Conifer Boot Camp

Over the holidays people spent two weeks with a tree in their house that they would not be able to identify if they saw it in the forest. Christmas trees, and holiday wreathes are usually evergreen trees from the group called conifers. Conifers are an ancient group of trees that have been present in the earth’s forests for over 400 million years. They have a well adapted system of survival that has allowed them to prosper up till the present time.

Typically your needled evergreen will be one of three species of trees, pines, spruces, or firs. The easiest way to tell them apart is to have a close look at their needles. Needles are the equivalent of leaves and perform all the usual leaf functions of photosynthesis and water transpiration. Needles have the following distinguishing features that allow you to identify your tree: length, colour and shape.

Pines have the longest needles, 5cm ( 2 in ) or more in length, grouped in bundles that contain various numbers of individual needles. White pines will have 5 needles in a bundle, red pines will have three needles and Scots pines will have 2 needles with a pronounced twist. Jack pines have two shorter needles with no twist to them. Pine needles may have a yellow tinge to them in winter. Most trees for the holiday trade will have colour applied to give them a blue green hue.

Spruces have shorter, 2.5 cm ( 1 in ), needles that are thick and four sided when you break one in half. They may have a slightly skunky smell. You can also easily roll them between your fingers because they are four sided and not flat. They may be very sharp and waxy blue on a blue spruce or smaller and green on a white spruce. Black spruce needles are generally the shortest and may be dark green.

Firs have shorter needles than pines, similar in size to spruce needles. Fir needles are flat and when you break one in half it is decidedly flattened. You can not roll them in your fingers like a spruce tree and they have a strong aroma.

There are many exceptions to these rules as genetics and environment can create a great variety of forms. There are also other species of conifers that have different features than described. These few key points should have you headed in the right direction whether it’s in the forest or just out looking at the last handful of needles from under the couch.

Buy a Tree, Cool the Globe

December 5, 2005

Natural Christmas trees are good things. It takes 10 years on average for a Christmas tree to grow to maturity. In that time, the tree will take 20 kg or 40 lbs of greenhouse gass from the atmosphere. In Manitoba, the average Christmas tree farm has 4000 trees; that is 8000 kg of carbon that’s taken from the atmosphere every year. Impressive figures and that does not account for the hydrocarbon waste that would be created if you bought a plastic tree.

These figures are based on data from Dr. Andrew Weber of the University of Victoria who has put the benefits of natural trees into cold hard facts. The Canadian Government estimates that the average Canadian produces 4500 kg of carbon dioxide, the most common greenhouse gas, per year.

So buying a real Christmas tree is a small step for mankind, but it all ads up.

You are also participating in a century’s old ritual that is good exercise and good fun!

Many Christmas trees are grown right here in Manitoba. Ask where your tree comes from; it reduces the impact on the environment to buy a locally grown tree. It also gives much needed diversified income to farmers. Many times, trees are grown on marginal land that would be subject to erosion if trees were not grown on it.

Every Christmas I am asked “What is the key to keeping a Christmas tree looking good through the holidays?” In one word “fresh”, buy your tree fresh; keep it fresh and cool until you’re ready to bring it inside. Follow a few rules to keep it fresh. When you bring the tree inside cut the bottom inch or 2 cm off the trunk to expose new wood. Put the base of the tree into water and keep it submerged at all times, if it dries out, cut the bottom again. This is hard to do once the tree is fully decked out, so don’t let it run out of water. Keep the tree away from sources of heat, such as baseboard heaters and registers.

In Manitoba, the best source for fresh trees is a reputable local dealer, or Manitoba Christmas Tree Growers Association members, who have u-cut operations across the province. They can be located online at http://www.realchristmastrees.mb.ca .

Basic Cable

Recently I had the unfortunate opportunity of witnessing the destructive power of nature. A weakly attached branch in a large maple tree had broken away in hurricane winds, speeding towards a parked car below. Before the limb was able to hit its unfortunate target, the support cable that had been installed high in the tree restrained the limb and it was left dangling, still attached to the tree. This hundred dollar cable prevented thousands of dollars worth of damage. The homeowner who had lived in the house for many years didn’t even know the cable was there. It had been installed by a previous owner who had the forethought to have a professional come in and assess the likelihood of branch failure and take action. This cable extended the usable life of the tree by ten years and limited the damage caused by the branch failure.

Determining weather or not to install hardware into a tree can be a complicated decision.

