With cooler temperatures and drier weather, you might think that the prime time to work outside has passed us by.
However, this is not the case, as gardeners and homeowners still have plenty of time to plant flowers, rework landscapes and plant trees in the fall just like they do in the spring and summer months. I’ve included below a few of the more commonly- asked questions that I’ve received during this time of the year:
Q: I want to plant several maple trees that you talked about last week that will provide some shade and pretty fall color. But how deep should I dig the hole?
A: This is a very important question. Most newly-planted trees and shrubs die because of improper planting techniques. I can’t stress this enough – plant a tree correctly and it will succeed more than likely. We sometimes set the root balls of trees and shrubs too high in the ground and they dry out and later die. Or we more often place trees and shrubs too deeply in the planting hole where they then usually develop root or lower stem rots and slowly die over time.
In the past, we thought trees produced a very deep root system that grew primarily within the drip line. The drip line is that imaginary boundary of area that extends from the trunk out to the outer tips of the branches.
More recent research has shown, however, that many trees have a heavy concentration of horizontally spreading roots that grow in the top 2 to 3 feet of the soil. Studies also show that about 60% of the roots spread out beyond the drip line.
Thus, tree experts are saying it is most crucial to plant trees in holes that are wide rather than overly deep. A good rule of thumb to remember when planting trees is to always dig the hole at least twice the width and one and one a half times the depth of the root ball.
Q: How can I tell where the top of the root ball is so as not to plant the tree too high or too deep in the ground?
A: To get a good idea of where to position the root ball in the planting hole, you should first remove any pins or twine that is holding the burlap tightly in place near the soil-trunk line on balled-and-burlapped trees.
Then carefully peal back the burlap from the root ball and look for the trunk flare. This is the area where the trunk meets the large roots. If the tree is in a container, then gently remove it from the container being careful not to fracture the root ball.
Again, look for the root flare where the stem of the tree meets the large roots. Now measure the distance from the trunk flare to the bottom of the root ball. This measure indicates the precise depth of the planting hole.
When you place the root ball in the hole, the base of the trunk flare should be level with the soil surface. After setting the tree in place, check to be sure that you did not plant too deeply or too high by laying your shovel handle across the planting hole. The handle should be level with the surrounding ground or terrain when placed over the top of the root ball.
Q: If I plant my tree deep in the ground, won’t
this help it better survive heat and dry weather?
A: No. In fact, planting too deeply almost always results in stunted growth or death of the tree.
Trees that are planted too deeply produce roots that are very likely to become diseased due to poor water and air movement in the soil.
As time progresses, root systems that are set too deeply begin to decline and the tree itself may later die. Always plant trees at grade for best root growth.
Q: I saw landscape workers planting trees in my office complex and noticed that they built a soil ring around the trunk and then mulched the trees with about a foot pine straw. Is this good?
A: It is always a good idea to build a “soil ring” around newly- set tress.
Use leftover soil from the planting hole to build a ring 2 to 3 inches high that is located several feet away from the trunk.
A soil ring helps to capture and hold water so it is then funneled to the roots of newly-planted trees rather than running off and becoming unavailable. Soil rings should be left in place for about a year. After that time they should be leveled out as the tree’s roots begin to grow and expand outward. It is also very important to place a 4 to 6 inch layer of mulch around newly-planted trees.
Mulch materials, such as pine straw or pine bark, help the soil to retain moisture and also help to prevent soil erosion and unwanted weed growth.
Place mulch on the ground around the tree starting 3 inches or so away from the trunk and out to just under the drip line. Using too much mulch, however, may do more harm than good. Using more than 6 inches may actually cause the ground to stay soggy and thus prevent proper air movement to the root zone. Wet, poorly-drained soils often result in the development of root rots. And one last step, always thoroughly water-in newly-set trees just after planting to insure that they get off to a good start.
For more information on planting trees, contact me at the Bryan County Extension office at 912653-2231 or uge3029uga.edu.