Trees occurring naturally in forests usually require little attention. But the trees growing in our Urban Forests face challenging growing conditions, and left neglected can become hazards. Proper tree care starts before you even plant your tree. A tree planted properly and given care in the first few years after planting are critical to supporting the long-term health of your tree. A well-established tree should not need frequent maintenance, but there are a few things to consider to ensure it will continue to offer beauty, shade, and habitat for years to come.
Cities are difficult places for trees to live. The average life span of an urban tree is between 7-14 years. Urban trees face high soil compaction, little access to water, exposure to salt, high pH from leaching concrete, and other forms of pollution. Many times a small tree is planted with just enough quality soil to support the young roots, and the needs of the growing and mature tree are overlooked. The condition of the soil should be considered before planting, and maintained throughout the life of the tree.
Ideal soil conditions will have:
Pruning can improve a tree’s health and appearance by removing dead, diseased or damaged branches, and by improving the crown appearance. Well pruned trees grow stronger and faster, and are more likely to withstand the stress of powerful storms, insect infestations and disease outbreaks. Pruned trees also live longer than trees that have never been pruned.
Pruning of dead or damaged branches can happen any time of year, but it is best to wait to prune healthy branches when trees have slowed their nutrient transport in the spring and having fully leafed out. In central New York, it is usually best to wait until mid-June to begin pruning your trees. Pruning often stimulates new growth. This can be problem in the late fall, when brief warm spells followed by freezing temperatures can injure new growth leading to further problems in the spring. Try to target pruning of healthy branches between June and September, or in the winter months before trees have begun leafing out.
Proper pruning technique is also very important. Improper pruning cuts can lead to additional disease and damage. Always use a clean and sharp pruner. You can find more information on proper pruning technique here.
Properly pruning young trees will help your tree develop a strong and healthy crown that will be more manageable and resilient as it ages. Poor branch structure can lead to wounds and weak wood that exposes trees to pathogens and breakage. Structural pruning is a method of pruning young trees that helps the tree to develop a sound canopy over time by encouraging a strong central trunk, and limiting weak branches and branch unions.
Structural pruning focuses on establishing a strong crown leader, eliminating rubbing or crossing branches, and limiting poor branch-to-trunk unions. Structural pruning takes skill and training. We recommend you seek assistance from a certified arborist, or attend training sessions offered by Cooperative Extension.
Mulch is often used to provide extra aesthetic appeal to a landscape. Mulch helps to retain moisture in the soil, which is especially helpful for young trees in times of drought. Mulch helps to impede weed growth and can prevent damage from mowers and weed whackers. Ideally mulch is spread to the drip line of the tree, which isn’t possible in many urban areas. Aim to spread mulch the distance of the drip line for young and newly established trees, and retain at least a few feet radius from the trunk in older trees.
One of the most common mistakes in caring for trees is applying too much mulch and letting it rest again the trunk of the tree. Mulch should be 3-5 inches thick with at least a 1 inch ring around the trunk of tree without mulch. This will limit moisture decaying the bark of the tree, and prevent insects and rodents from building nests at the base of the tree where they may chew bark.
Mulching Factsheet - From the Northeast Center for Urban and Community Forestry.
Proper Mulching Technique Factsheet – From the ISA’s Trees Are Good website.
Know your tree! If you call an Arborist or extension asking for helping to treat a pest a disease problem with your tree, the first thing they’ll ask is what kind of tree do you have. Be prepared to bring in samples or send in clear photographs if you don’t know the species. For more information on how to begin diagnosing pests and diseases, visit the ISA’s tree care website.
Our Master Gardeners and Forestry educators may be able to assist you with diagnosing your tree’s pest or disease. Be prepared to bring in samples or send photographs of the tree and the symptoms, and offer a description of your landscape and history of the tree’s health. Call us at 315-424-9485.
If we can’t help diagnose the problem you can send samples of insects to the Cornell Insect Diagnostic Lab for identification for a $25 fee. The form can be found here. The website also has a wealth of factsheets on a wide variety of insects. Follow this link to go the factsheet webpage.
Last updated July 26, 2019