Maintaining both our newly planted trees and our mature trees is essential to maximizing the benefits they provide. Sometimes simple steps can provide maximum protection, such as keeping lawn mowers and weed-whackers away from tree trunks. The Arbor Day Foundation has several excellent resources.

Title: How to Kill a Tree
Sponsoring Organization: Tree City
Description: A simple and entertaining pamphlet on How To Kill a Tree and How to Save a Tree. This Tree City bulletin shows you the top ten tree killers so you can avoid these mistakes.

Watering and Mulching
Protecting Your Tree
Tree Staking
Pruning and Arborists
Managing Fallen Leaves
The Importance of Watering and Mulching

treeNewly established trees need to be watered regularly to ensure their long term health.  And, if there's a drought, even mature trees need to be watered.  Mulching helps to retain the water in the soil, reduces runoff and adds important nutrients to the soil as it decomposes. 

Title: Tree Care Tips & Techniques
Sponsoring Organization: Arbor Day Foundation
Description: Scroll down to “Tree Watering” to learn how and when to water trees, especially during the first two years.

Title: Ask an Arborist: How Do I Know My Trees Needs Water?
Sponsoring Organization:: Arbor Day Foundation
Description: Helpful 3½-minute video on how to water your tree.

Title: Tree Care Tips and Techniques
Sponsoring Organization: Arbor Day Foundation
Description: Scroll down to “Mulching” to learn how to apply mulch around the base of your tree and how mulch benefits your tree by keeping weeds down, slowing moisture loss, and keeping mowers away from the trunk and roots.

Title: Ask an Arborist: Why Do We Mulch?
Sponsoring Organization: Arbor Day Foundation
Description: Excellent 4-minute video explaining mulch application. How much mulch? What type of mulch? What is “volcano mulching” and how can I avoid it? When should I renew mulch around an established tree?

Protecting Your Trees

Roots and Trunks
Deer, Insects, Disease and More
Invasive Vines
Root and Trunk Protection

people protecting roots

Protecting trees is important for their health and longevity.

Root protection
Title: Ask an Arborist: How Do I Avoid Damaging My Tree’s Roots?
Sponsoring Organization: Arbor Day Foundation
Description: Helpful 5-minute video about protecting tree roots. Most of a tree’s surface roots grow vertically only within only the top two feet of soil. Most of the tree’s surface roots grow horizontally out towards the tree’s dripline. To avoid root damage, install mulch from the trunk flare of the tree out to the edges of the dripline, which is demonstrated in the video. This will keep mowers and weed-whackers away from the trunk and roots.

Trunk protection
Title: Ask an Arborist: How to Mow Grass Around a Tree Trunk?
Sponsoring Organization: Arbor Day Foundation
Description: A 4-minute video about protecting trees planted in fields. If possible, create a grass-free circle around the trunk to keep mowers and trimmers from contacting and harming the trunk. If that is not possible, put a flexible tube around the tree to protect it while using the trimmer.

Protecting your Tree from Deer, Insects, Disease, and More

photo of deerDeer can damage newly planted seedlings as well as established trees by eating buds and leaves, and rubbing thier antlers on the tree trunks. Both insects and disease can impact tree health. There are four non-native invasive insects that require particular attention due to the damage they are causing to our trees in Westchester. These are the Asian longhorned beetle (ALB), emerald ash borer (EAB), hemlock woolly adelgid (HWA), Beech Leaf Disease, and spotted lanternfly (SLF). For detailed information on these and other insects and diseases that can harm trees in New York State, refer to the NYS DEC website below. In addition, you can sign up to receive alerts from Cornell Cooperative Extension (Westchester), NYSDEC and Lower Hudson PRISM.

Preventing deer damage
Title: Damage Caused by Deer
Sponsoring Organization: Kansas Forests
Description: A one-page article with five ways to repel deer from browsing and rubbing antlers against a tree.

Title: Forest Health Issues: Pests That Can Harm New York State Trees
Sponsoring Organization: New York State Dept. of Environmental Conservation (NYS DEC)
Description: Learn about the symptoms and signs, hosts, biology, and available control strategies of many of the harmful insects and diseases that threaten trees and forests in New York State.

Title: Insect and Disease Problems
Sponsoring Organization: International Society of Arboriculture
Description: Insects and disease threaten tree health. Learn how to examine your tree to identify problems.

Pet waste and road de-icing salt

Title: Trash and Animal Waste
Sponsoring Organization: New York City Parks
Description: A one-page fact sheet that explains the harm to trees done by liquid and solid dog waste, by de-icing salts and by trash. It provides some suggestions to prevent these problems.

Protecting your Tree from Invasive Vines

vines and stop signInvasive vines growing up electric polesThree of the most prolific invasive vines harming trees in Westchester County are Oriental bittersweet (Celastrus orbiculatus), porcelain berry (Ampelopsis brevipedunculata), and English ivy (Hedera helix). While these destructive non-native vines are highly visible hanging from trees along our parkways, these silent killers can also invade your yard and destroy your trees. Oriental bittersweet and porcelain berry vines can quickly engulf and strangle trees, becoming thicker and woodier with age. They weaken a tree by blanketing the tree’s own leaves, thereby blocking needed sunlight, and ultimately kill the tree. English ivy is a non-native, invasive evergreen vine that has been widely planted in gardens as a ground cover. Unfortunately, this vine quickly grows up tree trunks, damaging the bark, weakening the branches, blocking sunlight, and killing the tree.

When removing these vines from your trees, take special care not to touch poison ivy, mistaking it for one of these vines, because contact with poison ivy can cause severe rashes. If you are unsure, contact a professional. Below is a well- illustrated guide to help you distinguish invasive plants from their native look-alikes, like poison ivy, which actually is a native source of berries for birds. (Mistaken Identity: Invasive Plants and Their Native Look-Alikes)

Refer to theCombating Invasive Species for detailed information on identifying each of these invasive vines and how to eradicate them.

