Landscape and nursery
§ Salt damage and warranty issues
Turfgrass
§ Summer turf musings
§ Scouting for weeds: black medic, birdsfoot trefoil and yellow woodsorrel
§ Turfgrass Field Day
Christmas trees and forestry
§ Christmas trees and nursery insect update
§ Gypsy moth spray window update
Around the home
§ Some cool bugs are out and about
§ Carpenter
bees wreaking havoc in
§ Elm flea weevils
§ Gypsy moth outbreak appears to be statewide
§ Juniper scale crawlers are emerging
§ A few words about the swarms of mosquitoes that are out right now
§ Christmas peppers
Other news
§
Update of
§ Weather news
Next issue: July 10
Bert Cregg
Horticulture and Forestry
As we noted in an earlier CAT alert (May 2, 2008), last winter was a season of heavy snowfall and therefore, also a year of heavy de-icing salt application. In fact, in many parts of the state salt usage was so heavy that salt was in short supply or completely unavailable by the end of the winter. Along with heavy de-icing salt application comes the potential for plant damage.
Salt damage or potential salt damage can be especially vexing for landscapers that offer plant warranties. Imagine the frustration of a professional landscaper that selects quality plant material, uses proper planting techniques, waters and coaxes the plants through the summer and fall, only to see them damaged by deicing salt. The problem can be especially difficult for landscape installers that provide plant warranties. Plant warranties vary and some exclude problems associated with improper maintenance or damage caused by external agents. Depending on the warranty, salt damage may be excluded. This then raises the question, how do we determine if landscape plants were damaged or killed by salt? Most landscape problems caused by abiotic problems require some detective work and finding a “smoking gun” is more the exception that the rule. With that in mind, here are some clues that point to salt damage as a causal factor.
Damaged plants are
near a road, highway, parking lot or sidewalk that is salted during the winter.
Damage decreases with
distance from the source. A study of de-icing salt impacts to roadside
plants in
Damage is greater on the side of trees facing the roadway. The most dramatic causes of de-icing salt damage are caused by acute exposure of above ground portions of plants to aerial drift. Therefore parts of the plant facing the exposure are most damaged.
Damage is greater on salt-sensitive plants. In general, evergreen plants are more sensitive to salt damage than deciduous plants since evergreen leaves are exposed to salt during the winter. Even within evergreens, however, salt sensitivity can vary widely. White pine and red pine are highly sensitive to salt whereas Austrian pine and ponderosa pine are relatively tolerant of salt exposure.
Plant tissues contain elevated levels of sodium or chloride. Healthy plants contain some sodium and chloride. In fact, chloride is an essential nutrient element for plants. However, when either sodium or chloride builds up in plants, especially in leaves, toxicity can occur. The toxicity levels in foliage vary, but foliage browning is often associated with leaf concentrations (percent dry weight) in excess of 0.5 percent for sodium and 1.0 percent for chloride.
Soil salt levels may or may not be elevated. Both sodium and chloride can be leached from soils. As winter snowmelt is followed by spring rain, deicing salts may be leached and therefore may not show up in soil samples collected in late spring when plant damage becomes apparent.
Eliminate other causes. It’s easy to assume that roadside plants that die or are damaged over winter were injured by de-icing salt. It is still important to do a good detective job and look at other causes. How is the soil pH? Soil drainage? Were there any other chemical applications on the site such as herbicides or fertilizers? Are their potential pest problems? Did you install similar plant materials elsewhere? Did they have similar problems? If not, what was different about the sites?
Kevin Frank
Crop and Soil Sciences
The dry conditions that persisted across much of
On the weed front, it seems that almost everything is active now and making in-roads into the turf. Some of the weeds that I’ve been observing include black medic, white clover, crabgrass, birdsfoot trefoil, and oxalis (yellow woodsorrel). In my random observations black medic appears to be particularly pesky in many lawns. Crabgrass has certainly found a home in many areas but the cool temperatures seemed to have at least slowed down its development up to now. If you’re looking to go after the crabgrass, it would be good to get after it sooner rather than later as the younger crabgrass will be easier to control. For the broadleaf bandits that may be troubling you, if they’re flowering its the second best time to control them. Of course, fall applications for broadleaf weed control are still considered the most effective.
