can be used in mass plantings, for large-scale edging, or in borders. It also adapts well for growing in tubs and mixed containers, and is excellent for cutting. 

Problem pests include: Aphids, thrips and spider mites, which can cause significant damage. Other potential problems include Botrytis, leaf spots, powdery mildew, stem and root rots. 

'Sheffield Pink' Chrysanthemum 'Sheffield Pink' Chrysanthemum 'Sheffield Pink' Chrysanthemum

 

 

 

 

 

Geoffrey Njue, UMass Extension Sustainable Landscapes Specialist

Upcoming Events

2018 Fall Wrap-Up

November 27, 2018 - 8:30 am to 4:00 pm
Location: Hadley Farms Meeting House, Hadley MA

Join our UMass Extension Specialists for a look at the challenges and problems of the 2018 season. Topics include woody plant insects and diseases, landscape weeds, how to deal with weedy grass failures – factors that may contribute to poor control and/or summer surge, turf insects, how to distinguish whether decline or damage to turf is due to pests or abiotic stressors, and BMPs to maximize turf stress tolerance. Pesticide contact hours and association credits pending.


Spotted Lanternfly Preparedness Conference

February 7, 2019 - 8:30 am to 3:30 pm
Location: Doubletree Hotel, Milford MA

The spotted lanternfly (Lycorma delicatula) was first detected in the United States in Pennsylvania in 2014. This non-native, invasive insect has since had a large impact on agricultural and ornamental crops and the quality of life of many Pennsylvania residents. While this insect is associated with the invasive tree of heaven (Ailanthus altissima), it has been reported from 70+ species of host plants, including apple, plum, peach, grape, and many native and ornamental trees and shrubs. This insect is unfortunately on the move, having been detected in additional states including Delaware, New York, Virginia, New Jersey, Connecticut, and Maryland.

What can we do in Massachusetts to prepare for this insect? Knowledge is power. This conference will provide the latest research and information about the identification, life cycle, impact, monitoring, and Integrated Pest Management options that are known for this insect. Landscapers, arborists, tree wardens, foresters, nursery operators, lawn care professionals, grounds managers, and tree fruit and small fruit growers are encouraged to attend. Join UMass Extension in learning more about the spotted lanternfly!  6 pesticide contact hours for categories 25, 27, 29, 35, 36, and Applicators License.

 

For complete information, including the schedule and registration information, go to http://ag.umass.edu/landscape/events/spotted-lanternfly-preparedness-conference


Other Upcoming Events:​t

  • 2/19: Principles and Fundamentals of Weed Science (part A1 of the Invasive Plant Certification series), Milford, MA
  • 3/5: Community Tree Conference: Species Selection in the Urban Landscape - Professional Perspectives
  • 3/14: State Regulations Pertaining to Invasive Plant Management (part A2 of the Invasive Plant Certification series), Milford, MA
  • 3/19:  The Invasive Plant Issue and Invasive Plant Identification (part A3 of the Invasive Plant Certification series), Milford, MA
  • 3/28:  Spring Kickoff: UMass Extension Landscape Education Day, Wareham, MA
  • 4/9:  Developing an Invasive Plant Management Program (part B of the Invasive Plant Certification series), Milford, MA

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


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 Turf Management Updates

For home gardeners and garden retailers - Check out 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, see https://twitter.com/UMassGardenClip

Diagnostic Services

A UMass Laboratory Diagnoses Landscape and Turf Problems - 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, see Plant Diagnostics Laboratory

Soil and Plant Nutrient Testing - 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.