IN THIS ISSUE:
First Issue for 2014
This is the first issue of the University of Illinois Extension Home, Yard, and Garden Pest Newsletter for 2014. It is written to keep professional landscapers, arborists, golf course superintendents, lawn care personnel, and garden center operators up-to-date on the commercial management of diseases, weeds, insects, and other pests.
New ICLT Available
The 2014 issue of the Illinois Commercial Landscape and Turfgrass Pest Management Handbook is available at the University of Illinois’ PubsPlus web site.
The extended snow cover and cold weather during the winter has resulted in severe rabbit feeding damage to shrubs and small trees. Eastern cottontail is the primary rabbit species in Illinois. They are active through the winter primarily feeding on leafy vegetation from the previous summer.
Meadow voles eat runways through turf and strip bark off of trees and shrubs below the snow during the winter. These field mice are larger than house mice with broad heads and short tails. Last winter with its lingering snow cover was ideal for voles to live and feed under the snow with little predator impact.
Spruce Spider Mite
Conifer feeding mites including spruce spidermite, arborvitae mite, juniper mite, and pine mite are active at this time of year. They should be feeding with this year’s late spring through late April in southern Illinois, mid-May in central Illinois, and late May in northern Illinois.
Have Patience With Plants Injured During the Winter
Welcoming spring temperatures have finally arrived and allowed us to return to our gardens and landscapes. Even with onset of the nice weather, the harsh conditions of the past winter are still fresh in our memories. One of the major concerns we have entering the growing season is how the harsh winter may have affected the plants in our landscapes.
2014 Season at the University of Illinois Plant Clinic
Samples have been steadily appearing this spring here at the Clinic in our 39th year of operation. On the field front, there have been concerns with virus disease diagnosis in wheat. On the home landscape front, there is a mountain of winter kill and windburn injury from the harsh winter just past.
Boxwood Winter Injury
Boxwood plants are susceptible to winter injury in central and northern Illinois when warm winter days are followed by freezing temperatures. The warm days deceive the plant into breaking dormancy and taking up water. Then when the sun goes down, the temperature drops, and that causes the water in the leaf tissue to freeze. The expanding ice within the plant splits and kills cells.
Prostrate Knotweed — A Harbinger of Spring
Prostrate knotweed (Polygonum aviculare) is one of the first summer (warm season) annual weeds to germinate, first appearing when soil temperatures are only in the 40’s. For this reason, I know that spring has arrived when I see it emerge.
Modified Growing Degree Days (Base 50°F, March 1 through April 24)
Insect development is temperature dependent. We can use degree days to help predict insect emergence and activity. In warm years, insects emerge earlier, like we experienced last spring. Degree day accumulations are slightly behind the 11-year average.
Illinois Invasive Species Awareness Month
As we near the end of April we are getting ready to embark on another Illinois Invasive Species Awareness Month (ISAM) beginning in May. Central to this year’s events is the theme that “Invasive Species Affect Everyone!” If you live in Illinois, work in Illinois, recreate in Illinois, or just simply breathe in Illinois, invasive species affect you!