May 15, 2020

For the past two weeks my woods have been aglow with the bright white flowers of the blackhaw viburnum. (Viburnum prunifolium)

blackhaw at the woods edge

blackhaws in bloom in the understory

red admiral butterfly nectaring in blackhaw flowers

This shrub or small tree toler...

June 15, 2015

RIGHT NOW is the time of year that emerald ash borer (EAB) adults are active. Here are some photos I took last Wednesday in Willow Grove, Bucks County, PA.

This ash tree had some live branches on it a few weeks ago. Landscape maintenance people have cut and removed them...

May 28, 2014

Lots of local news coverage on the impending invasion of the emerald ash borer has many owners of ash trees alert for any unusual symptoms. So I was not surprised by the number of recent calls I’ve been getting about blighted ash leaves. Leaf drop in mid May is a commo...

January 30, 2014

An exciting opportunity presented itself to me through my membership on the Lower Frederick Township park board. In 2011 the board had been discussing uses for the one of the areas of vacant land that had been acquired using Montgomery County Open space funding.  “Cudd...

June 21, 2012

These pin oaks are shedding leaves, and large parts of some of them have leaves that look white from the ground.  The culprit is scarlet oak sawfly larvae.

I have never seen damage quite like this from this insect.  It’s unusual for it to reach such a high population th...

October 5, 2011

Renee wanted me to help her get rid of the hornets. So I had to decide how to go about it. The most effective way to control European hornets would be to destroy their nest and colony. But we have no idea where the nest is – probably not even on her property. If we wen...

September 29, 2011

These are European hornets.


I never really thought of them as tree pests before. When I see them on trees, usually they’re feeding on sugar that’s been excreted by aphids or scale insects, or on the alcoholic wetwood flux  oozing from a mulberry or a dying elm. But I m...

August 8, 2011

On Monday I checked on an ash tree for a client in East Greenville.  She said the leaves appeared to be wilting.

Well, they didn't really look wilted to me, but they were distorted and curled.


I unrolled some of them to check for pests; none were there.  No aphids, no s...

August 8, 2011

Mrs. B from Royersford called yesterday concerned about her douglas fir trees. She told me one was turning brown at the top, and also the white spruces didn’t look so good. She reminded me that I had sprayed them to control a disease problem a few years ago and was won...