Are you concerned about the future of our planet? Plant a tree! Trees can help keep us and the planet healthy. And autumn is a perfect time to add a tree to your landscape.

Benefits of trees

 

Trees help us breathe

Trees produce oxygen. Without trees, life could not continue. Trees absorb odors and pollutants and filter particulates out of the air by trapping them on their leaves and bark. also remove airborne particles from the air and reduce smog.

Trees combat climate change

Trees absorb carbon dioxide, removing and storing the carbon while releasing oxygen back into the air. In one year, an acre of mature trees absorbs the same amount of CO2 produced when you drive your car 26,000 miles.

Trees reduce runoff and help keep our water clean

Trees absorb water, reducing the stress on storm drains and the risk of flooding. An adult tree can absorb between 50-100 gallons of water from the ground each year. Trees also act as natural filters, removing pollutants. The roots reduce erosion and break up soil to allow for the recharge of water tables.

Trees provide shelter and shade

Trees cool the air and help slow water evaporation from soil. They can reduce sunlight entering the house, keeping rooms cooler. The evaporation from one tree can produce the cooling effect of ten room-size air conditioners, reducing energy needs.

Trees encourage wildlife

Trees provide homes and food sources for birds, insects and small mammals. Animal populations worldwide have declined almost 70 percent in the last 50 years.

Trees make us feel better

Researchers have repeatedly found that exposure to nature improves our mental and physical health. Trees and green environments make us more relaxed and reduce stress. Patients with views of trees out their windows heal faster and with less complications.

Trees provide food

An apple tree can yield up to 15-20 bushels of fruit per year and can be planted on the tiniest urban lot.

Trees increase the value of homes and businesses

A well-planted landscape can raise property values by as much as 15 percent. A business district with more trees and landscaping attracts more business and slows traffic.

Why to plant a tree in fall

Planting trees in autumn has many benefits.

• The tree will have an extra growing season to establish strong roots. This will make it easier for the tree to adjust to the stress of summer heat and drought.
• Fall and winter rains water the tree, and cooler temperatures mean less evaporation, so you have to do less watering.
• Cooler, cloudier weather means the tree won’t be subject to drought, high heat or sun scorch.
• The condition of the soil is better. The soil is still warm and not quite as damp as spring, when it has been raining for months.

Choosing the right tree

You will need to do some research to find the right tree for the right area of your yard. You will want to consider:

• Reasons for planting: Would you like to shade your house in the summer or to create habitat for birds? Are you looking to provide some seasonal interest or frame your view? Select the appropriate tree to help you achieve your goal.
• Sunshine: Is the planting location sunny, shady or partly shady? Will it get morning or afternoon sun?
• Size of mature tree: How large will the tree grow? Does the chosen location have enough room? Will it be too close to your house or other structure as it grows? Will it encroach on power lines?
• Soil: What type of soil do you have? How well does it drain?
• Pests: Is the tree susceptible to insects or diseases?
• Hassle factor: How much maintenance will the tree need to look good over time?

You may want to stroll through your local nursery to look at their selection of trees. And ask the nursery staff: they would love to help you make the right choice.

Here are some sources to help you choose your tree.

• 145 recommended trees for our local climate and conditions, Great Plant Picks
• Best Trees for Seattle, Association of Professional Landscape Designers Washington
• Ten trees and shrubs for a small, city garden, Swansons Nursery
• 19 species of native trees, King County

Selecting a good specimen

Planting healthy trees starts with selecting a healthy tree from the nursery. Here are tips on what to look for from the City of Seattle.

