Tree Care Guide
Maintain a Wide Circle of Mulch
The majority of tree roots grow outward not downward. Approximately 90% of a tree’s roots are found in the top 12-18 inches of soil and can extend out up to 3 times the height of the tree. These “feeder” roots must compete with grass and other plants for the water and oxygen they need for photosynthesis and growth.
Applying a mixture of woodchips, leaves and compost is one of the best things you can do for your tree’s health. The mulch mimics a natural forest floor, keeping the soil at the base of your tree moist, adding organic matter as it decomposes and reducing competition from grass and weeds. Spread mulch in a circle around your trees as far out as you are willing (the bigger the circle the better for the tree) but ensure that it is not more than three inches deep so that roots can still get oxygen. Keep mulch in a doughnut shape, ensuring it is not touching the trunk as this can cause moisture build up at the trunk base.
Water Every Week!
The most important factor in growth rate and vigour of a tree is water. Toronto
has experienced severe drought for the last several summers. When it does rain
approximately 75% of the water runs off paved surfaces into the storm sewers
never reaching the trees that desperately need it. Most trees (even large,mature ones) don’t get the water they need. Almost every tree in Toronto will experience
drought stress this summer, making them vulnerable to pest and disease attacks.
If you notice leaf discolouration, deformation, wilting or loss, your tree may be experiencing severe drought. The soil under the mulch around your tree should always feel slightly damp and cool. If it doesn’t then run for the hose!
For the first two years after planting, water for 30 minutes, twice per week. In the third year, change the watering frequency to one hour, once per week to give your tree periodic, deep soakings. A soaker hose spread in concentric circles, out to the edge of the tree’s canopy, is the best way to water. If you don’t’ have a soaker hose, you can place a hose without a nozzle in the root area of your tree on a very slow trickle. Move the hose to a new area under the tree periodically to ensure all roots get even watering. Never use a sprinkler to water, since wet leaves are often prone to fungal disease.
It is possible to over-water trees as well. Ensure that there is no standing water under your tree. If the soil is sopping wet after watering, you may need to reduce the duration and/or frequency. This is usually only an issue in poorly drained clay or compacted soils.
Staking
Newly planted trees sometimes require temporary staking. This is usually only the case if the tree is at risk of vandalism, or if it is large and at risk of blowing over in the wind. It is preferable to plant smaller trees with less top growth. Smaller trees will move in the wind, but are unlikely to blow over. Some movement is good, since root and trunk growth will respond and anchor the tree more securely.
If you do stake your tree, use only soft, flexible materials that will not cut into the bark. Ties should be loose and stakes should be at least 2ft out from the tree. Always remove stakes and ties after one year. As the tree grows, ties can cut into delicate conductive tissue located just under the bark of the tree causing serious damage.
Staking is not the way to deal with leaning trees. Trying to pull or force a tree to grow in a certain direction can cause severe structural damage and can actually worsen the lean. It is better to remedy the situation causing the lean.
Sometimes trees will lean if too much growth has occurred on top before the trunk can support the weight. This often happens after lawn or garden fertilizing causes a rapid rush of top growth. Weight should be removed by using proper pruning techniques. The tree will usually resume a more upright position once the extra weight is removed.
As trees get established and begin to grow, they may lean if they are reaching for light. It is best to correct this problem by removing the source of the shade. This may mean pruning overhanging branches of other trees. Once the light reaches the younger tree evenly, it should compensate with growth and straighten itself.
Be Careful Pruning
During the first 3 years after planting, only dead, diseased or damaged branches should be removed.
As trees grow, they do not necessarily need to be pruned further. However, if there are complicating issues with branch structure, it is best to correct them when the tree is young. Corrective pruning is usually done four to seven years after planting, depending on species and rate of growth. This may include removing branches that rub, grow too closely together, or grow in undesirable directions.
Pruning removes leaves from a tree and therefore reduces its ability to produce food. Never remove more than ¼ of the leaf area in any one year. Do not use wound paint after pruning as this may interfere with the natural would closure and may actually accelerate decay.
