Suffering Sap Suckers?

March 22, 2007

As spring slowly warms up many migratory birds return to their summer territories.

Robins are always seen as a welcome harbinger of spring. One less welcome returnee is the Yellow Bellied Sapsucker. This small member of the woodpecker family can cause big damage to your prized trees. The bird itself is a little larger than a robin and has a bright red cap and white stripes on its head. The balance of its body is black and white with a yellowish tinge to the belly.

This industrious bird has been known to cause damage to a large variety of tree species.

It tends to prefer smooth barked deciduous trees like the linden, aspen and apple, but will frequently attack Scots pine, white pine and other conifers.

The damage caused is very characteristic, small pea sized holes in neat rows horizontally and vertically, sometimes girdling the trunk. These holes fill up with sap and the bird returns periodically to sip up his tasty handy work. Unfortunately the holes injure the tree directly by damaging the vascular system, preventing the flow of sap back down the tree. These holes also allow insects and diseases to enter into the tree and cause further injury.

Sapsuckers are federally protected migratory birds. You can not simply eliminate the problem by eliminating the birds. This would not only be illegal it would create a vacancy in the territory and a new bird will move in and set up shop. If the tree that is being damaged is not particularly valuable you may consider leaving it to the birds and protecting other more valuable trees. Remedies such as applying hardware cloth to the area being excavated or applying tangle foot to the bark to discourage feeding activity, have proven to be effective. Other people tie tinfoil pie pans, blow up owls, or plastic snakes to discourage the Sapsuckers.

If you are growing trees for specimens or timber you may wish to locate the hollow tree the birds are nesting. These birds normally nest in cavities of rotten aspens or other similar, easy to excavate trees. Mark the tree and eliminate it in the winter when the nest is unoccupied. The birds are quite attractive and do frequent suet feeders. If the damage is minor and you can encourage them to feed elsewhere, they can be quite entertaining to watch.

For more information on trees and tree pests contact an ISA Certified Arborist.

The Big Freeze

February 18, 2007

As you look out your window longing for spring take comfort in knowing that your trees are not really frozen. “That’s impossible with the temperature so far below freezing!” you may think. If your trees were frozen in the traditional sense, like your garden tomatoes, they would be dead.

Hardy perennials and trees have three strategies to prevent them from joining their green cousins every fall. An understanding of why your tomatoes are dead will help you realize why your trees are simply dormant.

In the fall when temperatures drop to the freezing point, ice crystals begin to form in the plants cells. While they are pretty to look at in a snow flake, forming inside a living plant cell

the results are devastating. The sharp water crystals puncture the plant cell causing its contents to leak out. The cell dies as a result. What you see is a wet limp leaf or stem that usually turns black. Commercial food production uses a fast or flash freezing to prevent ice crystal formation and keep your vegetables from getting mushy. Trees are by in large composed of water so how can they survive freezing weather?

Trees have several strategies to prevent ice crystal damage. Even the smallest amounts of

dissolved solids in the water in a tree will lower the point at which ice crystals form. This increases the plant’s ability to survive temperatures slightly below freezing. This is the same reason that salty ocean water freezes at a lower temperature than fresh water. In the case of plants, it is the dissolved sugar that prevents the plants from freezing at just below the freezing point of water.

As the temperature decreases the tree must be prepared by moving water out of the exposed plant cells and into areas that don’t freeze, like the roots. This causes the drying of the exposed upper stems and branches as well as concentrating the remaining sugars in the cells to prevent freezing. Much of the moisture remaining in the cells can be shifted to locations just outside the living cell in the intercellular spaces. Once outside the cell there is no danger that water crystallization will damage the cell.

The entire process reverses itself as the weather heats up in spring. Many plants are injured by rapid warming and freezing that can occur in areas that experience extreme changes in temperature. The ability to survive longer unusually warm spells, while not breaking dormancy, is an issue that affects winter hardiness. Plants that bloom or leaf out early in the spring, are more likely to be damaged by spells of unusually warm winter weather. For more information on winter hardiness contact an ISA Certified Arborist.

