UMass Extension's Landscape Message is an educational newsletter intended to inform and guide Green Industry professionals in the management of our collective landscape. Scouts compile and record environmental and phenological data for locations throughout Massachusetts to aid in the monitoring of plant and pest development, the planning of management strategies, and the creation of site-specific records for future reference. Detailed reports from Extension specialists on growing conditions, pest activity, and cultural practices for the management of woody ornamentals, trees, and turf are regular features. UMass Extension has updated the following issue to provide timely management information and the latest regional news and environmental data.
The Landscape Message will be updated weekly April through June. The next message will be available on May 8. To receive immediate notification when the next Landscape Message update is posted, be sure to join our e-mail list.
Scouting Information by Region
Regional Notes
Cape Cod Region (Barnstable)
General Conditions: The grey, cool conditions returned to the Cape for this reporting period. Making it feel even colder, most days experienced brisk winds and occasional drizzle, but with little in the way of accumulation. Plant development seems to be a bit behind compared to previous years. Some deciduous trees such as crabapple and willow are beginning to leaf out. Most perennials have yet to break dormancy. Pansies are ready to plant and brighten an otherwise dormant garden. Lungwort (Pulmonaria sp.) and Bloodroot (Sanguinaria sp.) are blooming in the garden. Spike winter hazel (Corylopsis spicata) and Buttercup winter hazel (C. paucifolia) are in full bloom. Norway maple (Acer platanoides) is beginning to bloom. Lawns are getting quite green and it will soon be mowing season. Pests/Problems: Winter moth caterpillars have been observed in the buds of blueberry by Larry Dapsis, entomologist with the Cape Cod Extension. The hatch has positively begun and will continue over the next week or so, depending on weather conditions. Few other pest have been observed yet. Deer ticks are very active. Be sure to use a repellent when working outdoors and perform a thorough tick check at the end of the working day. Winter annual weeds such as bittercress (Cardamine hirsuta) and shepherd’s purse (Capsella bursa-pastoris) are in bloom. Now that forsythia is in bloom, it is time to use pre-emergent crabgrass control.
Southeast Region (Hanson)
General Conditions: Weather for the past week has remained cool with sufficient moisture to keep plant development in check. Hanson received 0.51 inches of rain and soils are moist. Although cool, it is nice to see spring color and the cool weather has helped to keep that color! Plants like Star magnolia, Magnolia ‘Wada’s Memory’, Lonicera fragrantissima (Winter honeysuckle), and Abeliophyllum distichum remain in bloom and in previously warmer springs, these plants would have been in bloom for maybe a few days instead of almost 2 weeks! Adding to the spring landscape, the following plants are in full bloom: Norway maple, Magnolia soulangiana (Saucer Magnolia), Magnolia kobus var. loebneri ‘Leonard Messel (Magnolia 'Leonard Messel'), Corylopsis spicata, Corylopsis pauciflora, Lindera benzoin (Common Spicebush), Cornus officinalis, Cornus mas, Rhododendron mucronulatum, Forsythia, Pieris japonica, Pieris floribunda, Pieris ‘Brouwer’s Beauty’, Salix sp. (pussy willow), heaths, heathers, Petasites japonicus (Japanese butterbur), Anemone sp., Primula sp., Omphalodes verna, Corydalis solida, Sanguinaria canadensis ‘Multiplex’ (Double Bloodroot), Pulmonaria, hyacinths, Brunnera macrophylla, Dicentra cucullaria (Dutchman’s Breeches), Pachysandra terminalis, Helleborus foetidus, Helleborus xhybridus, (Lenten Rose), Trillium, daffodils, Scilla sibirica, Hepatica, early tulips, Ranunculus ficaria and Vinca minor are in full bloom. While scouting, I saw a garden planted with marigolds. Remind clients that tender annuals should not be planted until the end of May. Pests/Problems: Winter moth