So You Still Want to Plant a Tree

May 17, 2005,

How to dig a fifty dollar hole for a five dollar tree.

The number one mistake made when planting trees is to make the planting hole too small. A properly dug planting hole is broad and shallow, two to three times as wide as the root ball and slightly shallower. It should be dish shaped sloping down to the deepest part below where the plant will sit. Do not place gravel in the bottom of the planting site as this will result in water being trapped in the finer soil on top of the gravel. This is called a perched water table, and often causes root death from drowning. If you site has poor drainage consider installing drain tiles to help improve the situation.

The number two mistake made in planting trees is to plant them too deep.

Roots need to breath, and don’t grow upwards readily. It is much better to plant trees “high and proud” as the saying says, than it is to have buried them in a shallow grave. More than one group of trees of different sizes has been evened up by planting the tallest one a little deeper. Only several years later after the tree has died, does digging it out reveal that it was planted too deep. Roots and tree trunk tissues are adapted to being under and over the soil respectively. The reverse never works. If you see branches coming from below the soil level it’s a tell tale sign that the tree was planted too deep.

Once you have selected your tree and dug your hole its time to put it in the ground.

In the past the most nursery stock was available as bare root, for smaller trees or balled and burlapped for larger landscape feature trees. Container grown trees are a relatively new phenomenon with tremendous advantages, and one big problem. This is the phenomenon of girdling roots. Trees grown in pots will have roots that circle the margin of the pot. When you take the tree out of the pot you will see these roots at the edge of the root ball. It is advised to take a sharp knife and cut these circling roots in a few places around the root ball to limit the chance that they will grow to strangle the trunk of the tree. Girdling roots are much less of a problem with balled and burlapped trees as exposure to air will prune the roots before they get to the edge of the root ball.

Place your tree into the planting hole carefully and fill the soil back into the area surrounding the root ball. The soil should be the same as the soil surrounding the planting site. Mixing back fill soil with peat or sand is not recommended as it creates problems with root penetration beyond the planting hole as the tree grows. The trees roots may never extend past the amended soil. Do not put soil on top of the root ball, don’t bury the trunk. Once your tree is in place and has been backfilled, gently pack the soil around the root ball to eliminate air pockets. Watering after planting is essential to keep the new roots from drying out and to establish a moist link between the planting site and the ground water. If your tree is unstable it may require staking or guying. This subject will take an additional article as it is often done incorrectly. For further advice on tree planting contact an expert, an ISA Certified Arborist.

So You Want to Plant a Tree

May 1, 2005,

The number one mistake made by home owners planting trees is to choose a tree that will be too big for their planting location. Always take into account the mature size of the tree and choose a tree that fits your site. Big site big tree, small site small tree. Look up, way up, are there wires? If so plant a tree that will mature into a small size. Crab apples, cherries, and Asian maples are ideal candidates for small sites. Avoid planting your tree over under ground utilities that may require service or interfere with the roots of the tree. Take our harsh weather into account when planting. All trees moderate the environment and reduce pollution. Large shading deciduous trees planted to the south will shade you from the summer sun while letting winter rays through. Evergreens planted to the north and west can reduce your heating bill. Carefully analyze your site before you select your tree.

Once you have your site conditions figured out chose a tree to fit those conditions. Some trees have a great degree of adaptability to adjust to different site conditions. Shade tolerance, drought tolerance and ability to survive alkaline or flooded soils are just a few potential problems. Adverse site conditions effect the survival of the trees you will plant. Hardiness refers to a trees ability to survive low temperatures. This means not only the minus forty blast of winter but the late frost and May snow storms that we occasionally receive. Native species like the green ash wait until the last frost has passed to send out leaves. Introduced species may be fooled by late winter warm spells. Trees that break dormancy early may be caught with there leaves out too soon. Check to see that the tree you plan to plant is fully hardy. Disease and pest resistance are two areas that must be addressed to avoid disappointment and expensive maintenance in the future. Choose a tree that is healthy and vigorous. Look out for old stock or trees that have just been planted into pots. Once you have crossed all these criteria off the list, you have to pick a tree that has the potential for good branch structure. Be on the look out for weakly attached branches with narrow “v” like crotches. These may fail later in the life of the tree. The process of selecting and promoting permanent branches is easy once you know the basics and will be the topic of a future article. It’s enough to say that all of the branches you have on your 5 to 6 foot tree purchased from the nursery will probably not be there for the life of the tree. Most will be removed while the tree is young for clearance and shaping in the landscape. I guess there is a lot more to planting a tree than just throwing it in a hole!

We will get to actually planting a tree next time, after the snow melts!

Tree Roots Part 2

If the purpose of an inquiry is to dig deeper into the dirt, this article is no exception.

This inquiry uncovers the secret lives of roots.

