Emerald Ash Borer Update

Emerald Ash Borer feeding galleries

Last year at this time, we were consumed with figuring out how to deal with the reality that Emerald Ash Borer had been detected in Bucks County. A year later, this pest seems to have faded away. Not so!

While no additional detections beyond the original site in Warrington have been noted, the bug has not disappeared. There were many ash trees infested at this site and no doubt the adults that emerged from those trees flew off to mate and infest other trees. Studies of previously infested sites indicate that the infestation will move about ½ to one mile per year, even when attempts to eradicate the insect are in force. In addition, the infestation in Warrington is estimated to be several years old. So…..I figure EAB is most likely already established a few miles from Warrington, it just hasn’t been detected yet.

Still, the good news is that folks who fall outside of a 10-15 mile radius of Warrington can wait and watch. Researchers say that treating trees beyond this is a waste of money. This “lull” period provides time for people and communities to make a plan for the day when EAB arrives. It’s a question of when, not if, and that’s an important fact. There is no doubt that ash in Buck County will be killed when this insect reaches them.

For a refresher on Emerald Ash Borer, see this site.

On Thursday May 9, The Pennsylvania Horticulture Society will conduct and Emerald Ash Borer workshop at Neshaminy Manor Center for municipal, private and community professionals who are planning for the impacts of EAB. Contact PHS to register. Pre-registration is required.

Downy Mildew of Impatiens

flickr.com/photos/aquariawintersoul/4989557445/

Many gardeners have come to rely on the common impatiens (Impatiens walleriana ) to brighten shady garden areas. Shady areas are a challenge for any plant, so finding one that tolerates shade and produces mounds of red, pink, lavender, orange and white flowers makes this plant a favorite for many gardeners. Now, because of a disease called Downy Mildew, a wise gardener will look to other species to fill those shady garden spots.

Photo credit: Laura Sanagorski University of Florida

Experiences in the past two years have shown how devastating downy mildew disease is to impatiens. It can totally defoliate plants in a matter of days, leaving behind just stems. The most diagnostic symptom is a white mold on the underside of leaves. Cool, moist weather is ideal for infection and spread of the disease. Places where impatiens were injured last year are especially likely to be a problem because the organism that causes the disease can survive the winter and infect new plants. Fortunately, this disease organism does not affect other landscape plants.

So, what can a gardener do? Plant something else.

There is no sense in trying to control this disease in the landscape. There are effective fungicides but they require frequent application combined with precise timing. There are no good cultural or biological controls. There is no known resistance in common garden impatiens.

New Guinea impatiens (Impatiens hawkerii) are resistant to downy mildew and make a good substitute. They can cost more but are a good choice. Sunpatiens, relatively new hybrids of several impatiens species, are both sun and shade tolerant and are not injured by downy mildew. Sunpatiens come in several size classes but even the most compact forms are much taller than common impatiens, so plan accordingly. Begonias, Torinia, Coleus, Lobelia and other annuals are also good alternatives for shade. Ball Seed company has a nice publication that provides even more choices. Granted, nothing will completely replace the fine qualities of common impatiens.

The greenhouse industry has taken Impatiens Downy Mildew very seriously. Growers will still produce common impatiens for those who want to risk losing them to disease. At the same time, they’ve ramped up production of good alternatives and are informing professional landscape managers and consumers about the sad realities of this new disease.

Want more information on Impatiens Downy Mildew? Dr. Mary Hausbeck, plant pathologist at Michigan State University has a good question and answer publication on the subject.

Wood Heat.... Go Wood!



Mini Holzhausen

 Is there anything more pleasant than sitting by a warm, wood fire? Not much, in my book. The pleasure grows if you cut and split the wood yourself. As they say… in this manner the wood heats you twice. First, while working up a sweat splitting it ! Next, when you burn it. The whole process is very satisfying.


Wood heat can be economical as well. A cord of ash or oak has about the equivalent heating value of a ton of hard coal, 130 gallons of fuel oil or 3500 kilowatt hours of electricity. You do the math. Ok, I’ll do some…if fuel oil is selling at $3.50 a gallon, I think I can pay $455 for a cord of dry hardwood such as ash or oak (130 x $3.50 = $455). Currently, you can buy wood by the cord for about half this price. If you have a chainsaw and pickup truck you’ll find wood readily for free. That big storm Sandy was a windfall for some of us… literally. These figures assume you are burning that wood in a reasonably efficient wood stove, not a fireplace.

Of course, tending a wood stove is different from turning a thermostat. Not to mention the need for a wood storage area, hauling ashes, the centralized nature of heat from a wood stove, hitchhiking bugs, cold mornings, etc, etc, etc. I admit it’s not for everyone. On the other hand, it’s hard to get a real romantic feeling from a radiator. At least it is for me.