caterpillar eggs finished hatching, around April 25th, in Hanson and the tiny black caterpillars are about the size of the tip of an eyelash. Once the caterpillars start feeding and grow, they will turn a light, pale green. Monitor the developing expanding buds of maples (oak, Japanese, silver, red, Norway, sugar), birch, crabapple, apple, beech, blueberry and other susceptible plants and manage these caterpillars early to avoid extensive damage. Sampling several Norway maple buds revealed 7 tiny winter moth caterpillars per bud! (That is a lot!). Some tree buds, like oak, are still tight and not fully opened yet, and with plant development delayed, it may be difficult to find caterpillars initially, but continue to monitor the tree buds for winter moth caterpillars. Warmer weather is predicted next week and we should have more information on winter moth caterpillars and where they may be problematic. Bright red lily-leaf beetles were found feeding on true lilies. Eastern tent caterpillars and their webs were found in the branch crotches of wild cherry and crabapple. Remove and destroy webs and caterpillars now. Ants, mosquitoes, deer ticks, hover flies, honeybees, carpenter bees, bumblebees, and solitary bees are active. Continue to take precautions against deer ticks to avoid being bitten. Monitor for European pine sawfly and Hemlock woolly adelgid. Winter damage to evergreens and broadleaved evergreens (Cryptomeria, Thuja ‘Green Giant’, pines, boxwoods, hollies, etc.), along with the amount of damage to trees and shrubs from the past winter storms, continues to be seen and commented on. Landscape cleanups are going ‘full-throttle’ and there is a lot to be done. Reports of severe damage to trees and shrubs from rabbits continue to come in; also, reports of vole damage to lawns, perennials, and woody plants. A few dandelions were seen in bloom but for the most part, dandelion season is not here yet. Bittercress continues to flower and some plants are setting seed. Deer and rabbits continue to browse and feed on favorite plants.
North Shore Region (Beverly)
General Conditions: This was relatively cool period with overcast skies on most days had temperatures in the 40s during the night and 50s during the day. We gained only 6 growing degree days during this reporting period, and approximately 0.11 inches of rain were received at Long Hill. It was also a windy week with wind speeds in double digits (10-14 mph) on most days except on Saturday and Sunday. Spring cleanup is taking place on many landscapes and the soils are moist and suitable for planting. Woody plants in full bloom include: Giraldi forsythia (Forsythia giraldiana), Tremonia border forsythia (Forsythia x intermedia “Tremonia”), Leatherwood (Dirca palustris), Cornelian cherry dogwood (Cornus mas), Star magnolia (Magnolia stellata), Merrill magnolia (Magnolia x loebneri “Merrill”), Anise magnolia (Magnolia salicifolia), Winter hazel (Corylopsis winterthur), Red maple (Acer rubrum), Pieris (Pieris japonica), Winter honeysuckle (Lonicera fragrantissima), Fragrant viburnum (Viburnum farreri), Korean rhododendron (Rhododendron mucronulatum), Weeping forsythia (Forsythia suspensa), White forsythia (Abeliophyllum distichum), Beatrix Farrand forsythia (Forsythia x intermedia “Beatrix Farrand”) and Daphne (Daphne spp.). Woody plants beginning to flower include: Weeping Higan Cherry (Prunus subhirtella), Japanese hornbeam (Carpinus japonica). Herbaceous plants in bloom include: Trout lilies (Erythronium americanum), Daffodils (Narcissus spp.), Bloodroot (Sanguianaria canadensis), Puschkinia (Puschkinia libanotica), Siberian Squill (Scilla Siberica), Christmas Rose Hellebores (Helleborous x hybridus) and Native Pachysandra (Pachysandra procumbens). Pests/Problems: Deer browsing has been reported on perennial gardens. There is some significant mole tunneling on some lawns. Some landscapers are spraying for winter moth larvae especially in areas where there was significant winter moth activity last year. Ticks are very active and so be sure to check yourself for ticks after spending time in the yard.
