A tree that lives 200 years in the forest has an average urban life span of only 20 years. - Cass Turnbull
Step 1: Find the Perfect Spot
It's important to plant the right tree in the right place. Before you pick and buy a tree, try standing in your planned planting spot and think about these factors.
It's not the best idea to plant a tree under electrical lines. Cities usually require that any trees around these types of lines must have maximum heights of 25 to 30 feet.
Find out where your underground utilities are. Tree roots can cause costly damage to sewage and water lines. You can usually have the city send out someone to locate these for you.
Things like fire hydrants and road signs should also be factored into your planting spot. Tree branches can easily overgrow important road signage.
Root Space & Soil Quality
Make sure your tree will have the appropriate root space. Narrow sidewalk planting strips under five feet are too small for most trees. If this is your situation, it's usually better to plant the tree in your yard on the other side of the walkway.
Check out your soil quality and find out how fast it drains. Compacted clay soils are very common in urban planting areas. Try digging a 10" deep hole and fill it with water. Check to see how much the water has drained in 10 hours. If it drains less than one inch per hour, your soil is too slow draining for most trees. Many trees will drown and die within two years in poorly draining soils.
If you do have soil that is clay, compacted, and poor draining you will most likely want to plant in a different site. Here are some other solutions:
Amend a very large rooting zone by working a lot of organic matter into the top 12" of the soil.
Bring in high quality soil and build a large planting mound.
Set the tree higher than normal in the planting hole.
Do not work clay or saturated soils when planting, as this will destroy the soil structure.
Install positive drainage in the root-zone, if you are planting in a continuous planting strip. This would be like a "perf" pipe or a drain tile in gravel connected to a storm drain.
Plant a tree that is water tolerant like a Pin Oak or Red Maple.
Walks, Driveways, Windows, Cars
You'll need to imagine what your tree will look like fully grown. Trees that are planted close to sidewalks and structures need to meet special requirements. A wide spreading tree is not well suited for a narrow planting strip between a street and a sidewalk. Trucks and cars will hit the tree branches as they drive past and pedestrians will have to dodge branches growing over the sidewalk. The best place for a large, wide tree is usually in the middle of your yard.
Is there a special purpose for the tree(s)? Are they going to be used for summer shade, or as a windbreaker in the winter? Big, deciduous trees are great to plant on the south side of a house for shade. In fall those trees will shed their leaves and let in more light during the darker winter months. For winter windbreaks on the north side of a house, evergreen conifers do much better.
How much care are wanting to put into your tree? Will it be partially protected, well-watered, and mulched? Will it need to be pruned? Trees planted by parking lots or industrial lots will need to handle more of a battering and drought than in other areas.
Step 2: Pick the Perfect Tree
After you've locked down a good spot to plant your tree, it is time to pick out the perfect tree. It's best to shop at reputable nurseries and ask your local nursery-person for help. Be cautious of bargains as those trees might not be the healthiest.
Make sure the tree has a strong trunk with good tapering. The tree you pick needs to be able to stand up without any stakes supporting it.
Take a look at the trunk bark. Wounds and abrasions weaken the tree. Pick a tree that is free of these and make sure to look under tree wraps, as these sometimes hide wounds.
You'll want to make sure your new tree has a healthy root system. Make sure your tree has a one foot diameter of rootball for each inch of trunk diameter. Large trees in small pots will be much weaker plants.
Make sure there are no kinked or girdling roots. This can be harder to see since these are often hidden deep within the rootball.
It's best to do some research before buying a tree. Rule out any trees with bad reputations or that are invasive. You'll want to avoid any trees that are known for shedding, dropping limbs, raising sidewalks, and are susceptible to pests and diseases. Make sure to take into account the climate and area you live in. Trees that are great in some regions may not be suitable to yours.
Step 3: Start Digging
Your hole should be no deeper than the rootball on your tree. If it is deeper, the tree may sink and settle later on. Dig and loosen the surrounding soil to widen the hole outwards. Each inch you expand the hole outward will increase the probability of the tree's survival, especially if your soil is less than optimal. You'll want to make sure you at least have space to spread the roots of the tree.
You'll need to remove the pot, burlap, wire basket, or bag before planting. If the tree is in a peat pot or compostable pot, you'll also want to remove the pot. Compostable pots usually won't decompose fast enough and the tree will become root-bound.
It's important to not destroy the rootball during this process. Use knives, pruners, wire cutters, etc if necessary. You may need to use a knife to cut roots free of pot sides. Never let the rootball dry out or allow it to break.
The root flare or crown is where the roots diverge from the trunk.The root flare should be at soil level. If you plan to use mulch, it should be at mulch level instead. Use a stick or shovel handle to measure the rootball and compare it to the depth of the hole. Adjust your hole as needed.
Setting the Rootball
Once the hole is the right size, you'll want to spread out the rootball. Gently tease out the outer roots so that they make straight contact with the new soil. Make sure to cut off all circling, girdling, and damaged roots. Circling and girdling roots will weaken and eventually kill the tree later on.
Step 4: Plant
Plant the Tree
Use the unamended soil from when you dug the hole to gently fill in and plant the tree. Make sure that all of the roots are covered with soil and fill in any air pockets that you find. Air pockets will dry out roots. Be careful not to damage or crush any roots durning this process.
Soak your new tree with water. This will settle the soil. If more settling occurs afterwards, add more soil, but be careful not to compact any wet soil. It is critical to water a tree as soon as possible after it is planted.
Build a circular dam or basin with loose soil around the tree. This will help keep the water in the rootstock area and prevent run-off. It's important to deeply water new trees during the first few years so that their roots grow deep. Always make sure to water during droughts. 5 to 15 gallons of water a week is average.
Applying mulch around your new tree will help retain water, control weeds, and moderate soil temperature. Apply two to four inches of mulch, but never let it pile against the trunk. Make sure to brush back any mulch that is in contact with the trunk.
Only use staking as needed, as trees that rely heavily on staking often have weaker trunks and roots. The trees' slight movement is what makes them sturdy. Use them to hold up newly planted trees until the root system has established more, if the tree stands up just fine without them, skip them. Make sure to remove stakes and ties as soon as possible otherwise ties may damage the trunk.
If you do use stakes, use one or two 2x2 wood stakes. They should be in firm and undisturbed soil. Tie to the tree about one third up the trunk of the tree. Use flat tie material, like an inner tube, flat soaker garden hose, or other commercial products. Straight twine or wires will damage the trunk.