Author: Margot McMahon, Yale Class of ‘84
Location: Chicago, IL

Personal Action

It’s easy to become a tree steward! Basic activities include watering trees, adding mulch and soil, and removing weeds and litter; as well as advanced activities such as installing a tree guard, expanding tree beds, and installing or removing stone or brick pavers.

Environmental Impact

Chicago Regional Tree Initiative (CRTI) will plant 22 million saplings to replace and protect its regional forest. Trees clean the air and water, capture carbon, reduce flooding, improve our quality of life and the value of our homes, create habitat for wildlife, and provide significant health benefits.

The Chicago Region Trees Initiative describes its intent: “(CRTI) is a partnership for coordinated action on key issues facing trees. It is the largest such initiative in the country, with leading organizations and agencies from across the seven-county metropolitan region working together. CRTI is leveraging funding, knowledge, skills, and expertise to build a healthier, more diverse regional forest.

How to Get Involved: Basic Tree Care Activities

Tree Care Tips: Watering

For the first few years, watering is the most important thing you can do for your tree. It may also be the hardest task to accomplish. Getting water from the source to the tree can be a challenge. Also, because of pollution and compression due to foot traffic, city soil has difficulty absorbing water. This means that you need to cultivate or loosen the soil so that the water can reach the tree’s roots. There are a number of different tools and techniques available to help your watering efforts.

Tools You Can Use

• 5-gallon bucket
• hand cultivator
• hose
• Treegator & Treegator Jr.
• hydrant adaptor
• trash-can

Suggestions for Street Tree Watering

• Poke small holes at the bottom of a large trash can. Fill it with 15-20 gallons of water and leave the trash can next to the tree overnight.
• Ask building maintenance staff to water trees while they are hosing off sidewalks.
• Ask street vendors and merchants to dump water from their containers (coolers with melted ice or flower buckets) into nearby tree pits at the end of the day.
• Make sure water with detergent or bleach is dumped into the gutter, not the tree pit.

Tree Care Tips: Weeds and Weeding

Weeding your site, although not as important as watering, is still essential. Both street trees and green streets live in very small spaces that provide limited amounts of soil and nutrients. Weeds are fast-growing and fast-reproducing plants that tend to dominate space and sap resources from the plants intended for the site. If weeds are left untended, they will ultimately kill some plants and stress others. Thus, weeds should be removed from green streets and street tree pits as frequently as possible.

Tools You Can Use

• gloves
• trowels
• garbage bags

Guidelines

• Identify the plant as a weed.Visit Rutgers University’s Weed Gallery for help in weed identification.
• Wear gloves. When removing weeds, take out the entire root system. Leaving behind some of the plant will allow the weed to grow back. Use trowels or weeders to dig out stubborn roots. 
• Put the plant and its roots into a garbage bag, or compost it. 
• Dispose of trash properly. 
• Do not use a weed whacker or lawn mower next to a tree. They can damage the bark and weaken a tree. 
• Reduce herbicide use near a tree and in surrounding lawn. 
• When weeding, be on the lookout for poison ivy and any hazardous trash in the soil. 
• Try to remove weeds before they flower and spread seeds. 
• Weeds are easier to pull when the ground is wet. If the ground is dry and the weeds are stubborn, soak the ground with water first.
• If you find white wood aster growing under your tree, consider keeping it rather than pulling it. It is a native wildflower that will eventually form an attractive ring around the tree. Plus, it will produce pretty white flowers for several weeks each fall.

Tree Care Tips: Mulch, Compost, Soil Maintenance

Mulch is roughly ground up wood from other trees, and can act as both a protective buffer and nutrient-rich layer for a young street tree. Spreading a 3-inch layer of mulch on a street tree bed can help prevent soil from becoming hard and compacted, making it easier for the tree’s roots to take in air and water.

Mulch is also a great retainer of moisture, and can help prevent the soil from becoming extremely dry during a hot summer drought or high winter wind. In addition, spreading a 1-inch layer of compost, decomposed food, and yard clippings before placing the mulch will allow the soil to better hold air and water, drain more efficiently, and provide a nutrient reserve that the tree can feed on.

Too much mulch, compost, or building a mulch ‘volcano’ around the base of the trunk can be harmful for the tree. Before any additions to the tree bed are made, it’s important to aerate the soil. See how it’s done below!

Tools You Can Use

• Gloves
• Cultivator
• Rake
• Bucket or Wheelbarrow

You can obtain mulch through stewardship of other street tree care workshops or your park district. You can buy mulch at gardening stores like Home Depot.

Guidelines

• To aerate the soil of your tree bed, take your hand cultivator and rough up the dirt 1-inch to 3-inches down. This will break up the compacted soil and allow more oxygen to get down to the roots.
• Spread compost to cover the whole street tree bed. The layer should be no more than 2 inches high, and should not be touching the trunk of the tree. You should be able to fit your fist between the compost and the trunk.
• Spread mulch to cover the whole street tree bed. The layer should be no more than 3 inches and should not be touching the trunk of the tree. You should be able to fit your fist between the compost and the trunk.
• If you do not have enough mulch to cover the whole bed, build a ring of mulch 3 inches away from the tree trunk. You should be able to see the roots at the base of the tree taper off into the soil.
• Do not build a mulch volcano. A ‘mulch volcano’ is what happens when mulch is piled high and close to the tree trunk. This does not allow the roots and lower part of the trunk to interact with the atmosphere and encourages ‘girdling,’ a root problem that eventually causes the tree to strangle itself. Mulch volcanoes also create rot by building up too much moisture against the tree trunk.
• Although mulch can be applied at any time of year, spring and fall are best for young trees to help retain moisture and prepare for extreme seasonal temperatures.
• If you do not compost at your home or workplace, you can obtain compost from your local park district