In our last discussion we touched on the three basic functions of roots:

1) Physical anchoring the above ground portions of the tree

2) Absorbing and transporting water and mineral nutrients

3) Storing starches, sugars and other food reserves

We also introduced the concept of a rhizosphere composed of roughly equal parts of, water, air, mineral soil and a small component of organic matter.

Trees use fine absorbing roots to gain access to minerals dissolved in water that are vital to plant growth. The process by which water is absorbed into the plant is called osmosis. This system is entirely passive. If the root is dryer than the soil it will take in water, much as a dry sponge soaks up a spill. When the root is full of water it stops taking it in.

By the reverse process, when the root is wetter than the soil surrounding it must lose water, much as a wet sponge on a dry surface loses water.

What this means for your tree is that when soil conditions become too dry it will lose water to the soil rather than taking water in. Trees have evolved various methods to maintain water in drought conditions. One way to do this is to shed many fine absorbing roots during periods of drought. The thicker structural roots have a waxy coating that prevents moisture loss and uptake. When conditions permit the fine absorbing roots will be re-grown and the process will begin again. Trees also form beneficial associations with a group of fungi known as mycorizae.

This term translated literally means fungal roots. These fungi grow into the roots and exchange water and mineral nutrition for sugar provided by the tree. This web of fungi around the roots can extend the surface area of the absorbing roots by as much as ten times. Additionally the fungi are better adapted to adsorb soil water when it is in short supply. These fungi are very specific to the types of trees they join in partnership with. Fortunately most soils contain billions of these fungi.

So why do I have roots growing all over my lawn. Roots generally grow downwards guided by a process called geotropism. Gravity drives this process and ensures that roots end up in the soil rather than on top of it. There are two reasons why roots come to the surface. Number one, your lawn is so compacted that the roots are unable to get enough oxygen to allow them to grow at depth. Number two, the constant removal of leaves has interrupted the soil building process. Normally, in a forest setting, roots would be showered annually with layers of leaves and plant debris that would cover the roots and decompose into a rich organic soil.

Soil compaction is the process where air is excluded from the soil by packing the soil particles tighter and tighter. Soil structure is broken down and the soil can become as dense as concrete. Roots have an extremely difficult time penetrating this type of soil. Existing roots will be injured and may not recover from soil compaction. A recent study has shown that six passes over the roots of a tree with a construction tractor will result in the death of ninety percent of the roots in that area. Construction damage effects normally are not seen until three to seven years after the

damage is done. People look out one spring and the trees they bought the house for are dead.

There are things that can be done to prevent construction injury, most are related to preventing

soil compaction.

Tree Roots Part 1

Get Back to your Roots Laddie!

The truth of this statement by a Scottish Kilt salesman, leads us into the largely unseen world of roots.

Roots are the unsung heroes of the plant world. Without the obvious utility of branches or the chromatic charisma of the leaves roots work tirelessly year round.

Roots provide 3 basic functions to a tree:

1) Physical anchoring the above ground portions of the tree

2) Absorbing and transporting water and mineral nutrients

3) Storing of starches, sugars and other food reserves

In addition to these 3 basic properties, roots synthesize important bio-chemicals that regulate how the above ground parts of the tree function.

There are many different types of roots. Trees typically have one or two basic types.

Tap roots are deep probing roots that serve to anchor trees and gain access to deep water resources. Tap roots may extend several meters directly below the trunk of the tree. The burr oak is the classic example of a tap root species. This deep root will be accompanied by many shallower fibrous roots and enable burr oaks to resist drought. Tap roots are the exception in the world of trees; fibrous roots are much more common. Tap roots normally die off and are replaced with lateral roots as trees mature.

Trees like the white spruce and Manitoba maple are good examples of fibrous rooted trees. Large numbers of shallow branched roots extend laterally from the base of fibrous rooted trees. Most often 90% of roots are in the top 150cm, or 6 inches of the soil. This area is called the rhizosphere, in English “the sphere of roots” or “root world”. Roots rely on three essential things in proper proportion in order to grow and thrive. Oxygen, found in the soil atmosphere, mineral nutrition in the form of soil particles, and water are the three basic requirements for healthy roots. Organic material constitutes a forth and smaller component of the soil. The rhizosphere has these components in a balanced proportion.

Pores in the soil are created between soil particles and by living soil organisms. These organisms digest soil particles and each other creating organic matter essential to tree growth. The proportions move in and out of balance as rain water fills pores in the soil and displaces air. Soil compaction can also disrupt the amount of air and water in the rhizosphere. Large tree roots are mainly structural and do not absorb substantial amounts of water or nutrients. The smallest roots are the water adsorbing roots, doing the vast majority of nutrient absorption. These small roots grow and fall off in response to seasonal changes in the soil climate. Winter cold or long periods of saturated soil will result in the loss of many of these small fine roots. Replacing them in the spring or when soil conditions are favorable to root growth is an energy intensive business. All this activity goes on largely unseen by the average person. Things we do above ground will often have negative effects on the delicate balance of the rhizosphere. We will dig deeper into root world in our next column, as we discuss root damage during construction.