Typically cables are installed to limit the movement limbs that appear to have a weak connection to the main trunk. They may also be installed to support weak or decayed crotches or co-dominate stems that have included bark. Stems of trees that are of similar size growing together with bark in between them can fail under extreme conditions. Wind, rain and ice are just three such extreme events.

No one would suggest that you should put safety cables into branches that are obviously dangerous or are sure to fail. An improperly rated or improperly installed cable may give you little more than a false sense of security.

Before you rush out to the local hardware and grab a spool of cable, consider the following. Will your tree benefit from the installation of a cable? Will the tree still pose a significant hazard to its surroundings once the cable is installed? Will the tree still contribute to the aesthetic environment of your yard? Tree cabling is a skilled enterprise, not only from the physical demands of installation, but also to know when and what cabling is appropriate. Each tree has its unique growth habits and structural qualities inherent in the wood. What is an acceptable practice in an oak may be hazardous in a pine. Cables and hardware must be specifically designed and rated for use in trees.

A properly installed cable located two thirds up the length of the limbs will help to reduce the risk of branch failure. Cables should only be installed if they will reduce the risk of failure to an acceptable level. As a professional I always make it a point to tell a client that a safety cable only reduces the risk of failure and does not eliminate it. Buy identifying a potential hazard in a tree you assume liability to properly address the situation. Many times cables are installed after a limb has shown signs of stress or is cracking. It’s important to remember that trees don’t heal wounds or cracks, they simply grow over them. The defect remains and may fail later. Trees don’t regain their strength and no longer need the support of a cable. Cables are a permanent installation and require maintenance. Cables should be inspected at least every three years to make sure they are still in good condition and serving their purpose.

PET Noises

Never one to run from a handy equation, I have brought back an old favorite PET !

No, I’m not bringing the old dog back from the farm, PET is in the equation.

As we had discussed previously, trees can contain potentially hazardous conditions that can cause them to fail with out warning. Recent snow storms and strong winds may have left a few trees a little worse off. More often than not damage to people and property can be avoided by paying attention to your PET. Here is the solution to all this lively repartee. PET is a clever way to calculate the danger to persons and property by trees in our landscape.

“P” refers to the potential for failure in a tree. Conditions that may increase the potential for failure may include; poorly attached branches, co-dominant stems with included bark. These three conditions are often to blame for storm-related tree failures. You may even hear creaking, snapping, or popping. After a failure, torn branches may reveal internal decay and hidden cavities. Trees that topple often have poor root structure or poor soil conditions that predispose them to this catastrophic failure. Toppled trees and shrubs rarely root if they are successfully righted. When failures occur, little can be done to repair the damage.

“E”. The next part of the equation is environment. You only need to stick your head out of the door on a stormy night to see environment in action. Wind, rain, heavy snow and ice all create environments that increase the chance of failure. What we may not think of is the fact that construction, changes in grade, or drainage problems can also create environments with increased risk. Trees fall in the forest every day! What kind of a ridiculous equation is this? Trees do fall in the forest and many times they cause little damage because there are no high value targets to damage. This brings us to “T”.

“T”. The missing factor is a target. You’re new truck is a target, as is your rustic outhouse. All targets are not created equally. Parking your truck under a tree with the potential to fail in an environment conducive to failure creates a risk. Parking yourself in the outhouse under a similar branch in a storm creates an even greater risk. The amount of time you spend in your parked truck is probably less. Therefore the risk to your person is greater while in the reading room.

To summarize the equation: P x E x T = RISK. If one of the factors in the equation is

eliminated or even reduced the risk is greatly reduced. There is no magic bullet or miracle cure that can eliminate all risk. Careful hazard and risk evaluation by an ISA Certified Arborist can suggest ways to limit or eliminate future problems. Have a look above your new truck or whatever target you may value. Don’t wait until you hear PET noises!

Never one to run from a handy equation, I have brought back an old favorite PET !

No, I’m not bringing the old dog back from the farm, PET is in the equation.

As we had discussed previously, trees can contain potentially hazardous conditions that can cause them to fail with out warning. Recent snow storms and strong winds may have left a few trees a little worse off. More often than not damage to people and property can be avoided by paying attention to your PET. Here is the solution to all this lively repartee. PET is a clever way to calculate the danger to persons and property by trees in our landscape.

“P” refers to the potential for failure in a tree. Conditions that may increase the potential for failure may include; poorly attached branches, co-dominant stems with included bark. These three conditions are often to blame for storm-related tree failures. You may even hear creaking, snapping, or popping. After a failure, torn branches may reveal internal decay and hidden cavities. Trees that topple often have poor root structure or poor soil conditions that predispose them to this catastrophic failure. Toppled trees and shrubs rarely root if they are successfully righted. When failures occur, little can be done to repair the damage.