Steven Gower
Diagnostic Services
The yellow-flowered, compound-leafed weeds are now in full bloom in our lawns. The culprits include black medic, birdsfoot trefoil and yellow woodsorrel. These weeds all have small yellow flowers and compound leaves. Just as with any other pest, identification of these yellow-flowered weeds is important to understanding why they are in the lawn. Is the site low in nitrogen? Is the site drought stressed? Are you mowing too low? These could be just a few reasons why black medic, birdsfoot trefoil and yellow woodsorrel are thriving in the lawn.
Understanding and addressing the cultural conditions that promote certain weeds in the landscape, will certainly provide more control than any herbicide treatment alone. Improving these cultural conditions in combination with an herbicide treatment can be very effective. Herbicides that have good activity on black medic, birdsfoot trefoil and yellow woodsorrel in the lawn include 2,4-D, dicamba, triclopyr, clopyralid or mixtures of these active ingredients.
Black medic: (Medicago lupulina L.)
Family: Fabaceae (Legume)
Life cycle: Prostrate, trailing summer annual.
Leaves: Alternate, compound – with three oval to egg-shaped leaflets – hairless to sparsely hairy, shallowly toothed along the upper half and tipped with a small point. The central leaflet is found on a definite stalk; the two lateral leaflets are nearly stalkless. A pair of stipules is present at the base of each petiole.
Stems: Prostrate,
trailing to ascending stems are wiry, usually hairy, multibranched from the
base and up to 2 feet long.
Flowers and fruit: Numerous, very small, yellow flowers are formed in dense, mostly globe-shaped, cloverlike clusters. Fruit are clusters of black, coiled, kidney- to bean-shaped, one-seeded pods.
Reproduction: Seeds.
Birdsfoot trefoil: (Lotus corniculatus L.)
Family: Fabaceae (Legume)
Life cycle: Mat-forming
perennial.
Leaves: Alternate,
compound with five generally oval and smooth-margined leaflets. Each compound
leaf has three terminal leaflets and two reduced leaflets near the stem.
Stems: Prostrate and spreading to semierect stems are herbaceous, branched from a tough crown and up to 3 feet long. Plants form mats by stolons and rhizomes.
Flowers and fruit: Bright
yellow, pealike flowers, sometimes streaked with red, are found in flat-topped
clusters at the ends of long stalks. Fruit are several linear, cylinder-shaped
pods formed in the shape of a bird’s foot. Each capsule contains several
roundish, shiny, olive to black seeds.
Reproduction: Seeds, stolons and rhizomes.
Yellow woodsorrel: (Oxalis stricta L.)
Family: Oxalidaceae (Woodsorrel)
Life cycle: Low-growing
annual or simple perennial.
Leaves: Cotyledons
are rounded to oblong. Gray-green leaves are alternate, compound and
cloverlike, with three heart-shaped leaflets that attach at the pointed ends.
Long-stalked leaves have smooth surfaces, but they are fringed with hair along
the margins.
Stems: Low-growing,
prostrate to erect stems with minimal branching at the base, up to 20 inches tall.
Plants spread by long, slender rhizomes.
Flowers and fruit: Yellow
flowers with five petals are found in long-stalked clusters. Fruit are ridged,
hairy, cylinder-shaped capsules with pointed tips that range from 0.5 to 1 inch
in length. The capsules explosively eject small seeds with a sticky coating up
to several feet away. Seeds are mostly brown, ridged, oval and flattened.
Reproduction:Seeds
and rhizomes.
