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
Early-bird rate ends 9/24 for Green School!
UMass Extension's Green School is a comprehensive certificate short course for Green Industry professionals taught by UMass Extension specialists and University of Massachusetts faculty.
Location: Doubletree Hotel, Milford, MA
Dates: October 29 - December 13, 2018, twice weekly from 9:00 am to 3:30 pm
http://ag.umass.edu/landscape/education/umass-extensions-green-school
Designed for landscapers, lawn care specialists, nursery operators, sports field managers, public and private grounds managers, arborists and others in the green industry, our comprehensive course is for horticultural professionals who want to gain an understanding of economically feasible and environmentally responsible plant and land care practices and the relation of those practices to protecting the environment. Both experienced professionals as well as those entering the green industries will benefit from this course. Instruction is done via classroom style lecture and interactive activities, and is supplemented through online resources via an online learning management system.
THREE SPECIALTY TRACKS TO CHOOSE FROM
- Landscape Management
- Turf Management
- Arboriculture
For more details or a registration form, go to www.umasgreeninfo.org or call (413) 545-0895.
Questions & Answers
Q. I just learned that a property I manage has wild parsnip growing in a small area. Is this plant toxic and do I need to be concerned?
A. Yes, you definitely need to be concerned. The first step is positive identification. Wild or field parsnip, Pastinaca sativa, is a member of the carrot family (Apiaceae). Wild parsnip is an herbaceous, biennial plant growing 2 to 5 feet tall with occasional branching. The stems are glabrous, angular, and furrowed. The alternate leaves are oddly pinnate, consisting of about 9 leaflets that are mostly hairless. The lower compound leaves are up to 18" long and 6" across with long petioles. The upper compound leaves are much smaller with short petioles. The individual leaflets are up to 3" long, 2" across, and ovate or elliptic in outline with cleft lobes and coarse teeth along the margins. Visit the UMass Extension Weed Herbarium wild parsnip page http://extension.umass.edu/landscape/weeds/pastinaca-sativa to view photos for positive identification.
Health concerns arise when the sap contacts your skin. The sap of wild parsnip contains chemicals called psoralens (precisely, furocoumarins) that cause what dermatologists call "phyto-photo-dermatitis." That means an inflammation (itis) of the skin (derm) induced by a plant (phyto) with the help of sunlight (photo). When absorbed by skin, furocoumarins are energized by ultraviolet light from the sun, causing them to bind with nuclear DNA and cell membranes. This process destroys cells and skin tissue. In mild cases, affected skin reddens and feels sunburned. In more severe cases, the skin becomes red followed by blisters and, for a period of time, the area will feel as if it has been scalded. Often visible and permanent scaring occurs after blisters heal. Wild parsnip is known to occur in all counties of Massachusetts, but from my observations, this species is more prevalent in the four western counties of the state.
Q. In the middle of July, we applied a postemergence treatment of Drive XLR8 for crabgrass. About half the crabgrass was controlled and there were no signs of injury on the other half. Could this be herbicide resistance?
A. I will rule out herbicide resistance until we explore further. The active ingredient in Drive XLR8 is quinclorac. Quinclorac will control smooth and large crabgrass from the 1-leaf to 1-tiller stage and 5-tiller to flowering. Quinclorac will not control crabgrass in the 2 to 4-tiller stage. I suspect that your application in the middle of July controlled the crabgrass that was in the 5-tiller or larger stage and missed the plants in the 2 to 4-tiller stages, as not all crabgrass at a specific site will be at the same growth stage at the same time.
Q. One of my customer has horses and they are salivating excessively. We treated the lawn with an herbicide about 100 yards from the horse pasture. The customer suggests that the herbicide is causing the horse’s sickness. Is this possible?
A. Even if you treated the pasture, I am unaware of any incident were the horse would have such a problem. Your treatment was quite a distance away and we should explore other causes for excessive salivation. One of the most likely causes of this symptom is horses is the occurrence of clover in the grazed pasture and/or hay. White clover and red clover are perennial plants commonly found in pastures and hayfields in New England. White clover can tolerate intense grazing and is often found in overgrazed pastures. When the clover plants are stressed from continuous grazing or during periods of drought or extremely hot, humid weather, the Rhizoctonia fungus can grow rapidly on the clover leaves. The fungus produces a toxin called slaframine that stimulates the salivary glands of horses, causing them to drool excessively. If the fungus is growing on red clover that is baled for hay, it will persist and can cause horses to drool when they consume the hay. This condition is appropriately called “clover slobbers in horses”.
Removing the horses from the pasture, feeding them hay that is free of clover, and suppling a fresh water source will allow you to determine if the clover in the pasture or hay is the offender. When fed an alternative hay, the drooling should stop within a day or two. If drooling continues, it would be wise to contact a veterinarian to explore other possible causes. The drooling is normally only a nuisance and will not harm the horse. It is not abnormal for some horses in the pasture to be more affected than others, since horses vary in their sensitivity to the toxin and their preference for clover. While removing the animals from the pasture and not feeding them hay containing clover is a great diagnostic tool, a long-term solution would be to treat the pasture in an attempt to decrease the amount of clover. Your customer is welcome to contact me if they have questions about clover management and clover slobbers.
Randy Prostak, UMass Extension Weed Specialist
Trouble Maker of the Month
Too Much Rain!