Bricks in Your Tree

January 14, 2007

The title (of) this month’s article pretty well sums it up. If you had called your tree surgeon as few as 20 years ago you may have ended up with this unlikely remedy. In the past it was standard practice to fill cavities in mature trees with solid materials to “support the tree”. Imagine if you will the surprise of a fellow arborist years later when he cuts into a seemingly solid tree to find it is full of concrete or bricks!

Cavities in trees form when wood dies and decays. Animals and insects will use the weaker rotten wood to form nesting sites or galleries for there colonies. The two most common causes of injury in trees are incorrect pruning and storm injury. Both actions can result in extensive areas of internal decay in otherwise healthy trees. These rotten areas once excavated by animals or insects can be quite large.

It is important to remember two principals when looking at these cavities: a hollow pipe is as strong as a solid rod and the tree has already formed barriers that will limit the spread of further decay. The first principal flies in the face of the thought, you must fill this cavity or the tree will be weak and fail. What really happens when you fill a living dynamic biological system, a tree, with a solid inert mass of concrete is quite predictable. The tree is further damaged by the constant abrasion of the concrete against the inside of the tree. The concrete is also chemically very different than the tree and will increase the moisture level in the cavity. It will also have a caustic injurious effect on the living wood of the tree. The second principle is that trees are living and act to limit the spread of decay in their tissues. Tree cavities are isolated from the living wood tissue in a tree by strong chemical barriers created by the tree when it was originally injured. If you have ever split firewood you will notice a dark staining around old dead branches in the wood. This is the chemical barrier the tree has erected to prevent the rot from spreading from the dead branch to the living tree tissue. These barriers are reinforced and redirected whenever the tree is re-injured. This injury process occurs every time a tree with a filled cavity moves in the wind. This process of creating resistant chemical barriers in wood is very energy expensive for the tree. Trees that do not have the energy to erect or maintain these barriers will be overcome by rot. When this happens the tree will die.

Occasionally trees will develop cavities that fill with water. It is not recommended to drill holes to drain this water as the tree has created barriers to prevent the water and rot from spreading. Drilling holes will further injure the tree and increase the size of the cavity.

So what is the preferred process for dealing with tree cavities? Access the structural strength of the tree. Is it able to stand with the sound tissue that remains? Access the proximity of the tree to potential targets should it fail. Examine the cavity and if necessary remove any loose debris that remains in the cavity with out injuring the living tissue. Monitor the cavity and see if the tree is putting on strong growth around the cavity evidenced by new healthy tissue.

If the tree is not posing an immediate danger to people or structures it may be safe to leave it where it is and continue monitoring it. When in doubt have a Certified Arborist evaluate the condition of the tree and give you an appropriate recommendation.

Christmas Holiday Tree Nuts

December 1, 2006,

This time of year our thoughts turn to the holidays, trees and feasting. While no festive season is complete without the smell of a real home grown tree, tree nuts are also a part of many people’s holiday celebrations. I’m not talking about inviting your arborist over to enjoy holiday cheer, although that’s one way to ensure you will have a certified tree nut in your house!

Almonds, hazelnuts, walnuts and Brazil nuts are the tree nuts associated with this time of year. Although many people enjoy these delicious treats few stop to think of the origins of these delicious treats.

The ancient practice of eating nuts and other fatty foods is tied to the winter solstice festivals of ancient Europe. In the winter days are short and nights are long. Nuts, a food that causes the body to release endorphins, can create a feeling of well being and mirth. In addition nuts increase the amount of serotonin in the brain. In Low serotonin levels in people have been related to despondent, lethargic and irritable behavior. Eating nuts makes you feel happy!