East Region (Boston)
General Conditions: We have slowly accumulated 9 Growing Degree Days over the past 7 days for a total of 50.5. Average high temperatures have been in the mid 50’s with lows in the 40’s. The soil remains moist, we received 0.15” of heavy precipitation overnight on the 27th. Despite the consistently cooler than average temperatures the landscape is greening up and becoming more colorful. Salix sp. (willow) have begun to leaf out and are adding green and yellow color to the canopy in the meadow. The moderate temperatures have allowed early magnolias to hold their blossoms and continue flowering. Many early cherries are flowering; Prunus nipponica (Japanes alpine cherry), Prunus sargentii (Sargent cherry), Prunus subhirtella (Higan cherry), Prunus tomentosa (Nanking cherry) and many cultivars. Amelanchier arborea (downy servicetree), Pachysandra procumbens (Allegheny spurge), Rhododendron mucronulatum ‘Cornell pink’, Spiraea prunifolia (bridalwreath spirea) and Vinca minor (periwinkle) are in full bloom. Zanthorhiza simplicissima (yellowroot) is flowering; the flower pannicles are small and insignificant if grown individually, but planted in a mass add colorful shades of red/ purple to the understory. Pests/Problems: Weeds continue to thrive under the current conditions. Many annuals are germinating and colonizing any available bare soil. Biennials Chelidonium majus (greater celandine) and Alliaria petiolata (garlic mustard) continue to gain in size. Glechoma hederaceae (ground-ivy) is in full bloom. Viola sp. (violets) are blooming in unmanaged turf. Winter moth (Operophtera brumata) continues to hatch and is feeding. Viburnum leaf beetle (Pyrrhalta viburni) larvae are active. Alder, birch and juniper continue to contribute pollen.
Metro West (Acton)
General Conditions: What a strange week it’s been! I woke to snow on Arbor Day, last Friday, the 24th. Thankfully, it was barely a dusting and didn’t hang around for long. There still remains a pile of snow on a property from a roof top removal that I drive by each day and to and from work. Little did I think that it would be around for this long! With the rain, soils remain moist and are suitable for planting. Although it has been windy with gusts up to 24 mph this past week, so take care with roots and watering. Both flower and leaf buds on a number of different woody plants, some of which include Amelanchier (Shadbush, Serviceberry), Malus (Apple, Crabapple), Prunus (Cherry), Pyrus (Pear), Syringa (Lilac), and Viburnum are swelling and ready to burst. Woody plants seen in bloom this past week are Acer rubrum (Red Maple), Chaenomeles speciosa (Common Flowering Quince), Cornus mas (Cornelian Cherry Dogwood), C. officinalis (Japanese Cornelian Cherry Dogwood), Forsythia spp. (Forsythia), Hamamelis x intermedia 'Diane' and H. 'Arnold Promise' (Witchhazel), Magnolia x loebneri 'Merrill', M. soulangiana (Saucer Magnolia), M. stellata (Star Magnolia), Lindera obtusiloba (Japanese spicebush), Pieris japonica (Japanese Pieris) and Rhododendron mucronulatum (Korean Rhododendron). Contributing even more color and interest to the landscape are some flowering herbaceous plants and spring ephemerals including: Asarum europaeum (European Ginger), Caltha palustris (Marsh Marigold), Chionodoxa luciliae (Glory of the Snow), Crocus spp. (Crocus), Dicentra canadensis (Squirrel Corn), D. cucullaria (Dutchman's Breeches), Epimedium sp. (Barrenwort), Helleborous x hybridus (Christmas Rose), Hyacinthus spp. (Hyacinth), Mertensia virginica (Virginia Bluebells), Muscari sp. (Grape Hyacinth), Narcissus spp. (Daffodil), Omphalodes verna (Blue-eyed Mary), Pachysandra procumbens (Allegheny Spurge), P. terminalis (Japanese Pachysandra), Petasites japonicus (Japanese Butterbur), Primula spp. (Primrose), Pulmonaria longifolia (Lungwort), Puschkinia libanotica (Striped Squill), Sanguinaria canadensis (Bloodroot), S. canadensis 'Multiplex' (Double Bloodroot), Scilla siberica (Siberian Squill), Trillium erectum (Red Flowering Trillium), Tulipa spp. (Tulip), Vinca minor (Periwinkle) and Viola spp. (Violet). Pests/Problems: Acer platanoides (Norway Maple) is in full bloom. This invasive tree is hard to miss now that it is in bloom and its flowers are yellowish-green and it is found growing most everywhere. Ticks are active so continue to monitor yourself and others for these parasites. Wear light color clothes to make the job easier on you. Also, seen flourishing everywhere is the basal foliage of Alliaria petiolata (Garlic Mustard). Other weeds seen in bloom but without the invasive tendency of the previous two mentioned are: Glechoma hederacea (Ground Ivy) and Lamium purpureum (Purple Dead Nettle).