This summer was a wet one here in the Pioneer Valley, and many gardeners saw root, crown, and stem rots in their annuals and perennials. There are a number of pathogens that can cause these rots in the summer including Phytophthora, Fusarium, Rhizoctonia, Verticillium, and Sclerotinia. All of these are encouraged by humidity, wetness, and warm temperatures. In addition to encouraging pathogens, chronically soggy soil is detrimental to plant health because water displaces air in the soil, depriving roots of the oxygen they need.
Plant pathologists like me are forever telling people to improve drainage if their soil is too wet. So how do you know if you soil really is poorly drained? Here’s an easy way to test that:
- Dig a hole 12” in diameter and 12” deep
- Fill the hole with water and let it sit 12-24 hours
- When it has drained completely, fill the hole with water again
- Measure and record the water level once every hour until the water is gone. Ideal soil drainage is about 2” per hour average, with hourly rates between 1” and 3”. One inch or less is too slow, and >4” too fast.
While there is nothing you can do about the weather, there are some things you can do to improve poorly drained soil and give your plants a fighting chance should such conditions reoccur next year. Growing in raised beds is chief among these.
Some basic things to consider when contemplating raised beds:
- Location and plant choices. Ideally, plants that like full sun want to have at least 6 hours of direct sunlight per day. Plants that like partial shade will appreciate that shade most in the afternoon. Full shade plants want no more than 3 hours of direct sun. If trees and shrubs are encroaching on your sunny perennial bed, consider pruning. Numerous references on the topic of raised bed construction and maintenance are available; some good ones are listed below.
- Topsoil and compost blends are often used in raised bed construction. Amending the existing soil with compost can also improve drainage. Adding sand can sometimes help, but don’t use sand if your soil contains a lot of clay - mixing sand and clay is how bricks are made! Some references on the topic of soil amendments are listed below.
- Use an edging or framing material for the borders of your bed. Common materials for this use include stone, landscape timbers, and metal edging. Edging will help prevent your lawn from creeping into the bed and the bed from creeping into the lawn.
- Consider installing drip irrigation to make supplemental watering easier when rain is scarce. Drip is preferable to overhead irrigation when it comes to disease control because foliage remains dry.
If raised beds are not for you, you can always make those wet areas work for you by choosing plants that are adapted to wet soils. These include certain varieties of milkweed, hosta, ferns, phlox, Siberian iris, filipendula, and aster.
References for soil amendments:
http://articles.extension.org/pages/61063/materials-to-improve-drainage-in-soil
http://rocklandcce.org/resources/improving-drainage-in-soil-rockland
http://extension.colostate.edu/topic-areas/yard-garden/choosing-a-soil-amendment
References for raised bed construction:
http://chemung.cce.cornell.edu/resources/making-a-raised-bed-garden
https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/fs270_1.pdf
https://cdn-ext.agnet.tamu.edu/wp-content/uploads/2016/05/EHT-078-building-a-raised-garden-bed.pdf
Angela Madeiras, UMass Extension Plant Pathologist
Plant of the Month
Acer griseum, Paperbark Maple
A great small tree as a specimen or for small landscapes, Acer griseum is slow growing to 20-30’ tall and 15-25’ wide. The common name, paperbark maple, hints to the wonderfully ornamental exfoliating bark. The cinnamon red to orange to brown outer bark peels to reveal and contrast with the lighter tan inner bark. Bark on the trunk and stems peels into large curls while some areas can be almost smooth, creating a dramatic look and multiple seasons of interest.
The trifoliate leaves add another form of interest. Leaves are 3-5” long with coarsely toothed leaflets and are green to gray-green on the top and blue-green underneath. Fall color can be variable – sometime orange and red other times red-green or bronze-green. Flowers occur in April to early May and are not ornamentally significant. Flowers are followed by winged samaras.
Propagation of the species is difficult, which contributes to sometimes low availability in the trade. Acer griseum has no serious insect or disease problems. Paperbark maple is a great specimen tree or tree for small areas, and can be used as an understory tree in the woodland garden. It should be planted in a location where the ornamental bark can be appreciated.
Mandy Bayer, Extension Assistant Professor of Sustainable Landscape Horticulture, University of Massachusetts Amherst
Upcoming Events
Sept 24 - Early-bird registration rate ends for Green School
UMass Extension's Green School is our bi-annual certificate course, scheduled for this fall in Milford, MA. Green School meets twice per week starting October 29 and runs through December 13, 2018. Three educational tracks are offered: Landscape Management, Turf Management, and Arboriculture. Green School will not be offered again until fall 2020.
For eligible employers, the Green School registration fee may be partially reimbursed through the Massachusetts Workforce Training Fund Express Grant Program. Employers need to submit an online application to the Express Grant program at least 6 weeks in advance of UMass Green School's starting date. To find out if you qualify and to apply for benefits, go to workforcetrainingfund.org/programs/express-program
For complete information about Green School, including the schedule, curriculum, and registration information, go to ag.umass.edu/landscape/education/umass-extensions-green-school
Other Upcoming Events:t
- 9/24: End of early-bird registration rate for Green School
- 10/15 Last day to register for Green School
- 10/29: First day of Green School
- 11/27 Fall Wrap-up - Hadley, 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.