The almonds in your store typically come from California. This fruit of the tree Prunus dulcis,

is known as “sweet almond”. This nut was carried as a ground mixture on the ancient caravan routes between Europe and Asia. Travelers spread this seed from its origins in Mesopotamia to Greece and the entire Mediterranean climate area of Europe. It is a distant relative of stone fruits like peaches and plums.

Hazelnuts typically come from growers in Oregon, although varieties are native to eastern North America right up to the sub arctic. All hazelnuts are from the genus Corylus and are also called filberts. Filberts are native to the higher elevations of the Mediterranean. They are delicious roasted or ground into a flavoring in lamb stews.

Walnuts have been in cultivation for over 8000 years. The Romans referred to walnuts as Jupiter’s royal acorns. The most popular ones we eat are European walnuts grown in California. All walnuts are in the family Jugulans. Locally you can find Jugulans niger, the black walnut. The fruit of this variety is more shell than meat.

The most intriguing nut story goes to the Brazil nut, the nut that a country was named after. Brazil nuts grow only in the intact rain forest of South America. The Brazil nut, Bertholletia excelsa is a major non timber forest product for the peoples of Brazil as well as Peru. These giants of the rain forest can reach 150 feet in height and can be over 800 years old. In the rain forest only one species of bee can pollinate the Brazil nut tree. This bee needs a specific orchid to complete its life cycle. These orchids only row in association with the Brazil nut tree in areas of intact rainforest. The Brazil nuts come in hard pods, harder than the shell of the nut. Only one rodent indigenous to the region can chew through this shell and disperse the seeds. The Brazil nut tree is at the top of this unique ecological web. If one species is missing from this triangle the Brazil nut is doomed.

So if you want to carry on a long holiday tradition, feel good while doing it, and save the rain forest, get a bag of mixed nuts this holiday season. You could invite a certified tree nut to join you, your Arborist.

Old Friends

While walking in a friend’s garden the other day I stepped on a stepping stone with the following inscription; “It takes a long time to grow an old friend”.

Trees are long lived organisms that can easily have life spans across human generations. While not all trees live hundreds of years some can live thousands. Large mature trees are adapted to extreme forest environments and threats. There are many strategies to help trees survive various natural catastrophes. For example fire resistant bark, roots that can regenerate after disasters and seeds that take years to germinate are genetic adaptations for survival. These survival strategies don’t always work for the trees in your front yard.

Changes in nature can be sudden or they can take years. Sudden changes include ice and wind storms that rip and tear branches from trees. Lightning, fires and floods also happen quickly. Long term changes that effect tree survival are soil erosion or deposition, encroachment by grass, and competition for light from other trees.

How does this relate to your front yard trees and their survival?

Simply, change requires adaptation and adaptation in trees is pre programmed. If the tree isn’t able to adapt to changes in it environment it declines and dies. If the tree does not have, within its genetic bag of tricks, the ability to survive fire, the tree will die. A burr oak tree, with thick fire resistant bark, would be able to survive a runaway grass fire without major consequences. A thin barked cherry tree would not survive.

If your tree isn’t able to survive changes in grade or soil compaction it will not survive construction of a new addition to your home.

Trees like American elm will survive changes in grade and soil compaction while white oaks will most likely decline as a result of root disturbance.

In the modern world we are able to affect great changes on our landscapes. Heavy equipment can literally move mountains. Why do we expect trees to survive after the mountain has been moved? Obviously we overestimate the ability of trees to survive construction damage. Trees are alive. Damaging roots has serious impacts on plant health. Tree roots are living plant organs that take moisture and nutrients from the soil environment. The top eight inches of soil contains 90% of all tree roots. Take a look at a storm toppled tree and you will see a broad shallow fan of roots.

So when we think of changing our landscape we should consider the impact that these changes will have on our “Old Friends” before we make the changes. If you’re not well versed in the capabilities of your trees contact your arborist well before construction begins. They will be able to help you minimize the impact of changes in your landscape and maximize the survival of all our green friends.