Central Region (Boylston)
General Conditions: Temperatures have been cool with frost & freeze warnings on Thursday, Friday & Saturday nights, and actual temperatures in the 30s F. Daytime temperatures have ranged from the lower 50s to the lower 60s. Plants are slowly coming out of their winter dormancy. In full boom are Magnolia x loebneri ‘Merrill’, Katsura (Cercidiphyllum japonicum); Elm (Ulmus americana), Rhododendron dauricum, Mountain Andromeda (Pieris floribunda), Corylopsis pauciflora, Fragrant Honeysuckle (Lonicera x purpusii), Cornelian Cherry (Cornus mas), Narcissus, early Tulips, Bloodroot (Sanguinaria canadensis), European and Canadian Ginger (Asarum europaeum, A. canadensis), Fumewort (Corydalis solida); Lenten Rose (Helleborus x hybridus), Lungwort (Pulmonaria sp.), Periwinkle (Vinca minor), and early Primrose (Primula denticulata). Budded and ready to go are Shadbush (Amelanchier sp.), Apples & Crabapples (Malus sp.); Cherries (P. subhirtella, P. ‘Okame’, P. sargentii); Saucer Magnolia (M. x soulangeana). Pests/Problems: Ticks and deer continue to be the major problems. Invasive Rosa multiflora and Lonicera morrowii are beginning to leaf out. The scalloped leaves of Garlic Mustard (Alliaria petiolata) are unfurling ahead of our natives.
Pioneer Valley Region (Amherst)
General Conditions: After a rapid ascent into spring weather during mid-April, the “pause” button was pressed on the season’s development this past reporting period. Scattered snow flurries developed on 4/22 into Thursday, 4/23 but there were no accumulations. Friday, 4/24 saw highs only in the mid-40s throughout the Pioneer Valley with gusty winds making it feel almost wintery. The spring winds continue to pummel the valley bottomlands with a maximum gust of 46 mph recorded at Barnes Airport in Westfield on 4/22. Additionally, four of seven days in this reporting period have witnessed maximum gusts over 30 mph. Once the massive low pressure system that hovered over eastern Canada and the northeast finally moved out, warmer air masses have settled in and temperatures have returned to their seasonal averages. Tree and shrub development continues to be slow, especially with the cool period we just experienced. But, with warmer weather progress should move rapidly ahead. The long-term forecast calls for a brief cooling on Friday, 5/1 but then above-average temperatures into the next reporting period. Precipitation was near average in the Pioneer Valley over the month of April with most locations receiving between 3.5 to 4.5”. The lack of shade, gusty winds and low humidity, however, can quickly desiccate succulent plant parts so careful attention should be paid to recently-planted material in the weeks ahead. Pests/Problems: Few pests and pathogens are active at this early stage in the growing season. Rosa species are beginning to leaf out, thus it’s time to begin scouting for rose slug sawfly. Dead canes and fallen leaves should be removed to help control against Diplocarpon. Newly expanding leaves, roughly 7 to 14-days-old are most susceptible to infection. Sugar maples are leafing out in the valley and if we experience a period of wet and mild weather over the next several weeks, maple anthracnose could be a problem on trees that have suffered infections in previous years. Shoots and needles killed by winter weather on junipers and arborvitae should be pruned out soon to avoid colonization by opportunistic pathogens. Kabatina, a fungal pathogen that causes a shoot tip blight on junipers will be active soon. Prune out and discard black knot on Prunus species before trees flush, since the foliage makes it more difficult to locate the galls.
