How to Plant Trees
Plant Trees for the Future
We plant trees for the future. Tree planting is simple and the result can be a legacy for the future. Many trees take nearly a generation to fully mature.
Rules for Planting
There are not a lot of rules to correct planting, but there is some common sense required. Planting that goes against the way trees grow in nature can actually kill a tree.
The most common error is planting too deeply. Above ground parts of tree (trunk and branches) should be above the surface of the ground and below ground parts (roots) go under the soil. This is pretty easy, but its amazing how many people plant trees too deep. When the trunk of the tree is below the surface of the soil it sufficates because it has to be in the air. It is easy to tell where the roots end and the trunk begins on most trees. Often there is a changes in color or texture, but the easiest clue is that the trunk flares outward as it attaches to the roots. The flared portion goes ABOVE the soil line.
Look at the root system before planting. Potted trees are sometimes rootbound, meaning that the pot is so filled with roots that there is virtually no soil and the roots are a solid tangle. If planted without doing anything but putting it in the hole, the roots may continue to grow round and round in the panting hole and eventually sufficate itself as the roots grow. Take a sharp spade or a knive and make verticle slices through the edges of the potbound root mass, cutting it so that any encircling habit it may have begun is stopped.
When a tree or shrub is bare root, spread the roots in all directions. Don't just stuff it in the hole. Make sure the roots arre not exposed to air for more than a few minutes. Roots must be kept from drying out, especially the smallest roots, as they die if they become dry.
Amendments
In the past, recommendations were to add all sorts of amendments to the soil. The hole was filled with peat moss, potting soil, manure or other additives with the idea that it would help the tree to grow better if it had a nice start with a good soil mixture.
Careful observations have shown that trees planted in Nebraska clay that had amendments like peat and extra compost put in the hole did not do as well as trees planted directly in the clay they were to grow in. In some cases the tree roots seemed to enjoy the amendments so much that they stayed in the hole like it was a flower pot in the clay and never ventured out in the native soil. If this happens the tree may become girdled because the roots wrap around in the hole and eventually chokes itself.
Tough love seems to be the solution. Do not add amendments to the hole. However if we look at nature, the upper few inches are generally richer in organic matter and called topsoil. Trees have many feeder toots near the surface. We can replicate this by adding compost or other amendments to the upper six or so inches where trees and shrubs are planted.
The ideal situation is to make plantings in beds. This means that instead of a single tree or shrub, plant in groupings. This is the way most plants grow in nature anyway, in communities. Make sure to choose plants that will do well in similar conditions or that will thrive when matured together. Prepare the entire area of the grouping by putting down 2 to 3 inches of compost and then spading or rototilling in to a depth of five or 6 inches deep.
Size of hole
Dig a hole wide enough for the roots to spread out. For a potted or balled and burlapped tree, make the hole 2-3 times as wide as the width as the pot, but not deeper. Make the hole wider so the clay is loosened up a bit where the roots will be growing outward in the future. Make it about 2 inches or so shallower than the depth of the soil in the pot is often considered better. It will not hurt if the top of the pot or ball is a couple inches above the surface.
You may have noticed noticed that many nurseries are in the habit of planting trees several inches higher than soil level. This is not because it is the way a tree would grow on its own, but rather for self preservation to protect their guarantee. The tree is more likely to survive the over watering that is common by many people who think that grass needs lots of water in the summer. When the hole is less deep than the soil in the pot and the area is watered too much, then the tree will not drown.
Watering
After backfilling the soil that was removed from the planting hole and putting it around the roots of the new tree or shurb, get out the garden hose. There are air pockets in the soil that must be removed so that the soil is all settled around the roots and not air in the pockets will dry out the roots, which could cause some of them to die. Push the end of the hose down into the soil around the rootball and turn on the water very low. Let the water seep around the root zone so that soil settles into every space around the roots. When the water fills that side of the tree, move to the other side. For larger trees, do this is several places. Sloshal* the hose in the wet soil to close off the hole made from the hose. (*Sloshal is a word I made up, meaning to move the hose up and down and sideways in the muddy water so that the mud closes over the hole made from pushing the hose into the soil.)
When and how often should new trees be watered?
Water is a major concern for most people who plant a tree.
In Nebraska we cannot count on rain during the heat of the summer and some trees, especially non-natives, can become so stressed from lack of water that they die. Too much water can drown a tree. The popularity of sprinkler systems is the greatest cause to early death of trees and other landscape plants in Nebraska, simply because people apply too much water.
Newly planted trees need more water than established trees. Once roots have grown into the soil and become established, most trees will survive on natural rainfall, unless there is a drought.
Amount of water
The amount of water to give a newly planted tree depends upon a number of factors.
- Size of the tree
- Condition of the roots
- Size of the rootball
- Species of tree
- Air temperature and humidity
- Wind
- Amount and type of mulch
- Soil type
Many Variables, But Do Not Water Too Much
With so many variables, it is obvious that there is no magic formula to tell how much to water. Newly planted trees should not dry out, yet if watered so much that the soil is water-logged so that all the air spaces in the soil are filled with water, the tree will die from drowning.
1. Smaller caliper trees will need less water than larger trees with a larger canopy to support.
A 1-inch diameter tree trunk, measured about 6-8 inches from the bottom, should get one to two gallons of water about every other day when the weather is 75-80 degrees F.or less in the summer. As the temperature rises, newly planted trees are more likely to need water.
Use the moisture touch test. During hot weather, the soil dries out faster than in cool. Your index finger is one of the best testing devices for moisture you can use. Dig down about an inch in the soil and feel how cool the sol feels. If there is moisture in the soil it will feel cool to the touch. If the soil feels the same as the air, the tree needs water.
A larger the rootball will require more water than a smaller tree. Often larger trees will have had a considerable amount of their roots removed so although they seem larger and more robust, are really needing attention to watering to be sure they get enough water, but not so much they drown.
It is a good idea to know the water requirements of the tree. Some trees can survive with more water than others. The greatest killer of trees in the modern landscape is the sprinkler system. Trees generally will not do well with as much water as many people abuse their lawns with. Evergreens, in particular do not tolerate over watering.
How much water is enough?
Most trees only need a few gallons a week. Larger trees need more than smaller, but putting the sprinkler on for long periods is most likely to suffocate the tree. Water so the soil all around the tree and past the area where it was planted is moistened. A sprinkling can or 5-gallon bucket is closer to the amount needed for most trees.