• A strong, well-developed single leader (trunk).
• Good branching structure, with branches well distributed around the trunk. The branches should be considerably smaller in diameter than the main trunk.
• Ideal spacing between branches, at least 8–12″ for most species.
• No large circling roots visible on the surface of the container. Since container trees are often planted too deeply in their container, you may want to dig down and look for large circling roots under the soil.
• Avoid trees with lots of weeds or moss growing on the surface of the soil. This can indicate the tree has been in its pot for a long time and may be root bound.
• If the tree still has its leaves, examine the leaves and make sure they look healthy. Remember if it is fall, it is normal to see browning or yellowing leaves.
• Bright, healthy looking bark.
• A trunk and limbs free of insects, wounds or mechanical injury.
• A visible trunk flare. Since container trees are often planted too deeply, you will likely need to dig down to locate the trunk flare, which is where the first major root extends from the trunk.

How to plant a tree

Here are tips on how to plant a tree (most of the points below are from the City of Seattle).

1. Call Before You Dig. Call 811 or submit an online dig ticket at least two days before planting. Make sure to plant your tree at least five feet away from any marked utility lines.

2. Remove the tree from the pot. Gently roll the pot from side to side on the ground then tip it upside down. Be sure to carry/move the tree by handling the pot, not the tree’s trunk.

3. Locate the trunk flare. Remove any excess soil piled on top of the root flare. The trunk flare is the area where the first major roots extend out from the trunk. Once planted, the trunk flare should sit just above the top of the soil.

4. Examine the roots. Roots that are circling should be redirected to grow out into the soil. If this is not possible, it is better to cut a root than to allow it to continue growing in a circular fashion. Circling roots will stunt the growth of the tree and can eventually lead to the tree’s death. Read about how to deal with circling roots.

5. Dig a shallow, wide planting hole. Dig the hole only as deep as the root ball and about 2-3 times as wide. Do not loosen the soil at the bottom of the hole, which will cause the tree to settle over time.

6. Remove any bamboo stakes or tags still attached to the tree. These will not help support your new tree, and will only cause harm to your tree down the road.

7. Place your tree into the hole and orient. Think about where you want the main branches to point. Be sure the trunk flare is above ground. A buried trunk flare will lead to rotting over time, compromising the health and safety of your tree.

8. Fill in the hole using the native soil and pack in firmly. Avoid putting amendments such as fertilizers and compost in the hole. These can actually harm your tree. Amending is best done with a thin layer of compost as a top dressing.

Don’t forget to water and mulch!

9. Water your tree deeply right after planting. You may want to build a berm around the tree so there is a container to absorb water. See our video, How to Plant and Water a New Plant.

10. Mulch with wood chips to help retain moisture in the soil. Add a few inches of mulch in a ring around the base of your tree. But don’t pile it against the trunk; leave a few inches of space. See our video How to Use Mulch Around Trees and Shrubs.

You should continue to water during the fall and winter season. Give your new tree an inch of water each week. Deep watering is much more effective than shallow watering and will help the tree to develop deep roots.

You might consider buying a Tree Gator, is a large bag that holds 15 gallons or more of water and releases it slowly. This makes it easier to ensure you are watering your tree deeply. See our video Tree Gators: How to Water a New Tree.

Your tree will not do well without enough water, but it is also harmful to overwater a tree. You can use a trowel or soil probe to see if the soil is dry. Insert it into the ground to a depth of two inches, loosen the hole, and then touch the soil with your finger. If it is moist to the touch, your tree does not need water.

You will want to continue to water your new tree regularly for the first two or three growing seasons. This will help the tree establish strong and deep roots.

Stake only if necessary

Stakes can rub and cause damage to the bark and branches. Stake your tree only if the tree cannot remain straight without support. If you do decide to stake, use broad, flexible tree ties to attach the tree the stake.

Find the lowest point on the trunk where the tree can be held upright. This will let the trunk move with the wind and build stronger roots. Use broad, flexible ties and keep the ties loose on the trunk to avoid girdling. Remove stakes after one year. Learn more about proper staking here.

More information

• Selecting and Planting Trees, The Morton Arboretum
• Tree Care Tips & Techniques, Arbor Day Foundation
• Tree Selection and Placement, Trees Are Good
• Trees 101, King County