Tree and Shrub Damage
Martha Maletta, Home Horticultural Consultant
Dated - June 02, 2004

I don’t remember ever seeing the damage that is so apparent and prevalent on native cedars (Juniperus virginiana) this spring. Scattered brown twigs that appeared recently throughout the trees seem only attributable to winter damage of some sort. The Rutgers Plant Diagnostics lab agrees. Since there is still plenty of green on affected trees, it does not appear to be a serious situation, just a curious situation.

Some other species or varieties of juniper do appear to have been seriously damaged, if not killed, this winter. Winter damage, salt damage, rodent damage are all possibilities. Check, also, for evidence of bagworm on brown junipers. It’s not easy to miss the bags suspended from ends of brown or bare branches that contain the eggs for this year’s generation of these destructive caterpillars. Infested plants can be sprayed soon. Contact the Rutgers Maser Gardener Helpline of Hunterdon County at 908-788-1735, M-Th, 9 a.m. to noon and Th 12:30 to 3:30 p.m. for a copy of Rutgers current control recommendations.

A couple of weeks ago the first samples of four-lined plant bug damage arrived in the Rutgers Master Gardener Helpline office. The fast moving reddish nymphs of this small yellow and black striped bug had already been busy feeding on some perennials, leaving behind the telltale brown spots that could be mistaken for disease. Leaves, especially younger ones, can be distorted and blighted when enough feeding spots are present. Four-lined plant bug has a very large host range that includes shrubs as well as herbaceous perennials. This pest is not easy to control, so it is good news that there is only one generation per year and plants, if otherwise healthy and vigorous, will out grow the damage.

Periodical cicadas are here, but where are they in Hunterdon County? Let RCE Hunterdon know about locations so we can notify Dr. George Hamilton, RCE Specialist in Pest Management, for purposes of mapping emergence sites in New Jersey. He is helping Dr. Chris Simon, U of Connecticut, a leading researcher on periodical cicadas, and has requested help from county RCE offices and local residents. Call the Master Gardener Helpline to report sites.

You may have noticed that the “gnats”, which plagued Hunterdon County and several other NJ counties in years past, are back. The control program that had been in place, a joint effort of NJ and PA in treating the Delaware River that is the most important source of these black flies, was discontinued last year when NJ funding was cut. Residents who experience a serious black fly problem should let their State legislators know about it.

Dr. David Drake will be talking about some larger pests on Friday, June 11, 10a.m.-12 noon at the Melda C. Snyder Teaching Garden of the Rutgers Snyder Research and Extension Farm. Learn from the RCE Wildlife Specialist about “Managing Wildlife in the Home Landscape”. Please call 908-526-6293 if you plan to attend.

Saturday, June 12 will be Rose Day at the Rudolf W. van der Goot Rose Garden in Colonial Park, East Millstone, NJ. From 10 a.m. to 4 p.m. the collection of more than 3000 roses will be open, there will be a variety of lectures and rose experts will be available for questions. This event is free. Also at Colonial Park, on Saturday, June 19, 9 to 11 a.m. there will be a two-hour field study of “Summer Color in the Perennial Garden”. Registration is $10.00 and space is limited. Call 732-873-2459 to register or for more details about either of these events.