“E”. The next part of the equation is environment. You only need to stick your head out of the door on a stormy night to see environment in action. Wind, rain, heavy snow and ice all create environments that increase the chance of failure. What we may not think of is the fact that construction, changes in grade, or drainage problems can also create environments with increased risk. Trees fall in the forest every day! What kind of a ridiculous equation is this? Trees do fall in the forest and many times they cause little damage because there are no high value targets to damage. This brings us to “T”.

“T”. The missing factor is a target. You’re new truck is a target, as is your rustic outhouse. All targets are not created equally. Parking your truck under a tree with the potential to fail in an environment conducive to failure creates a risk. Parking yourself in the outhouse under a similar branch in a storm creates an even greater risk. The amount of time you spend in your parked truck is probably less. Therefore the risk to your person is greater while in the reading room.

To summarize the equation: P x E x T = RISK. If one of the factors in the equation is

eliminated or even reduced the risk is greatly reduced. There is no magic bullet or miracle cure that can eliminate all risk. Careful hazard and risk evaluation by an ISA Certified Arborist can suggest ways to limit or eliminate future problems. Have a look above your new truck or whatever target you may value. Don’t wait until you hear PET noises!

Leaf Colour

Right now your leaves are losing their colour. The beautiful hues of fall have actually been there all summer long. The colors we see in the fall are normally masked by the pigment chlorophyll. Chlorophyll, the most common pigment, is responsible for the green colour in leaves. Sunlight is composed of many different colors of light. We can see the whole spectrum of light colours when they are broken up in a rainbow. Leaves absorb various wavelengths, or colours of light, and reflect back other colours. The green we see is reflected light that’s bounced back to our eyes. The light that isn’t reflected is absorbed is used to power the machinery of photo synthesis. Photosynthesis is the process that takes gases from the atmosphere, water and using energy from the sun creates sugar. Oxygen is a waste product of this reaction. Light of many wave lengths is used by other pigments, to a lesser extent to create other products in the leaf. Other pigments include caratenoids, that give the orange / red colours we see in carrots and maple leaves. Anthocyanins are pigments that give the blues and purples we see in plum leaves and chokecherry fruit. Many pigments blend together to give you dull brown, like the paint water in kindergarten class after you clean you brushes. At the end of summer, trees begin the process of shutting down for winter and much of the sugar in the leaves is transported elsewhere in the tree. The leaves vascular connections between the leaves and the trees are then plugged, with a layer of thick impervious cells called the abscission layer. The chlorophyll in the leaf degrades exposing the colorful accessory pigments. Only after the leaves have essentially died do we see their true colours. The leaves are then shed as the abscission layer plugging the leaf stem is complete. If we have a long frost free fall the leaves will have much more prominent colors. Trees will however lose there leaves with out frost as the process of abscission and leaf drop, is triggered by shorter fall days. The fall of 2002 was warm and then a sudden cold snap brought the first snow to Riding Mountain. I had the privilege of seeing thousands of still olive green aspen leaves fallen on fresh white snow. A painter could not have painted a more striking backdrop!
Enjoy the fall colors and know that spring is only months away!

Trees a Record of Time

Trees record the passage of time in the texture and size of there yearly growth rings.

Amazing research is being done by Dr Tardiff at The University of Winnipeg. Dr Tardiffs specialty is measuring the age of trees and extracting climactic data based on the size and characteristics of the tree growth rings. This process is known as dendrochronology. The word means literally tree-time, and gives historical and prehistoric climate data for locations in Manitoba. This research goes way beyond counting the rings of trees and estimating their age. So how old is my tree? This question is a frequent one and not always easy to answer. It’s much easier to answer in the past tense, how old was my tree. This is best done after the tree is cut down. There is no easy way to count growth rings in a living tree. It can be done, but not without injuring the tree. A skilled arborist with good local tree growth knowledge can often approximate the age of a tree by comparing it to similar trees that have been taken down in the area.

A tree growing in the forest may live to be hundreds of years old. This is the case for the Old Oak Tree in Souris, Dr Tardiffs studies have located stands of black spruce in the Duck Mountains that are over 300 years old. These are examples of trees that have lived in natural undisturbed environments. As the level of disturbance increases, the life span of the tree decreases. One thing that is known is that site conditions affect the average survival rates of trees.

