Mulch

Mulching your landscape can have tremendous benefits. Mulching incorrectly can cause significant problems.

Mulching is the practice of layering two to four inches of shredded, chipped bark or wood chips to cover the root zone of trees and shrubs. Mulching mimics the natural process of leaves and debris falling to the forest floor in the fall. If you walk in the forest in the late fall this leaf mulch layer will be at its maximum depth. Decaying over winter this mulch layer decomposes into nutrients. This thick layer will have been reduced to a thin mushy crust by spring when the plants begin to grow.

The primary benefit of mulch is moisture retention. Maintaining moisture in the soil increases the amount of fine root growth. Increased root area results in improved tree health and drought tolerance. Keep in mind that too much mulch can decrease the amount of air in the soil and suffocate roots. Ideal soils contain equal parts of air, water and physical soil. Mulching can be expensive if you use bagged imported materials. A low cost locally available material may make sense for your landscape. With the increased popularity of industrial wood chippers used by arborists to recycle tree waste, an affordable mulching material is at hand.

Mulch has varied properties based on the parent material. Typically composted hard wood chips are the preferred material for most mulching. Ideally the mulch should sit for a period to break down and age. During this process bacteria partially digest the fresh brightly colored wood chips and turn them a darker shade of brown. This process is more than just cosmetic. If you put freshly chipped material in your landscape the decomposition process may rob your trees and shrubs of essential nutrients, especially nitrogen. In the initial stages of decay microbes take nitrogen from the surrounding soil. As the mulch ages this process reverses and the decaying mulch provides a slow released source of nitrogen and other macro and micro nutrients. Wood chips from pine or spruce will acidify the soil as they decompose. You can use this to your advantage if you have plants that prefer these conditions.

Once you have your supply of aged wood chips, weed the area to be mulched. Put the mulch in an even layer 2 to 4 inches thick. Do not allow the mulch to touch the bark of the trees and shrubs directly. Leave a gap of 3 to 6 inches between the bark of the tree and the mulch layer. Don’t pile the mulch against the tree like a mulch volcano. Try to be consistent with the depth of your mulch.

Mulch should be spread out to the drip line on most small trees. The drip line is an imaginary line drawn from the tip of the longest branch to the ground. When rain falls this is where the drops of water will drip to the ground. While it’s not necessary to completely remove your mulch in the spring it is a good idea to refresh it. Refresh your mulch annually by raking it out and adding new material to maintain the 2 to 4 inch depth. If the mulch is breaking down slowly you may only have to level and adjust the depth with out adding new material. Make sure the mulch is not becoming compacted an excluding air. Mulch is a great benefit to your landscape when applied wisely. We will continue with mulching problems and solutions next time.

Basket Case

When you’re thinking of planting large trees you will be making a choice between two popular types of nursery stock. Traditionally trees between two inches in trunk diameter and four inches in diameter have been available with their roots wrapped in a burlap ball. The trees were excavated by hand in the growing field. Once the sides of the tree were excavated burlap was wrapped around the root ball to help maintain the soil around the roots. Then, carefully the wrapping material was worked under the roots. The burlap was all eventually stitched together into a ball. This type of stock is called balled and burlapped. This was the industry strand for many years. The problems with this labor intensive system are two fold. The first problem is the loss of roots. A typical ball and burlap tree has had over eighty percent of the roots removed. Many times the ball will fall apart when planting, resulting in more root damage. The second problem is the incomplete removal of the balling twine and burlap. The twine may be wrapped around the top of the roots, the root collar. This will result in the tree being girdled as it grows and the trees dying as a result. Synthetic burlaps and treated natural burlaps decompose slowly in certain soil environments.

Many times you will find burlap intact on trees that have been wind thrown years after they were planted? Roots can have a tough time penetrating these materials. Natural burlap also acts as a wick and will draw water away from roots resulting in moisture stress in newly planted trees. It is important to remove all twine and burlap from the top of the root ball once trees are in the planting hole. It is recommended to remove the burlap from the sides to a height 4 inches below the final soil grade. This will allow roots to establish quickly in the top 4 inches of the soil and prevent the burlap from wicking. It is also a good idea to cut several slits to aid root penetration in the lower portion of the root ball burlap. It is best to do this once the tree is in the hole. In recent years a new format of tree planting container has emerged.

Planting baskets are galvanized wire baskets lined with burlap that allow trees to be dug moved and planted with much less labor. Trees are typically dug with a tree spade on the front of a small front end loader. They are then placed into a wire basket lined with burlap. The burlap is then folded over the top and the handles of the basket are folded over the top and bound with twine to complete the root ball. The same cautions apply when planting wire baskets. Remove all burlap and twine from the top of the ball. Remove all wire that may girdle the roots or stick above the soil level. Remove all burlap from the top 4 inches of the basket to allow for root growth one planted. Failure to allow the roots to establish will result in increased chance of wind throws and tree mortality. I have seen trees that were planted fourteen years previously still have intact burlap when they blow over and the roots popped out of the ground. Large trees give instant results, small trees establish quicker and will eventually over take their larger counterparts in the landscape.

The Essential Rot

Trees are long lived organisms living in hostile environments that are full of wood rotting fungi and bacteria. It may come as a surprise that trees are essentially composed of sugar! Cellulose, the basic building material for all woody plants, is composed of long strings of sugar joined together.