There is an awful lot to learn if burning wood is a new venture for you. Safety is a major issue. Proper stove installation and venting is critical. Oh, I forgot to mention, the chimney for your new wood burner may cost more than the stove…..yea, I guess we’d better figure in the infrastructure costs of burning wood… not just the fuel itself. Somewhere in my files I have a humorous piece that pokes fun at all of the hidden costs of burning wood. Conclusion is that it can’t pay!

On the other hand, maybe you are lucky and have some of these elements in place, left behind or second hand. That helps a lot. In any event, be sure to make safety first. None of this is worth it if you burn down the house.

Cornell University has an excellent wood heat site. And Heating with Wood and Coal from Northeast Cooperative Extension is a very comprehensive publication on the subject.

Finally, as I poked around on the web I came across a fantastic blog on wood call GoWood. Where? At Penn State! Written by Chuck Ray, Associate Professor of Wood Operations Research at Penn State, this site looks at many aspects of wood uses. Makes sense. We are in Penn’s Woods, after all. Chuck is a prolific blogger and brings many interesting facts and insights to the subject of wood. Lots of cool video links. Old and new.

I stumbled on Chuck’s blog as I was poking around the internet, trying to figure out a way to speed up wood drying. Remember that windfall from Super Storm Sandy? Yep, I have a lot of wood that is not dry enough to burn and I want to accelerate the process. Chuck, too. We both ended up exploring holzhausens. Wood houses, in German. All I can say is… check it out. Above is a picture of my first attempt at making a holzhausen. It's only 6 feet in diameter and about 5 feet tall. Time will tell how well it dries wood. I don’t care anymore; it’s the best lawn ornament I have. Chuck’s blog has a link to the best video I found on holzhausen construction as well as some amazing work of wood art form around the world. Go Wood!

Scarlet Oak Sawfly

skeletonized oak leaf

“What’s up with the oaks?” or “Are my oak trees are dying?” were common questions from residents in the Hilltown/Perkasie/Bedminster area this year. Symptoms included whitening in the tops of pin oaks and, on closer examination, leaves that had been “skeletonized”. This means that all of the soft parts of the plant tissue were gone but the “bones’ remained… just the skeleton.


You might think, as I did originally, that the insect called Oak Leaf Skeletonizer was the culprit. But a conversation with Penn State entomologist Greg Hoover led to the conclusion that this was another insect, Scarlet Oak Sawfly. Both insects skeletonize leaves but Scarlet Oak Sawfly does not leave tell-tale pupal cases on the leaves as does the Oak Leaf Skeletonizer.



pin oak injury from sawfly feeding

 The clincher was speaking with arborists Craig Brooks (Bedminster) and Bob McMullin (Doylestown). Both reported diagnosing the problem in the past two years. Craig and Bob are International Society of Arboriculture (ISA) certified arborists and excellent tree men. If you are looking of tree care, an ISA certified arborist is a really good idea.

So, what will become of oaks infested with Scarlet oak sawfly? PSU’s Greg Hoover thinks that natural predators and parasites will begin to take control and reduce sawfly populations to levels that are almost harmless. Defoliation is the issue here. The question is: “How much foliage can a tree stand to lose?” Answer is: "Some, not too much, not too often." It is not a black and white situation. Many factors such as overall tree condition, amount of foliage loss and site factors come in to play. It is unlikely that partial defoliation in one year will be a life or death situation for an oak.



sawfly larva feeding

 However, major defoliation in consecutive years is a problem. Think about gypsy moth damage. Similar scenario here. Except that Scarlet oak sawfly has two generations, one in early summer and one in late summer. Insecticide options exist, but the bugs habit of feeding from the tops of trees downward can present logistical problems... how to get good spray coverage at the top of a 50 foot tree? If necessary, arborists have the tools to do the job. It is not a do-it-yourself situation.

Personally, I have my bet on Mother Nature to come to the rescue. Sure, She can be unpredictable and is habitually late, but population spikes of one bug eventually result in their enemies coming along to even things out. 

Fresh From Bucks County Farms

Summer has arrived … and so have seasonal fruit and vegetables. Blueberries are “in” and peaches are not far behind. Raspberries are about to ripen. Get them while you can! The first tomatoes, planted early in greenhouses, are about to become plentiful, too. Some local sweet corn for the 4th of July? You bet.



"New" potatoes and peas

You can find a source for all of these favorite produce items in the 2012 edition of Fresh From Bucks County Farms, a directory of local farms, farm markets and CSA’s published by Penn State Extension. Copies are available on request by calling 215-345-3283 or at this site. Copies are also available in any Bucks County library.


While peaches, sweet corn and tomatoes get all of the attention, there is a lot more to like in the local food scene. “Foodies” have been enjoying garlic scapes for the last 3 weeks. The strawberry crop was exceptionally early and delicious this year. If you have never enjoyed “new” potatoes and peas a visit to the local farmers market will introduce you to a June treat.