Research by the International Society of Arboriculture has yielded interesting results on the lifespan of urban trees. All trees need three basic things to survive, soil, air and water. In our increasingly urban environments any one of these could be lacking or present in a form that is not best suited to a tree’s needs. Extreme climactic events do play a role in weeding out the weak and aged trees but are relatively rare. A tree planted in an urban park will last approximately ½ the time it would in nature. Given this fact and the trees we have in our parks this works out to approximately 75 years. In a suburban lot tree life is again halved to 35 years. The trees planted in cut outs in sidewalks can be expected to live 7 years. By comparison how long would you expect a goldfish to live in a tea cup? The single most limiting factor in tree survival is soil compaction. Soil compaction is the breakdown of soil structure through vibration or weight being applied to the soil. Compacted soils are so dense that they exclude air and water that is essential to root growth. Trees without roots don’t survive very long. Soils that were once compacted around Roman villages in England can still be identified from the air by differences in the colour and vigor of the trees and vegetation growing on them. These trees and grasses are less able to survive drought and other stress factors. Romans traveled on foot and built there roads and settlements with out heavy equipment. Two thousand years later we can still see evidence of soil compaction. If you consider the impact of vibratory packers, skid steer loaders and other modern building equipment, the long term impacts of construction must be even greater than we expect. The only effective solution is to avoid soil compaction in the first place and to mulch properly trees to increase the organic portion of the soil. So why plant a tree at all? If you ask this question you may have missed the point. Even if a tree lasts 7 years it still contributes dollars to our local community and increases property values by as much as 10%. Urban trees increase in value through out their short lives. Trees are the only urban public asset that increases in value with time.

It’s worth it to keep planting trees even if they may not last forever. Check with your local nursery fall is an excellent time to plant a tree!

Trees and Summer Flooding

This strange weather we are having may be fatal to your trees!

While it’s true that trees need water to survive, too much water can injure your trees roots.

The top six inches of normal soil is composed of almost equal parts of soil, water and air.

When the soil becomes saturated with water, air is excluded and roots will become stressed.

The amount and extent of damage to the roots depends on several factors. Different species of trees react to flooding differently. The time of year that the flooding occurs also has a direct relationship to the damage it will cause. Another factor is the depth of the flood water and how long it sticks around. These are just a few of the factors to consider.

Flooding in spring along streams and rivers is a normal process and in most years, takes place before the trees have leaves. This type of flooding usually causes little damage for two reasons. The trees are not actively growing so their roots don’t require large amounts of oxygen. The second reason is most river bank, or riparian trees as they are called, have adapted over millions of years to survive this type of flooding. Willows actually have air passages in the tissues of their roots to allow them to survive and even thrive in flooded soils. Damage to trees flooded at this time is often mechanical injury from floating ice, debris or deposition of top soil over their roots. Ash trees will sometimes loose all of their bark up to the high water mark when spring flood waters rise. These types of injuries are often fatal to the trees but are not wide spread. Injuries may go unnoticed as the trees often take several years to ultimately succumb to this damage.

Once the trees have leafed out and are actively growing they are much more susceptible to serious injury from flooding. Temperatures are higher and roots are actively respiring using oxygen in the process of converting carbohydrates to energy. Waste gasses are also lost to the atmosphere and this process is interrupted by flood waters. The roots then start to operate with out oxygen. In this anaerobic state, roots will start to rot quickly if the soil remains saturated. Trees respond by shedding fine feeder roots and shutting down life processes in the larger roots. This in turn prevents the normal uptake of water and the top portions of the tree. The tree will start to exhibit drought symptoms. Leaves will curl and drop and the tree may become completely defoliated. Even though there is plenty of water around none of it is available to a tree without roots. Just as a stranded sailor in a life boat is surrounded by the salty ocean, no water is available to quench his thirst. Trees may die suddenly following this type of flooding or may become weakened and fall prey to other diseases or insects. Trees that are able to survive this type of flooding include, black and green ash, and willow. Trees that may be injured from this type of flooding include, cedars, poplars, cottonwood, birch, Manitoba maple, American elm, hackberry, honey locust, silver maple, bur oak, basswood, buckeye, crabapple, sugar maple, and most pines or spruces. Keep in mind it may take several seasons for the damage to become evident.

Trees that are in shallow depressions may need to be pumped out or drained.

Also when you are pumping out your basement take care that you’re not flooding your valuable trees and shrubs just outside the window.