Berkshire Region (Great Barrington)
General Conditions: It’s been a wacky week weather wise, but that is consistent with much of the year thus far. Berkshire residents in most of the county awoke to a covering of snow over the ground on the morning of April 23. Flurries and/or sleet persisted through part of the day. Despite a predicted warm up, temperatures for the Landscape Message reporting period were well below normal, with frost occurring in many areas on five of the seven days. Other than a thunderstorm on April 22, precipitation was sparse. With the large amount of snow this past winter, one might think that precipitation would be above normal. Yet, as of April 29, precipitation for the year is about 2.75 inches below normal. Soil moisture levels range from dry to moist, depending upon drainage, cover vegetation, and topography. Persistent strong winds have hastened drying of most soils. Plant development continues to be very slow. Lawns are greening up and mowing should begin soon. Pests/Problems: Pest appearance continues to be slow. The most active pest is still the blacklegged tick. While it is expected that people working around shrubs, raking leaves, or hiking in woodlands would attract ticks, some who have done nothing more than walk across their lawn have picked up ticks. Kids playing games on turfgrass surfaces have also picked up ticks. It behooves anyone working or playing outdoors to take the usual precautions to protect themselves, especially application of tick repellents containing DEET. Spruce spider mite was observed this past week on dwarf Alberta spruce. Boxwood Leafminers are still in the larval stage and will continue feeding within boxwood leaves for another week of two. Therefore, shearing the foliage now will help reduce the number of emerging adults in mid to late May. Young plants of garlic mustard (Alliaria petiolata) can be seen in landscapes, open woodlands, and in garden beds. In general, this is a good time for weeding out biennial and perennial weeds from garden beds since the ground is still soft and roots of these plants are shallow.
Environmental Data
The following growing-degree-day (GDD) and precipitation data was collected for an approximately one week period, April 23 through April 29. Soil temperature and phenological indicators were observed on or about April 29. Total accumulated GDDs represent the heating units above a 50° F baseline temperature collected via our instruments for the 2015 calendar year. This information is intended for use as a guide for monitoring the developmental stages of pests in your location and planning management strategies accordingly.
|
Region/Location |
GDD |
GDD |
Soil Temp |
Precipitation |
|
Cape Cod |
6 |
46 |
49 |
0.09 |
|
Southeast |
7 |
38 |
59 |
0.51 |
|
North Shore |
6 |
46 |
48.6 |
0.11 |
|
East |
9 |
50.5 |
56 |
0.15 |
|
Metro West |
3.5 |
19.5 |
52 |
0.13 |
|
Central |
11 |
46 |
48 |
0.23 |
|
Pioneer Valley |
9 |
50 |
53 |
0.08 |
|
Berkshires |
3 |
26 |
49 |
0.76 |
|
AVERAGE |
7 |
40 |
52 |
0.26 |
|
n/a = information not available |
||||
Phenology
Phenological indicators are a visual tool for correlating plant development with pest development. The following are indicator plants and the stages of bloom observed for this period:
| Indicator Plants - Stages of Flowering (BEGIN, BEGIN/FULL, FULL, FULL/END, END) | ||||||||
|---|---|---|---|---|---|---|---|---|
| PLANT NAME (Botanic/ Common) | CAPE | S.E. | N.S. | EAST | METRO W. | CENT. | P.V. | BERK. |
| Amelanchier spp. (Shadbush, Serviceberry) | * | * | * | begin/full | * | * | * | * |
| Prunus serrulata (Japanese Flowering Cherry) | begin | * | * | begin | * | begin | begin | * |
| Magnolia x soulangeana (Saucer Magnolia) | * | full | full | full | full | begin | full | * |
| Forsythia x intermedia (Border Forsythia) | begin/full | full | full | full | full | full | full | full |
| Rhododendron mucronulatum (Korean Rhododendron) | begin | full | full | full | full | full | full | begin |
| Magnolia stellata (Star Magnolia) | full | full | full | full | full | full | full | begin |
| Pieris japonica (Japanese Pieris) | full | full | full | full | full | full | full | full |
| Cornus mas (Cornelian Cherry Dogwood) | full | full | full | full/end | full | full | full | full |
| Acer rubrum (Red Maple) | full/end | full/end | full/end | end | full/ end | full/end | full/end | full |
| * = no activity to report/information not available | ||||||||
- CAPE COD REGION - Roberta Clark, UMass Extension Horticulturist for Barnstable County - Retired, reporting from Barnstable.