It is very important that proper cuts be made in the right locations, using the right tools. Please research proper pruning techniques before undertaking any work yourself!
Trees should only be pruned by certified arborists- trained, tree care specialists who have the knowledge and equipment to do the job. Make sure the arborist you hire is certified and has adequate insurance. And don’t be afraid to ask for references. To locate a certified arborist in your area, contact ISA Ontario at 1-888-463-2316 or visit www.isa-arbor.com
6 Things to Avoid
1. Lawn Mower Damage
Lawn mower damage is the number 2 killer of young trees, second only to drought! Establish a wide circle of mulch to protect the base of you tree from mowers and weed-wackers.
2. Tying or Attaching Things to Trees
Rope, string or wire tied around any part of a tree can girdle the bark and cause serious damage. Trees grow a new layer of tissue every year. When this growth is restricted, the flow of water and nutrients up and down the tree is affected. Avoid nailing bird houses or other objects to trees as these create entry wounds for pests and disease.
3. Root Damage
Tree roots are out of sight and often out of mind. Don’t forget that roots extend up to 3 times the height of the tree. Be sure to maintain a large area of soft ground surface around your tree so that roots can grow and will get the water and oxygen they need. Do not install paving or interlocking brick near trees.
When doing renovation or construction in your yard, be sure to establish wide tree protection zones. Small grade changes, such as adding a few inches of soil for sod or grass seeding, can also damage trees by reducing their ability to absorb oxygen through their roots. Piling soil or other materials around the base of trees is a common mistake that can be fatal to trees. Root damage results in weak foliage and leaf loss, but may not become apparent for up to 3 years after the damage occurs.
4. Salt
Salt applied to walkways, driveways and porches in winter eventually works its way into the ground. The trees in you yard can be negatively affected during spring melt when they begin absorbing water. Try chopping away ice in winter and using sand as an alternative.
5. High Nitrogen Fertilizers
Fertilizing your lawn or garden will also affect your trees. High nitrogen fertilizers can cause a rapid increase in height before the diameter of the trunk is large enough to support it. Sprinkling compost is a more balanced and natural way of feeding you lawn and garden and will also be beneficial for your tree.
6. Pesticides & Herbicides
Trees often suffer “chemical burn” when pesticides or herbicides are applied to lawns. This can actually be fatal to trees. Chemical pesticides can also be fatal to beneficial insects, butterflies and songbirds, and have been proven to be harmful to humans and pets. Always use non-toxic alternatives to chemical pesticides. For serious infestations contact an arborist. Inquire about non-chemical methods of treatment.
Pests and Diseases
Pests and disease problems are usually a sign that a tree is under stress. Its natural ability to resist attacks may have been reduced by a combination of factors.
Investigate your yard and try to identify all of the possible stresses your tree faces. Remember that your tree should be well mulched, regularly watered and protected from physical damage (including roots). Improper staking and/or pruning can also cause stress.
Alleviate the stresses to improve the health and vigour of your tree. If only the symptoms (pests or disease) are treated, it is likely that the tree will continue to suffer.
Following the care instructions in this factsheet should help you prevent problems. When in doubt, contact LEAF or consult an arborist before taking action.
Resources
LEAF offers a Backyard Tree Planting
Program within the City of Toronto.
We also offer a wide range of tree care information. For details visit www.leaftoronto.org or call
416-413-9244.
City Trees
To inquire about having a free tree planted in front of your home, or for questions related to city-owned trees, contact City of Toronto Forestry Services
at www.toronto.ca/trees or 416-338-TREE.
Hiring an Arborist
To locate a certified tree care professional in your area, contact the International Society of Arboriculture at www.isa-arbor.com or call 1-888-463-2316.
Organic Lawn and Yard Care
For useful fact sheets visit the City of Toronto’s website at www.toronto.ca/parks/pesticides.html.
To locate private companies that offer chemical-free services visit www.organiclandscape.org or call
416-596-7989
