Affliction Afoot

Affliction Afoot

Current Conditions

Weather for the beginning of June has actually been quite pleasant and mild, with some hot and humid days thrown in for good measure. Although the average across the region has been moderate with a little less than an inch of accumulated precipitation, some areas experienced unsettled weather including some strong thunderstorms. Soils in areas exposed to full sun may have dried out a bit, but lawns in parts of region which received rainfall are thriving and green.   The continuing gradually warming temperatures have allowed for extended bloom periods and are now forcing some stubborn woody and herbaceous plants into bloom. On average 439 growing degree days have been added so far this season, and the soil temperatures have reached an average of 67 degrees. Of course as the growing season continues so do the potential problems, diseases have developed or are presenting in new life cycle stages. Discussed below are several currently being reported as active, this is, by no means, a complete list so make sure to contact your arborist with any questions, concerns or treatment needs.

Disease Dilemmas

Plant diseases may have many life cycle stages and multiple hosts so they may present differently in the late spring or early summer as air and soil temperatures rise and days grow longer and sunnier.  These complex life cycles, morphological stages and multiple hosts can  make identification and treatment tricky. Discussed below are some diseases which currently active. Your arborist will be able to properly assess disease on your landscape and recommend treatments and/or preventative measures.

cedar rust

Fruiting bodies for cedar apple rust, cedar serviceberry rust and cedar quince rust are now appearing on cedar trees. Significant branch dieback is occurring as well. Alternate hosts will have foliar lesions.

phomphosis on elm

Cankers caused by Phomopsis may now be quite visible on American elm trees. They appear as large wet patches in crotches of trunk and branch junctions.

fir rust

Needle rust on fir trees has been reported as being currently active now. Yellow lesions will be visible on localized portions of the tree, usually on last year’s needles. The underside of affected needles will have orange blisters which may or may not have ruptured already.


Hemlocks which are already stressed due to woolly adelgid infestation may be especially susceptible to needlecast. This disease may often be found on hemlocks but is usually a very minor issue on healthy trees. Affected trees will display burned looking needles and eventually needle drop.