Note: Identification information for more weeds is available in the new field guide An IPM Pocket Guide for Weed Identification in Nurseries and Landscapes. To order, call 517-353-6740 or visit: http://www.ipm.msu.edu/pdf/pocketGuidesLandsc07.pdf
Kevin Frank
Crop and Soil Sciences
The 2008 Michigan Turfgrass Field Day at the
Jill O’Donnell
Christmas Tree ICM educator
We have had several cases of conifer root aphids on Fraser fir. What we first noticed was that the young transplants were exhibiting yellowing and stunting of growth. The symptoms are very similar to symptoms of environmental stress or nutrient problems. When we dug up the plants, we found large colonies of white root aphids on the roots. They appear to be Prociphilus sp. aphids. These species of root aphids feed on conifer roots for part of their lifecycle and then become woolly aphids that feed on ash trees and other hosts. They appear as large, white aphids on the roots. Even though the trees are showing signs of stress, it is not really known how much damage the aphids cause to their conifer host. It may be that the trees are under stress from grubs, disease damage, transplant shock, improper planting (“J” rooting), poor nutrition, water stress or off-site planting and that the aphids are a secondary stress.
This week we found woolly aphids feeding on new growth of
Norway spruce in the
Eriophyid mites, are also known as rust mites. This group of
mites is very, very small and are often difficult to see with a hand lens. They
are generally colorless and are often identified by the damage they cause, a
bronzing (rusting) of foliage. These minute mites can cause significant damage
on
Mike Bryan
MDA
Growers should note that for Zone 4 the spray window closing date for Dimilin has been set as Saturday, June 28 and the closing date for all other compounds has been set as Friday, July 4. For Zone 5 the closing date for Dimilin has been set for Thursday, July 3. The following chart shows actual and projected open/close dates for application of the two groups of pesticides used for regulatory treatment of gypsy moth in nursery stock and Christmas trees. We are listing the projected dates as guidelines to help you plan your pest management program. Since gypsy moth development will vary by location, you will need to monitor development around your farm. Weather conditions will affect caterpillar development and may effect end date of the spray windows. Growers should watch the Landscape Alerts for additional announcements.
|
Zone |
Open – Dimilin (150 DD*) |
Open – all other compounds (200 DD) |
Close – Dimilin (700 DD) |
Close – all other compounds (800 DD) |
|
1 |
May 1 |
May 6 |
June 15 |
June 21 |
|
2 |
May 1 |
May 6 |
June 15 |
June 21 |
|
3 |
May 6 |
May 17 |
June 21 |
June 28 |
|
4 |
May 10 |
May 21 |
June 28 |
July 4 |
|
5 |
May 16 - Lower |
May 27 – L.P. counties only in Zone 5 |
July 3 |
July 11 (projected) |
|
5 |
June 5 - |
June 9 - U.P. counties only in Zone 5 |
July 3 |
July 11 (projected) |
* DD = Degree days at base 50°F.
Note: Projections are based on 30-year historical degree day data.
Zone
map – A list of counties comprising each zone and a statewide zone map appeared
in the April 18 edition
of the Landscape Alert.
Howard Russell
MSU Diagnostic Services
Apparently the week of June 22 is “Cool Bug Week” because we got some dandies in the lab. Jeanne (don’t know her last name) sent me a great photo of a Cecropia moth that she was trying to identify. The Cecropia moth is one of our most spectacular moths. The larvae feed on various broadleaf trees and shrubs. The caterpillar is equally, if not more impressive.
I got a call from a concerned citizen saying he found Asian
longhorned beetles up by Ludington last weekend, which made me think that our
native Whitespotted pine sawyer, Monochamus
scutellatus beetles have emerged. And sure enough, we got a very nice
specimen from Norm Myers, the CED up in
Pine sawyers (Monochamus
spp.) are the most common “I-think-I-found-an-Asian-longhorned-beetle” that
are sent into the lab and for good reason, the resemblance is striking. See
photos of the Asian
longhorned beetle to see what I mean. The Asian longhorned beetle is a
highly destructive exotic insect that has been in
The genus Monochamus
is represented by several wood-boring beetle species in the eastern
Two years are required to complete the life cycle in the
Norm also sent us an eyed click beetle or eyed elator, Alaus oculatus. This is another very handsome beetle and is our largest member of the click beetle family, Elateridae. Its common name comes from the two large eye-spots on the pronotum. The larvae, which may reach nearly two inches in length, live in moist, decayed wood, especially stumps. The larvae are predaceous on other insects. These handsome beetles are harmless.