Dedicated to the Preservation of People

October 29, 2006

It is the small stuff that can kill you. And if it doesn’t kill you it can cost you lots.

Having operated a chain saw for 28 years I may be more at risk of injuring myself than

the novice user. There is in arboriculture a phenomenon that leads to headlines like

“experienced operator injured by chainsaw”. It’s called complacency. I had the opportunity to attend a professional chainsaw operator instructor certification course a few years back and was surprised that we would be spending 3 of the 5 days in a hands on field school. I was at the time operating a chainsaw on a daily basis and was confident in my ability to drop the tallest tree with little effort. What I didn’t know was that the smallest tree still requires more than a little thought to land it safely where it should go.

The basic geometry of tree falling has remained unchanged from the Stone Age.

In fact beavers, rodents not known for there cerebral abilities, use the same methods as we do. Cut or chew a notch in the side of the tree that has the greatest lean,

then go to the opposite side and make a back cut. Unfortunately Mr or Mrs Beaver sometimes never return to the lodge, they fall prey to the uncertainty of tree felling and get crushed. I’m not sure what goes through a beavers mind when he is felling a tree

but if you are not focused and concentrating on the basics you may not make it back to the lodge either.

The basic technique with a chainsaw involves making a horizontal cut no more than 1/3 of the way into the tree ninety degrees from the intended direction of fall. The tree generally will fall in the direction it is leaning. The next step is to cut a notch by making a cut on a forty five degree angle from above the first cut to meet in a perfect apex. This cut should not run over, under or behind the first cut. It is called a pie cut because it results in a perfect pie shaped piece. The last cut comes in from behind parallel to and slightly above the first; it should stop before it meets the pie by at least one inch. This small piece of remaining wood is called the hinge or holding wood. It will direct the tree and may save your life.

Any variation from this procedure and you will have problems. What problems?

Lack of control is the primary problem. With a large tree the problem becomes larger. If the hinge is cut incorrectly the tree may fall in an unintended direction. If the hinge is cut through, the tree will fall without control and in any direction. Take the time to review basic tree felling technique and don’t let your mind wander while chain sawing. Each cut involves risk and should be performed with care and caution. If you don’t it could cost you not only your lodge, but your life.

Good Leaf Bad Leaf

Now that the yearly crop of leaves has fallen it may be of interest what to do with them next. In this age of recycling it is all the rage to compost your leaves to recycle the nutrients. Well this is a great idea in principle depending on the trees on your property you may want to reconsider this approach. Back in the good old days people used to burn all there leaves and spread the ashes on there garden. While this practice isn’t the best from an air quality standpoint it does eliminate over wintering disease and insect problems on the leaves that may survive composting or just piling up in the woods. While it’s no longer recommend to burn your leaves, selected recycling and compost may be your best solution.

Trees that have old insect infested fruit, like apples, should have this disposed off site or buried to prevent the insect pests from over wintering in the fallen fruit. Similarly leaves from trees that frequently have outbreaks of fungi like lilacs, dog woods and ash trees should be gathered and thoroughly composted for more than one year away from the affected trees. Many trees have gall or other mites that disfigure the foliage with cocks combs or nipple like lumps. These should be moved off site or disposed of to prevent re-infection. Leaf shredders are an excellent way to speed up the process of composting, mixing leaves with other vegetable waste from the house and turning it frequently will promote proper composting.

Now that leaves have fallen and trees are dormant there are things you can do to help them get through severe winter weather. Even though the tops of your trees look dormant there is plenty of action in the root zone. Ensuring the plants have lots of available water at this time can improve survival when temperatures start to rise in the spring. Fall fertilization and watering your evergreens are two cultural practices that can make a big difference in winter survival and help your trees thrive next spring. Be careful when fall fertilizing follow label directions carefully and use low nitrogen slow released fertilizer. Watering and fertilizing can take place from now until the ground freezes. If you want more information on fall tree care contact an ISA Certified arborist, they are experts on tree care and plant health.