Bacteria and fungi have the ability to break down the complex sugars in cellulose and digest it. Trees have developed the ability to resist this process through the development of additional chemicals that resist the initial infection and colonization of wood tissue by these pathogens. These resistive chemicals are mostly specialized oils and aromatic hydrocarbons called turpenes and phenols. The tree creates these chemicals in response to the presence of fungi or bacteria and they clog the living cells and passageways in the wood preventing the spread of these wood digesters into new tissue. The resulting process is called compartmentalization.

The process of compartmentalizing the damaged tissue results in it being walled off with an impervious protective layer. Much like the unfortunate crew member that was on the wrong side of a water tight barrier in a sinking ship, living cells on the other side of this protective wall are sacrificed.

If you want an example that is closer to home, look in your wood pile and you can see areas of discolored wood surrounding dead branches or cavities in your split wood. These discolored areas are the chemical barriers that formed the walls of the compartment that contained the spread of the fungi or bacteria in the tree. Wood is a complicated matrix of tissues that have connections upwards, downwards, laterally and towards the center of the wood. Boundaries must be set up in all these directions to prevent the fungi and bacteria from spreading. This process is very energy intensive. Creating the chemical barriers takes energy and the lost energy resources behind the barrier are sacrificed. These resources are lost forever and will be converted to simple sugars and digested by rot organisms. If the tree is successful, it keeps living and grows around the compartmentalized area with new tissue. If it doesn’t the rot will overwhelm the tree and it will fall to pieces. Once the tree is no longer living, no new boundaries are set up and the decay organisms have the advantage. The only thing that stops rapid decay is the lack of a suitable environment and the resistive chemicals left by the living tree.

The decayed tree falls back to the forest floor and is eventually converted into nutrients that will feed the future forest.

In the Zone

Are you thinking of replacing a tree that has been damaged by winter storms? This can be an excellent opportunity to improve the look of your landscape. Many times we plant trees because they are available and not because the tree is right for the location.

“Price is right planting”may have left you with the wrong tree in your yard.

The most important factor in choosing a tree is its growth habit and mature size. I know of two people who have large spruce trees directly aligned with their front doors. The front of a house should invite visitors to enter, not confuse them with which door to use. Even if cultural norms dictate using the back door, the front door should be highlighted.

The way to accomplish this easily is to consider your yard as a group of 5 zones, Zone number one is the area directly adjacent to your house, or the foundation area. This area should be limited to trees that have a mature height of less than 1/2 the height of your house or approximately 5 feet. This assumes that your house is one story. This will ensure that your pyramidal cedar is not growing into your eaves. This zone should extend to a distance equal to the height of your house or 10 feet from your house. Zone number two is the area directly in front of your house this area should be limited to trees that do not mature to a height of more than one story or 10 feet. This will ensure that your house isn't buried under a huge tree or your lawn shaded out of existence. These plantings should never break the sight line from the approach to your house and the front door. The third and forth zones are the two areas to the sides of your house. These side yards are where you should plant medium trees that will mature to a height of one to two stories. The fifth and final zone is the rear of the house this zone starts at a distance equal to two to three stories from the rear foundation or 30 feet. This is the area to plant those large trees that will be giant specimens and form a back drop to your home.

These guidelines are, by necessity, overly simple and can be adapted to a wide variety of situations. If your lot is smaller, you may not have a location for a large tree. Similarly, if you are on a large acreage, you may be able to plant large trees in your front yard. Just remember to keep the front door as your focus even if it’s revealed to you as you pull up the front drive of your acreage. Mastering a few easy concepts in tree selection and placement can reduce your overall maintenance and increase your satisfaction with your landscape as it grows. If you need detailed recommendations on the correct tree species to plant in your specific area, contact an ISA certified arborist.

Philip's Amazing Mad Capped Horse

We are all students of arboriculture, learning and expanding our knowledge every day.

A simple phrase proposed by a student from Deloraine, can unlock the mystery of tree identification.

The first thing that you must know when looking at a tree is what tree you are looking at. Previously we had discussed ways of identifying conifers, also referred to as evergreens. Mad cap horse is a simple way to remember the most common trees that have opposite branch arrangement. The way buds and branches are arranged on trees is one easy way to tell them apart. Maple, Ash, Dogwood, Caprifoliaceae, and lastly Horse chestnut all have this bud arrangement. Caprifoliaceae is a group of plants that include honeysuckle and elderberries.

When you look at a twig and the buds are exactly opposite each other on the twig, the buds are said to be oppositely arranged. The most common arrangement other than

opposite is alternate. This means the buds are arranged in a zig-zag pattern one on one side, then one higher up on the other side. Trees that have this arrangement include, elm, oak, birch, willow, locusts, hackberry, hazel and many others. With this basic information you can identify many of the trees on your street or in the woods. To go beyond this you need a good field guide with a proper key.

The first question in most keys is bud arrangement, opposite or alternate. If you remember Philips mad cap horse you may be able to get the answer without having to work through your key. Once you identify a tree several times you may be able to pick it out quite easily.

Humans are hard wired to differentiate subtle visual differences. This instinct helps babies identify their mothers. Later life the same instinct helps to identify your friend’s car! Once you know the characters in the forest lets you begin to know the interplay that goes on between them. Take time to remember the word key and practice your tree ID.

A high quality field guide is a great investment. When in doubt contact an ISA certified arborist as they are experts in tree ID. Every arborist is a student and if they are lucky they learn something new each day.

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 .