- SOUTHEAST REGION - Deborah Swanson, UMass Extension Horticulturist for Plymouth County - Retired, reporting from Hanson.
- NORTH SHORE REGION - Geoffrey Njue, Green Industry Specialist, UMass Extension, reporting from Beverly.
- EAST REGION - Kit Ganshaw & Sue Pfeiffer, Horticulturists, reporting from the Arnold Arboretum, Jamaica Plain.
- METRO WEST REGION – Julie Coop, Forester, Massachusetts Department of Conservation & Recreation, reporting from Acton.
- CENTRAL REGION - Joann Vieira, Superintendent of Horticulture, reporting from the Tower Hill Botanic Garden, Boylston.
- PIONEER VALLEY REGION - Nick Brazee, Plant Pathologist, UMass Extension Plant Diagnostic Lab, reporting from UMass Amherst.
- BERKSHIRE REGION - Ron Kujawski, Horticultural Consultant, reporting from Great Barrington.
Woody Ornamentals
Diseases
Recent woody ornamental diseases of interest seen in the UMass Extension Plant Diagnostic Laboratory:
Common boxwood (Buxus sempervirens) infested with the boxwood spider mite (Eurytetranychus buxi) and infected by the fungal pathogen Volutella buxi. Several plants, approximately 10-years-old, have been present at the site for roughly eight years. Browning/yellowing of upper canopy leaves developed over the winter months. Close inspection of the foliage showed the characteristic fleck-like scratches on the upper surface. Winter injury is a likely contributor to the observed dieback. The boxwood blight pathogen was not detected from the submitted sample.
Needle blight of Chinese juniper (Juniperus chinensis) caused by Phyllosticta and Kabatina. Symptoms included shoot tip browning and dieback of foliage on interior branches. Tree is approximately 30-years-old and symptoms were present in years past. Kabatina is often found attacking shoot tips in the spring, especially on plant parts damaged from winter weather and insects.
Winter injury on Japanese snowbell (Styrax japonicus). Young tree, present at the site for only 18 to 24 months, began to exhibit symptoms of dieback in late winter/early spring. The bark at the base of the tree, up to a height of 12” from the soil line, completely separated from the trunk. There was additional bark splitting at higher locations on the trunk as well. Japanese snowbell is hardy to zone 6, making the Commonwealth the northern extent of its planting range. The record cold during February is almost assuredly to blame.
Infestations of Eastern spruce gall adelgid (Adelges abietis) and spruce spider mite (Oligonychus ununguis), needle cast caused by Rhizosphaera and shoot blight caused by Phomopsis on Norway spruce (Picea abies). Several trees in a residential setting, approximately 80 to 90-years-old. Several of the trees are exhibiting a significant dieback of the lower branches. The spider mite infestation was severe and there was a significant population of the adelgid as well. While Norway spruce is highly resistant to Rhizosphaera, trees in decline are susceptible to attack. Phomopsis can be regularly found on shoots of declining spruce. The dieback was only recently noticed but has likely been building in severity for a few years.
Transplant stress and winter injury on ornamental cherry (Prunus sp.). Young tree, present at the site for only 18 months. This spring, splitting and sloughing bark was observed on the lower trunk along with fruiting bodies of the wood-decaying pathogen Irpex lacteus. Irpex is a weak pathogen, typically establishing on branches of hardwoods in steep decline. The tree was planted as a memorial to a family member who passed away and held very strong sentimental value. Unfortunately, the damage appears too severe for continued growth and replanting will be necessary.