Looking of something special? European-style artisanal cheese? Champagne? Duck eggs? Lamb? Grass-fed beef? You will find it all in Fresh From Bucks County Farms.

Start Farming

High tunnel greenhouses extend the farming season

This is a gardening blog so you might think farming is not up your alley. But as gardeners, you have a lot in common with farmers. You watch the weather more closely than most people. You have an intimate relationship with insects… some friendly, some adversarial. You grow more of your own food than most folks. You know the names of beet varieties… because you grow them.


And I’ll bet that some of you have farming fantasies. You can see yourself selling stuff at the local farmers market rather than buying. You stare at tractors, longingly. The smell of manure is like perfume. As you might suspect, you are in a minority. So are farmers. Census data says that about one percent of the U.S. population identifies its occupation as farming. And that group is aging. About 40 percent are over 55. There is legitimate concern about where the next generation of farmers will come from.

What’s Penn State got to do with it? Well, as many of you know, we’ve been in the farming education business since about 1862. Many of today’s farmers were not born on farms. They followed a dream of farming and made it a reality. I can quickly name a Bucks County dairy farmer who grew up in Philadelphia, a vegetable grower who was an electrician and a commercial fruit producer who is a nurse. Each of them would tell you that Penn State has played a role in their success.

Recently, a federal grant was initiated specifically to help beginning farmers get started. Tianna Dupont, Penn State Extension Educator, is heading up the Start Farming program in Southeastern Pennsylvania. In the last two years, this program has reached more than 950 new and beginning farmers through 36 courses with names such as: ABCs of Beekeeping, Exploring the Small Farm Dream, Pasture School, Sheep Short Course, Introduction to Organic Vegetable Production and Small Scale Poultry. About half of the participants had no farm background or farming experience prior to taking the courses. These courses are ideal for working people, those between jobs, folks nearing retirement, and others who cannot devote time to full-time undergraduate course work, but still want to receive high quality education in agriculture.

For those who are ready to take on four years of study, Penn State has about 20 majors in agriculture. And they are popular! From the years 20005 to 2010, College of Ag enrollment at Penn State was up 42 percent. To see what the curriculum in agriculture looks like at Penn State see this.

It is interesting that at a time when concerns about where the next generation of farmers will come from, enthusiasm for food production is sky high….from both consumers and prospective producers. Want to start farming? See what Penn State has to offer.

Yes, Kiss Your Ash Goodbye

Emerald Ash Borer larval feeding injury

About nine months ago, this blog described purple traps hung throughout the Delaware Valley which are designed to detect an important pest … Emerald Ash Borer (EAB). The traps were not successful in detecting this insect but a sharp-eyed arborist was. Last Friday I got a call to look at some ash trees that were ravaged by woodpecker feeding. Beneath the bark, signs of larval tunneling were obvious. A few days later, Pennsylvania Department of Agriculture entomologists visited the site and verified that this was indeed Emerald Ash Borer.

Bad news for ash trees.

You can read the blog of June 11 last year and get the story … nothing has changed except that a detection has been made about 100 miles east (Warrington, PA, Bucks County) of the leading edge of the Pennsylvania EAB infestation. About the only good news is that a tremendous amount has been learned about this insect in the last 10 years. See this Penn State site or this National EAB site for solid, research-based information. The PSU “Frequently asked questions” feature is a good starting place.

For tree owners, the time has come to consider the fate of your ash. Depending on who’s counting, this insect has killed between 40 and 50 million trees between Michigan and….. Warrington. It is in 15 states and two Canadian provinces. It’s a tree killer. Infested ash die.

Individual trees can be protected with insecticides. Some can be applied by homeowners but, from what I read, the best product is available to arborists only and has to be injected. Upside? Two years of control.

Another hopeful thought is that entomologists now have several parasitoids, (bug killing bugs) that may provide some control of EAB… and perhaps the site recently detected would be a release site for them. That would be nice. Cross your fingers.

But don’t expect predators to catch up to EAB in Bucks County before a lot of damage is done. For now, learn to recognize ash . Think about whether it is really important to preserve those that you see. It is not practical to treat every ash tree. Remember, treatment provides only temporary protection, not immunity or a cure.

Those considering do-it-yourself treatment will find instructions here

Anyone following the story of Emerald Ash Borer knew that it was only a matter of time before this insect would be found killing ash trees in eastern Pennsylvania. Maybe this knowledge lessened the blow a bit. Also, those who closely observe tree and pest interactions know that this is one of many associations between an insect (or disease pathogen) that results in catastrophic impact on a species. See Dutch Elm Disease, Chestnut Blight or Hemlock Wooly Adelgid. More recently, Thousand Cankers Disease of Black Walnut.

I never paid much attention to ash trees until EAB arrived in Pennsylvania five years ago. Now I see them everywhere. Not for long.