Title: How to Identify and Remove English Ivy
Author/Source: Herndon Environmental Network
Description: Extremely informative six-minute video of an expert from the Herndon Environmental Network discussing why English ivy is considered a harmful invasive plant and how to remove it. She also gives a great demonstration using plastic straws and a piece of string to show how the vine kills trees.

Tree Staking

Staking is used to support and affix recently planted trees. Sometimes it is not necessary to stake a tree, but other times it is very beneficial. 

Title: Staking and Guying Trees
Sponsoring Organization: University of Minnesota Extension
Description: Clear instructions on when and how you should stake your new trees

Tree Safety

If you need assistance managing your trees, contact an arborist to assess their health and your safety.  Be sure to find a qualified arborist.

Tree safety
Title: Recognizing Tree Risk
Sponsoring organization: International Society of Arboriculture
Description:Three-page guidance on how to identify and manage tree risk.

Title: Managing Hazards and Risk
Sponsoring organization: International Society of Arboriculture
Description: This website provides helpful information about recognizing tree risk, storm-related tree damage, and avoiding tree damage during construction.

Pruning and Arborists
In Westchester County most private arborists will inspect the condition of your trees at no charge. Make sure the arborist is certified by the International Society of Arboriculture (ISA) or another recognized program or government agency as a tree expert, and is insured. After the inspection for any pruning or pest issues, the arborist will give you a work proposal setting forth costs. When you make an appointment for the inspection, confirm whether this will be the procedure.

Title: Why Hire An Arborist?
Sponsoring Organization: International Society of Arboriculture
Description: Discusses International Society of Arboriculture (ISA) certified arborists’ expertise regarding the care of trees. They provide services such as; pruning, tree removal, emergency tree care, planting and plant health care.

Title: Tree Care Tips and Techniques
Sponsoring organization: Arbor Day Foundation
Description: Scroll down to “Pruning” to learn why it is important to prune and when to prune.

Title: Ask an Arborist: Why Do I Need to Prune?
Sponsoring organization
: Arbor Day Foundation
: Two-minute video for residents explaining reasons for pruning--safety of people, health of the tree, and aesthetics.

Title: Ask an Arborist: The ABC’s of Pruning
Sponsoring organization: Arbor Day Foundation
Description: A 5-minute video demonstrating the basics of tree pruning, primarily done in winter.

Title: Ask an Arborist: What Are the Rules of Pruning?
Sponsoring organization: Arbor Day Foundation
Description: A 3-minute video demonstrating pruning instructions, primarily in winter.

Managing Fallen Leaves

vine with green leaves

Leaves provide summer shade, autumn color and do the work of photosynthesis. But in autumn they fall to the ground and may cause concern when they cover grass lawns. There is good news. There is an alternative to using leaf blowers to blow the leaves into piles and carting them (and the nutrients they contain) upstate.
For small or medium quantities of leaves, mulching-in-place, also called mulch mowing or leaf mulching, provides an efficient and environmentally friendly solution. Mulch mowing involves mowing over the fallen leaves, thereby chopping them into tiny pieces and distributing them between the grass blades, providing the lawn with needed nutrients.

For yards that accumulate huge quantities of leaves, excess chopped leaves can be applied as mulch under your trees, shrubs and on your vegetable gardens and flower beds. This mulch will eventually break down into compost that will benefit all of your plants. For more information, go to Planting Westchester’s section on soil and review on the Mulching tab.

Mulch mowing enriches the soil, promotes moisture retention, and reduces the pollution and health risks created by gas-powered leaf blowers and trucks transporting leaves off site,

Below are several excellent websites that explain how to mulch mow and the many benefits it provides. The “how to” videos are particularly helpful.

Title: Love ‘Em And Leave ‘ Em An initiative to reduce organic yard waste
Sponsoring Agency: Village of Irvington, Westchester County
Description: This website provides specific information on how to manage your yard with environmental impacts in mind. The site provides detailed information on leaf management by mulch mowing for homeowners, landscapers and municipalities. It contains a toolkit to help you get started, as well as training videos in English and Spanish. The site also promotes use of battery-operated electric yard tools as an emission free alternative to gas powered tools.

Title: Leave Leaves Alone!
Sponsoring Organization: Leave Leaves Alone
Description: This website was developed by a group of residents in Bedford, NY who formed the organization to educate landscapers and homeowners about the benefits of environmentally thoughtful landscape management. It provides great videos on leaf management as well as information on the problems associated with gas-powered leaf blowers.

Title: Leaf Mulch Mowing
Sponsoring Organization: Scarsdale Village
Description: This website provides an exceptionally clear video on the mulch mowing done in all of Scarsdale Village parks. Also provided is a toolbox with links to helpful “how-to” guides and letter templates in English and Spanish as well as yard signs and information posters.

Title: Love Leaves
Sponsoring Organization: Healthy Yards
Description: This website provides information on the benefits of mulch mowing, as well as step by step information on how to mulch leaves with a mower, with great photos.

Title: All About Leaf Blowers
Sponsoring Organization: Healthy Yards
Description: This website provides links to a wide variety of resources detailing the health and environmental harm of gas-powered leaf blowers. Not only are they a nuisance to residents and a health risk factor for operators, they also lead to soil degradation by eroding the ground (soil loss) and by preventing natural processes, such as leaf mulching, from occurring. Find the tools you need to bring attention on this matter to local authorities and legislators here. Many Westchester municipalities have enacted ordinances limiting use of gasoline-powered and other leaf blowers.