Shoot tip blight caused by Diplodia pinea, needle cast caused by Lophodermium and infestation by an unknown scale insect on eastern white pine (Pinus strobus). Forest trees, approximately 10-years-old, growing in an understory setting. Diplodia can be found regularly on eastern white pine but it is uncommon to see the pathogen causing any significant damage. The shoot tip blight was aggressive on lower branches while the scale insect was embedded in the branch tissue just below the whorl and remains to be identified. Eastern white pine is classified as mid-tolerant of shade but if not released from the understory as a sapling can decline rapidly from various pests and pathogens.
Green giant arborvitae (Thuja ‘Green Giant’) suffering from desiccated and browning needles. Shrubs are 4-years-old and were moved two years ago. In 2014, the shrubs suffered from needle blight caused by Phyllosticta thujae. However, pruning of blighted shoots and lower branches to increase air flow coupled with fungicide applications appear to have reduced the fungal population. The damage that appeared in late winter appears to be the result of winter injury. However, Pestalotiopsis was also detected. This common pathogen of arborvitae will take advantage of killed shoot tips to gain entry and spread.
For more detailed management information for woody plant diseases in the landscape, refer to UMass Extension's Professional Management Guide for Diseases of Trees and Shrubs
Report by Nick Brazee, Plant Pathologist, UMass Extension Plant Diagnostic Lab, UMass, Amherst.
Weeds
Treat garlic mustard (Alliaria petiolata) now. Applications at this time of year will control second year plants before they go to seed as well as first year seedlings. Look for seedlings at this time, as these seedlings will be next years flowering plants.
Landscape mulch should be the first defense against weeds in landscape beds. Mulching can be done now at the beginning of the season before summer annual weeds germinate. Freshly mulched landscape beds will not require a preemergence herbicide application because the fresh mulch should supply adequate weed control in the short term. Preemergence herbicide application should be considered now on mulched areas that have not been freshly mulched or a bit later in the season. Preemergence herbicides should be applied on top of landscape mulches not underneath them. Compost is not recommended as a mulching material.
Inspect areas of landscape where new trees or shrubs, especially those that were field grown, have been planted in the last year. Look for perennial weeds that may be growing from the root ball. Canada thistle, mugwort, quackgrass, bindweed and horsenettle are some of the possible culprits.
When scouting for weed in the landscape, observe areas underneath and around bird feeders. Some of the most interesting weeds that are sent to me come from these areas. Many of these plants are from other regions of the country and therefore have the potential to be aggressive and pernicious.
Treat winter annual and perennial weeds in ornamental beds with glyphosate (Roundup ProTM or equivalent) and glufosinate (FinaleTM). These applications are easier if done now before woody ornamentals leaf-out. The new growth of herbaceous perennial ornamentals can be very susceptible to spray drift, so exercise extreme caution. Non-chemical products containing clove oil, citric acid, acetic acid or orange extract can be used on small winter annuals but not on large winter annuals or perennials. Remember these organic/non-chemical products do not translocate and will not control established perennial weeds but will control young winter annual weeds. Many winter annuals are just beginning to flower and have not set seed and should be controlled now.
