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Plant trees right the first time

I hope that the columns of the past few weeks have convinced you that now is an excellent time to establish new trees and shrubs in your landscape. Container-grown or balled-and-burlapped trees have plenty of time to become well-established before winter comes.

Just dropping trees in the ground is not going to ensure their success, so I am sharing some of the best ideas to help you establish the plants in your landscape. Keep in mind that the advice contained here might differ from some long-held "old spouse's tales" of how things should be done.

Start by making your tree selection. No, I do not mean go buy a tree. I mean do research to decide which tree is going to establish, grow and thrive in your landscape without overgrowing the area. Remember you are going to share your space with these trees for many decades so make your decisions carefully.

Once you decide on the tree you want, go shopping. Many nurseries offer specials in the fall because they would rather turn their money and their stock before spring. Remember that the price is not the only consideration. Make certain to select those that will survive our climatic and soil conditions.

Look for healthy leaf color. Some trees will be getting fall color but that is perfectly acceptable. Avoid plants that are weak and spindly or too tall for their container. Examine the trunk of the tree and avoid any tree that is scarred and wounded.

Most shade trees grow best with a strong central trunk and branches attached at near right angles. Tree branches attached with narrow angles (close to the trunk) often break down. Tree form varies with the species of the tree so look at several specimens to determine what form yours should show.

Like many other things in life, it is often what you cannot see that creates the problems. A plant that has been sitting on display all summer may be root-bound or have other defects. Check out the root ball, if you can, to see whether the roots are growing normally or wrapping around in a stranglehold.

If the tree has serious root deformities, do not buy it. Some problems will just get worse over time and might eventually cause the plant to die. J roots are caused by jamming small seedlings in pots during the propagation process. This troublesome and nonreversible defect might destroy your tree many years later.

Girdling roots are another very common problem with plants growing in containers. Roots that have started to grow around the trunk will continue doing so, even when the root ball is unwrapped or removed from the container. If the trees are planted correctly, this problem is correctable.

The tree trunk and the tree roots never change position relative to each other. As the tree grows, it becomes suicidal. The trunk continues to grow in diameter and the roots also get bigger around. Eventually the roots that encircle the trunk get so thick and the trunk becomes so enlarged the tree strangles itself.

To prevent girdling roots, take a sharp knife and cut through the outside of the root ball in three or four places. The cuts do not need to be deep — they just need to cut the fine roots that are growing around the pot. This prevents roots from circling and growing until they strangle and kill the trees.

Soil preparation is another important part of tree survival. Break up the soil until the clods are no smaller than a grape and no larger than an egg. Remove large rocks and any construction debris you might find. If your soil is not good quality with too much sand or clay, add compost, peat moss or other amendments over the entire area where you will plant the tree.

Previously, many erroneous publications recommended replacing the soil with various types of organic matter. That is not a good idea because it then creates a natural flowerpot so that the roots only grow in that soil and never move into the native soil. That develops a very small unnatural root system and that affects the long-term growth of the tree.

After preparing the soil, it is time to dig the hole. When I was young, I always heard "You should not dig a dollar hole for a $10 dollar tree." Adjusting for inflation, it now reads, "You should not dig a $10 dollar hole for a $100 tree."

What that means is that the hole needs to fit the tree. Older textbooks recommended excavating a very deep hole and then backfilling the bottom of the hole with amended soils. When that happened, the tree root ball was placed on unsettled soil. As it compacted, the tree sank and was buried too deeply.

When the bark on the trunk of a tree is buried, it stays wet and is not exposed to oxygen. This often rots the base of the tree and kills the tree. To aggravate the problem further, the sunken hole collects additional water that helps make the problem much worse.

Dig the planting hole about one inch less than the depth of the root ball of your tree. That places the tree on firm soil that will not settle. Dig the hole several times wider than the root ball so when the tree roots start to grow out, they can spread without restriction.

Some trees have taproots, but do not be concerned about them when transplanting your trees. In production nurseries, the taproots are removed when they are root pruned. Consequently, the roots on all trees need to spread out and not go down.

The biggest controversy is what to do about what is holding the root ball together. Some root-ball packing material is almost indestructible so remove wire, plastic, fiberglass, or anything else that will not rot quickly that might interfere with normal root or trunk growth.

Having said that, remember the pots, wire baskets and burlap are to hold the root ball together and prevent it from breaking. Remember a broken root ball usually means a dead tree so handle them carefully to avoid destroying the plant.

Balled and burlapped trees with wire baskets should be carefully set into the planting hole using the wire baskets. After backfilling about a third of the way up the root ball, carefully cut away any wires or strings on top and then cut away any treated burlap.

Remove container stock from the pot very carefully and place it in the hole. Then backfill around the root ball while you water it in. Avoid stomping or otherwise compacting the soil when planting. Water to keep the soil moist, but do not overwater.

Keep an eye on the rainfall and supplement it as needed. Keep in mind that temperatures are cooler and that the trees are losing their leaves now, so they need less water in the fall. Drought-stressed plants are much more likely to suffer winter damage but overwatered trees quickly develop root rot.

Plant them right and give them the care they need. Trees can grow for centuries but improper planting will send them to an early grave. Take the time to do it right the first time.


Larry Sagers is the Horticulture Specialist for Utah State University Extension at Thanksgiving Point.