Howard Russell
MSU Diagnostic Services
Sandy Heng, a homeowner in
Carpenter bees resemble our large yellow and black
bumblebees, but they differ in the amount of hair they have on the top of the
abdomen. The top of the abdomen of carpenter bees is bare and , whereas the
abdomen of bumblebees is covered with black and yellow hairs. Other species of
carpenter bees may be black, green or somewhat purplish with various markings
of whitish, yellowish, or reddish hairs, and may be considerably smaller. As
Carpenter bees can be controlled by applying a registered insecticide to the gallery opening. If only one or two gallery openings are involved, then an aerosol bee and wasp spray should be enough to kill off the bees. If large areas are affected then a persistent insecticide can be used to treat the entire area. Painting or otherwise sealing the wood is reported to discourage the bees from chewing their holes.
Howard Russell
MSU Diagnostic Services
In the May 9 issue of the Landscape Alert, I reported the Dr. Jim
Zablotny, the USDA/APHIS/PPQ Insect Identifier at the Detroit Metro Airport,
identified a new state record for Michigan: the elm flea weevil, Orchestes alni (Coleoptera: Curculionidae). Apparently, this bug has
been in the state for a number of years, because I have received several
reports of severe feeding injury due to this pest in the past week. Terry
McLean, Consumer Horticulture Educator in
We are very interested in knowing where else in
MSU Diagnostic Services
101 Center for
Tel 517-355-4536
Howard Russell
MSU Diagnostic Services
We received samples of gypsy moth caterpillars from
Howard Russell
MSU Diagnostic Services
We received a small sample of ‘Blue Star’ juniper that was loaded (possibly a lab record) with Juniper scale, Carulaspis juniperi. There were crawlers walking about all over the needles. Now is time to apply insecticide sprays aimed at the crawler stage.
Juniper scale is a very common and sometimes serious pest of
Juniper in the eastern
The scale insects overwinter as nearly full-grown individuals and mature in the spring. Under her scale covering, the female lays eggs in the spring. She dies soon after egg laying, but the scale cover remains attached to the needle, often for several years. The crawlers (immature scales) hatch from the eggs, usually in June and leave the scale cover to search for a place to feed. The crawler stage may last for as short as 24 hours and after finding a feeding site the small, straw-colored crawler attaches itself to a needle and begins to feed. Soon it develops a coat of armor (the scale covering). The immature scales continue to feed and grow during the summer, and during this growing period the skin is shed several times. The shed skins make up the hard protective cover for the scale insect. By late fall, the scales are nearly full grown and ready to overwinter. The cycle is repeated year after year.
Howard Russell
MSU Diagnostic Services
Oh my word!
Rebecca Finneran
MSUE horticulture educator
I’m not sure if I have ever tried to pick a peck of pickled peppers, but I’ll bet Peter Piper never even heard of an “ornamental” pepper. If he could pick some now, there would be more than a peck of cultivars to choose from!
In an effort dating back 25 years, plant breeders started
making strides towards producing peppers with fruits that are just as pleasing
to the eye as to the palate. Breeding and testing a new cultivar that
eventually makes it to our home gardens can take as many as 15 years. In the
past two or three gardening seasons, the results have started to show up in
garden centers and botanic gardens around the country according to Robert
Griesbach, Research Geneticist of the Agricultural Research Service in
Ornamental peppers really made their claim to fame at the turn of the century, long before the poinsettia became popular as an indoor holiday plant, says Griesbach. Potted, brilliantly colored “Christmas peppers” were very popular because they could take the cool, indoor home environment and yet last a long time.
From a gardener’s standpoint, ornamental peppers are one of the most fruitful annuals one could plant, no pun intended. With little or no dead-heading, the peppers not only last, but get better looking on the plant throughout the season. Many of the cultivars chosen for superior ornamental quality have an intensely colored bloom which is followed by heavy fruit production. The fruits are often cone or cigar shaped like the traditional chili pepper but can also be round or even lumpy, like a miniature bell pepper.