Common landscape winter annual weeds being observed now are:
- mouse-ear cress (Arabidopsis thaliana)
- thymeleaf sandwort (Arenaria serpyllifolia)
- downy brome (Bromus tectorum)
- shepherd's-purse (Capsella bursa-pastoris)
- bittercress (Cardamine hirsuta)
- sticky chickweed (Cerastium viscosum)
- horseweed (Conyza canadensis)
- spring whitlowgrass (Draba verna)
- henbit (Lamium amplexicaule)
- red deadnettle (Lamium purpureum)
- field pepperweed (Lepidium campestre)
- Virginia pepperweed (Lepidium virginicum)
- pineappleweed (Matricaria matricariodes)
- annual bluegrass (Poa annua)
- knawel (Scleranthus annuus)
- common chickweed (Stellaria media)
- field pennycress (Thlaspi arvense)
- corn speedwell (Veronica arvensis)
- purslane speedwell (Veronica peregrina)
Japanese knotweed, Polygonum cuspidatum, has begun to emerge from rhizomes. Do not attempt to control this weed at this time as herbicide applications are not effective. Repeat cutting or mowing can be used as a non-chemical strategy and if that is the control strategy selected then cutting and mowing should begin now. Repeat cutting or mowing should be done as regrowth reaches 4 to 6 inches.
Report by Randall Prostak, Weed Specialist, UMass Extension Agriculture & Landscape Program, Amherst.
Landscape Turf
Management Practices
First Fertilizer Application… When?
Tightening nutrient management regulations in Massachusetts and beyond have brought increased focus on turf fertilizer programming and fertilizer applications. As previously covered in this space, a primary goal for fertilizer programming is to time maximum nutrient availability to coincide with periods of peak turfgrass growth. In the spring, the window of ideal growing conditions is relatively short – sandwiched between the recession of winter and subsequent recovery, and the arrival of hotter, drier conditions that cause summer-related stress and associated growth and management challenges.
This spring, winter has been very slow in letting go, and many are itching for the season to ramp up. A popular topic of conversation is the appropriate timing for that first spring fertilizer application. One thing that the turf system needs after the snow melts and the soil begins to thaw, especially after a winter like we just experienced, is time. From a nutrient perspective, water must be free and in liquid form for nutrients to be mobile in soil and available for plant uptake. Fertilizer applied too early, when soil has not thawed completely and/or stand density has not recovered sufficiently from winter shoot dieback, has a much greater potential of being carried out of the turf system with runoff.
Roots also need to be active and viable for nutrient absorption to occur. Harsh winter conditions cause roots to die back, therefore a degree of root system recovery should take place prior to fertilizer application. The physical passage of mineral nutrients from the soil into root tissue, furthermore, is a largely active process for which energy is required. This means that photosynthesis and other biological functions must be up and running to adequately supply this energy. Nutrients in the soil solution that are not taken up promptly may be subject to loss through leaching.
The simple solution to promote robust plant uptake and minimize loss is to wait to fertilize in the spring until growth is solidly established, with the minimum threshold being the point of approximately 50% green-up. Contrary to what some believe, fertilizing early will not stimulate earlier growth; the onset and acceleration of both shoot and root growth are largely temperature dependent. Also, the calendar is never really useful in this regard, because of often significant year-to-year variation (at this time in 2012, Boston had 235 growing degree days; this year as of this writing, 51). Further variation can be introduced by many factors including geography, ambient temperatures, soil temperatures, soil moisture levels, exposure, etc. While sunny sites on the Cape may be ready, for example, sheltered locations in the Berkshires may need some more time. The progression of aerial shoot growth and green color (see photo above right) are built-in signals that account for all of the above factors.
It is important to remember and keep in perspective that the aim is to maximize plant uptake while simultaneously minimizing nutrient loss from the system. Nutrients lost to the environment, most notably nitrogen and phosphorus, have a much greater potential of reaching and accumulating in ground and surface waters. In addition, nutrient loss is wasteful of limited time, labor, fertilizer, and financial resources. Nutrients that leave the system will not support the desired response in the turf, and may lead to performance and management problems and increase the need for future inputs.
For a final, related tip, don’t let combination products be your boss when it comes to application timing. While the intent of fertilizer/pesticide combination products is to ‘kill two birds with one stone’ for the sake of efficiency and convenience (fertilizer and pre-emergence herbicide, for example), the timing for one objective may have to be compromised in support of getting the correct timing for the other objective. If the compromise will be significant, opt for separate fertilizer and pest control applications for greater accuracy and control.
Report by Jason Lanier, Extension Educator, UMass Extension Agriculture and Landscape Program, Amherst
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