No. 5/May 21, 2012
Hatching bagworms were found in the Champaign-Urbana area of central Illinois on May 14. Hatching typically occurs in the first half of June, so they are two to four weeks early. The phenology indicator is catalpa full bloom, which was occurring early this week. We recommend that treatment be delayed for two weeks after hatching to allow ballooning to finish. Hatch would have occurred in southern Illinois about two weeks ago, so it is time to treat in that portion of the state.
Roses Are Red, Canes Are Dead, ...Now What?
We are still seeing the effects of the late frost on plant samples at the plant clinic. In roses, frost can destroy fresh growth and cause stems and leaves to wilt, turn black and fall away from the plant.
Newly emerged yellow nutsedge (Cyperus esculentus) has been spotted around central Illinois recently. Also known as yellow nutgrass, yellow nutsedge is a warm-season perennial member of the Cyperaceae (sedge) family that reproduces by seeds and from tubers (nutlets). Though the sedge family contains 98 to 146 genera and over 5,300 species, the most common weedy sedge found in lawns and landscapes across the state is yellow nutsedge.
Bacterial Leaf Spot on Oakleaf Hydrangea
This weekend, while working in my yard, I noticed my Little Honey wasn't looking too good. Of course, I am referring to my Little Honey Oakleaf Hydrangea. The normal gold to chartreuse leaves had developed numerous dark reddish-purple angular spots. Hydrangeas are known to be hosts to several leaf spots, both fungal and bacterial. Oakleaf Hydrangeas, in particular, are known to develop leaf spots caused by the bacterial pathogen Xanthomonas campestris.