The interesting thing is that as the fruit develops it slowly ripens, magically transforming as the color deepens. For instance, the Kent / MSU Extension office had a display last summer of a dwarf pepper with variegated leaves known as “Shu”. This tiny pepper plant produced one-inch fruits that began a pale yellow then transformed to purple and eventually brilliant red. Throughout the season, the plants were continually covered with peppers at all stages of ripening. With adequate fertility and a bit of supplemental water, these plants were both ornamental and somewhat entertaining. Once established in a container or the garden, pepper plants seem to take all kinds of abuse such as scorching hot sun.
At the Chicago Botanic Gardens in the summer of 2007, a display of a deep purple pepper known as ‘Masquerade’ was complimented by the purple foliage of ornamental basil and the brilliant, and also heat tolerant blooms of Gazania. Another cultivar, ‘Chilly-Chili’ has uniform, brightly colored peppers similar in size and shape to a chili. It produces heavy loads of the showy fruits in the center of the plant and never gets too tall. This plant is excellent used as a border, (did I mention color?) in combination with other bright colored annuals or in containers. By the end of the season, most of the subtle yellow peppers will have turned a brilliant scarlet. I love the idea of not needing dead-heading.
The 2006 All American Selection (AAS) winner ‘Black Pearl’
is the latest eye-catching cultivar to be developed and released by the ARS. To
receive the AAS award, a cultivar must show “superior garden performance.” I
can attest to the outstanding performance of ‘Black Pearl’, which became a
pirate’s treasure in our
If the names ‘Tangerine Dream’, ‘Holiday Flame’ or ‘Red Misssile’ sound intriguing, you can look forward to yet another peck of ornamental peppers landing in a garden center near you in the next few years. According to Griesbach, the future for development and release of new ornamental peppers looks bright. Plant breeding to him is kind of like assembling a Mr. Potato Head doll. He looks for outstanding fruit, to combine with cool foliage and interesting habit. This next season, Griesbach says we can look forward to a ground cover pepper with black foliage. If it is anything like the ‘Black Pearl,’ I could quickly become a pirate gardener!
Vera Bitsch
Agricultural, Food, and Resource Economics
In January
Temporary visitors to
According to a fact sheet issued by the Secretary of State,
applicants for an original
To read Dr. Bitsch’s complete newsletter go to her website at http://www.msu.edu/user/bitsch. Under “News” click on “Update of Michigan Driver’s License Requirements” or click on “Agricultural Labor Issues in Michigan” for a list of available newsletters. Please remember that these newsletters serve educational purposes only and do not constitute legal advice.
Aaron Pollyea
Geography
Shortwave troughs will be the major effect on the state’s weather over the next few days, producing rainfall across the state. The low should enter our region by today, June 27, producing the previously mentioned possible severe weather and rainfall. Rainfall amounts could be more than an inch in northern lower Michigan by the evening of Saturday, June 28, with more limited rainfall extending across the entire state. The majority of the rainfall should persist until Sunday when it will taper off through Tuesday. The warmer temperatures we will be experiencing starting today should persist until Sunday, when cooler weather should occur across the state.
Temperatures during the next few days will be generally steady, with highs Friday generally ranging from the mid- to upper 70s north to the mid- to upper 80s south and lows from the upper 50s to low 60s north to the mid- to upper 60s south. With the shortwave troughs and general cooling occurring, temperatures begin to slide on Saturday ranging from low to upper 70s across the state and on Sunday mid 60s to upper 70s. Temperatures then remain in the 70s across the state until Wednesday when they rise into the mid- 70s in the north and low 80s in the south.
In the medium range forecast, the upper air pattern
mentioned above is expected to continue for much of the remainder of June. The
National Weather Service 6‑10 day
outlook covering July 2 through July 6 calls for below normal temperatures in
the
Further ahead, it is interesting to note that forecast
guidance is also hinting that the very turbulent, active upper air pattern of
late May and early June may return to the upper