How Sunlight Ruins Your Trees

This may come as a surprise, but excessive exposure to sunlight can ruin your trees. Before you rush out to the yard with a backpack full of sun block, consider the following; competition for sunlight is the primary agent that shapes trees in the forest. Without this evolutionary pressure, trees may not have developed into tall, stately plants. Growing tall is energy-intensive business. When competition for sunlight is removed, trees may grow horizontally with large spreading limbs. The tree’s lower branches may touch the ground, looking like the legs of a stool. This appearance is sometimes called stooling. The name actually refers to a method of propagation where some branches may root when they come in contact with the ground. If this appearance appeals to you, you have a unique eye for landscapes. Large lateral limbs on trees may be weakly attached to the main trunk and prone to failure when heavily weighted with snow or ice. What are the solutions to this potentially devastating problem? Timely corrective pruning of young trees is the best approach. Trees grown in landscapes can be trained early, through careful pruning, to limit the growth of large, low limbs. Another option for prevention is to design tree plantings in groups to shade each other, mimicking the natural processes that keep trees growing upright. Unfortunately, these processes can't be implemented on large existing trees. Large cuts on the lower trunks of mature trees usual leads to extensive decay. This decay may cause the trees to fail at the points where the limbs were removed. Careful reduction of large lateral limbs can lessen the impact of eventually removing these large branches. Cabling and bracing, the installation of support rods, and cables or props can reduce, but will not eliminate the risk of limb failure. Put the sun block away and reach for a modern book on tree pruning. If you have a mature tree that has large low limbs that require removal, consult an ISA certified arborist. A small fee paid for a consultation will certainly pay off in the long run.

NGO's

Non-government conservation organizations play an important role in the longterm viability of urban forests and private land forestry.

As the government increasingly devolves itself of the responsibility for the stewardship of common resources like forestry and natural lands, non-government organizations act as an important watch dog to help shape government policy.

Recently, we have seen government (in an effort to reduce spending) leave the monitoring

and management of natural lands to industry and other agencies with a vested interest in exploiting the resources they protect. Without strong, informed groups to question the wisdom of some decisions, in the future we will wonder how we missed what, in hind sight, was so obvious. As Joni Mitchell so apply stated, with reference to a “Tree Museum”, “before you know it, we’ll be paying a dollar and a half just to see’ em”.

This doesn’t mean that industry, government and advocacy groups should be at each others throats. To the contrary, at times they may be important allies.

One doesn’t have to look far to see examples of how groups working together can result in benefit to all.

In the early 1990’s, the Province of Manitoba was looking to reduce expenditures, the Dutch Elm Disease Program, a vital protection for Winnipeg’s urban forest, was cut to the point of failure.

People within the department of natural resources knew the negative effect this would have on the long term survival of the urban forest.

What was needed was an educated public to inform political leaders of the importance of this valuable public asset.

The Coalition to Save the Elms was born and public outcry helped reverse the decision to cut the program, and Winnipeg still has its elms.

The moral of the story is government, quasi-governmental organizations, and private organizations need to work together to ensure that what’s best for all is archived.

It’s not fast, it’s not expedient, but it does work.

Without partners and strong connections to the community, who will speak up when the next program is on the chopping block?

The Ghost of Christmas Trees Past

I have a confession to make. I was once a misguided opponent of natural Christmas trees.

I was under the false perception that buying a “real” Christmas tree resulted in the destruction of a living tree to the determent of the environment. For a few years I put up petroleum based plastic tree.

Then one year as a fund raiser while in college, our student forestry group took on a project growing and marketing real Christmas trees. We really inherited some one else’s work because growing trees takes upwards of ten years. We went out in August and picked out our trees, marking them for harvest once the weather was cooler. They had been previously trimmed and shaped to have the perfect Christmas tree form. Once harvested, we carted our festive bounty to the center of town. The stand was set up in the typical fashion, with rows of trees ready for the holidays. The operation was quite a success and is still an ongoing fund raiser for the Paul Bunion Forestry Club. It’s also a lot of hard work and many cold hours of waiting for customers. It made a real tree convert out of me.

The fact is that a real Christmas tree spends 10 years of its life growing on a farm, storing carbon and providing oxygen and wildlife shelter. For every Christmas tree that is harvested 2-3 trees are planted in its place with the hope that they will grow to maturity. Small fast growing trees store carbon at a greater rate than older mature trees. Real trees are grown by real people quite often on marginal land. Tree farming is a source of diversified farm income. In many towns and cites Christmas trees are recycled into mulch and compost to slowly biodegrade and returning to the environment.

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 on line at http://www.realchristmastrees.mb.ca/

You can also phone a real person, Patricia at 204-453-7105 for more information.

A final word of advice from my vacuum cleaner repair man, “Scots pine needles are best swept”.

Happy holidays and enjoy a real Manitoba Christmas tree.