Almstead Arborist, Gary Norman, Preserving Trees in Greenwich

One of our arborists, Gary Norman, was recently featured in the Greenwich Daily Voice for his work in preserving trees in Greenwich. Three 150-year-old trees planted in front of Greenwich Academy are among the ones he has worked to protect and preserve.

 “It’s rewarding to have the opportunity to keep historic trees in good health by protecting them from pressures such as disease, microclimate change and construction,” says Gary.

In fact, it’s not just large construction projects that can damage trees – home construction can be deadly as well. Fortunately, the majority of construction damage can be mitigated with the guidance of a qualified arborist along with the full involvement and cooperation of all parties involved in the project: from architects to subcontractors to landscapers. The process begins with identifying the trees to be preserved. Next, we try to protect the tree from the construction process. This includes making sure the tree is well fertilized, watered and mulched and protected by fencing. We try to minimize the compaction of soil over the tree roots – ideally the fence includes the entire root zone. If it is necessary to cut the roots, an arborist can usually sever them with far less impact to the tree than a contractor.

New grading and drainage can leave this tree thirsty.

Gary, like all our Almstead arborists, has had a lot of experience with this process. “Most people are aware of the most obvious effects of construction, like damaging the tree trunk or compacting the soil,” he notes. “But there are other effects that are more subtle. For example, cutting down surrounding trees can leave a tree suddenly exposed to sunlight and wind – conditions that some trees can’t thrive in. Another problem is changing the grading or drainage: these improvements can literally leave a tree high and dry, without enough water to nourish it.”

We all need to adapt to change at times, including trees. Conscientious care from an Almstead arborist can help these trees have the best chance for survival.

Unwanted Landscape Pest #10: Birch Leafminer

Today we're starting a series on America's Most Unwanted -- or really the NY/NJ/CT region's Most Unwanted -- Landscape Pests. So we've selected Almstead's top 10 unloved insects that plague our landscapes. Some of them are killers (of trees or shrubs), while others just turn a beautiful planting into a shredded mess.

The countdown begins with the Birch Leafminer. This is an insect with narrow dietary preferences: Birch trees, particularly Paper Birch, Grey Birch and European White Birch. The Birch Leafminer is a European import; unfortunately its natural predators didn't come across the sea with it. In some areas of the U.S., the European wasps are being released to help keep the Birch Leafminer population under control.

In its adult form, the Birch Leafminer is a sawfly -- but it is the larvae that really wreak havoc on the Birch leaves. These hungry little Leafminers actually insinuate themselves between the top and bottom of leaves where they munch their way along a serpentine path. As these paths intersect, large portions of the leaves start to turn brown.

Birch Leafminer Damage
Source: Whitney Cranshaw, Colorado State University, Bugwood.org 

You'll typically notice Leafminer activity in the tops of Birch trees -- since the Leafminer mothers choose the tenderest new leaves as the best place for their larvae to survive. Whole sections can turn brown due to Leafminer activity. Though the brown leaves are unsightly, and won't regrow during the same season, Birch Leafminers are not generally tree killers. However, if an infestation repeats itself over several years, the cumulative damage can be too much for the tree to survive.

By the time you are aware of Leafminer activity, it is usually too late to alleviate the damage for the season. As part of an Integrated Pest Management approach, our Almstead arborists  recommend early application of controls to prevent the larvae from emerging in the next season.

Integrated Pest Management Explained

We sometimes take it for granted that everyone understands what Integrated Pest Management means. It is one of the cornerstones of our tree, plant and lawn health care programs. But, since many of our clients have questions about the practice, let me give you a little more information.

Decades ago, when synthetic pesticides were developed, they were used liberally. And they were effective at killing pests – but they killed many beneficial insects as well. This means that the natural balance in the area where they were used was severely disrupted. The whole food chain was interrupted, and often the birds disappeared along with the bugs.

The concept of Integrated Pest Management (IPM) arose from a desire to work within the natural order. So, rather than saying "We’re just going to eliminate all aphids",  we ask the question, “Are these aphids being controlled by their natural predators, like lady bugs and praying mantises?”  Or “Are there certain plants that need to be protected, because they are particularly vulnerable to aphids?” If the aphids are growing out of harmony with their natural predators – perhaps on an especially alluring rosebush -- we step in with a very targeted treatment to manage their population, either by killing the adults, or more likely, preventing the larvae from emerging. So rather than indiscriminately spraying insecticide all around a garden, we will apply horticultural oil (to prevent the emergence of larvae) to the aphid-loving rosebush.

Integrated Pest Management isn’t always organic – but increasingly, we find that natural or bio-rational products are best for these narrow-focused targets.  And we’re always exploring organic options wherever possible.

So how do we know what to use and when? One of the fundamentals of Integrated Pest Management is inspection.  Our technicians go out and inspect our clients’ properties several times a year, and then use products that specifically respond to any observed insect or fungal threats.

An Almstead arborist shows a client how we inspect plants.

And managing insects through applications is just one tool for keeping plantings healthy and beautiful. We can also limit the spread of insects or diseases through selective pruning of infested branches as well as by improving the overall health of plants (and their resistance to pests) by improving the soil. 

Ken Almstead - CEO, Arborist

Tree Neural Networks -- Think Avatar ......

If you saw the movie Avatar (and apparently, most of us did), you saw how the planet Pandora was composed of a gigantic neural network. Life, health, knowledge, strength -- everything could flow through these connections from one tree to another, and to the other living creatures that could tie into the network.

This shows root graft between two Oaks. Oak Wilt is
easily transmitted this way.

So often, science fiction is based in reality. Trees unquestionably maintain a network beneath the ground. As an arborist, you ignore that network at your peril -- because diseases can be transmitted from one tree to another through root grafts. Trees of the same species are often able to connect their roots and establish a back and forth flow of nutrients and fluid -- and some potentially deadly stuff as well. Which is why, when we consider how likely a diseased tree is to infect others, we need to think of the connections below the soil as well as well as more obvious methods of transmission (like insects). Dutch Elm Disease is a prime example. If there are nearby trees of  the same species, we try to sever those root connections by removing the diseased tree, roots and all. Then we inoculate the remaining trees and hope we got there in time.

There is more and more evidence that these neural networks allow trees to work cooperatively. If a tree is stronger and better situated -- perhaps where water is more available -- it can actually send fluids over to its thirstier cousin. And the same seems true for nutrients and beneficial fungi. "A little more phosphorus over here, please."

Here's a link to an interesting video made by Professor Suzanne Simard of the University of British Columbia. She suggests that these underground connections are sophisticated enough to be actually called communication. 

Suzanne Simard video

- Michael Almstead, VP and arborist