Gardening: The ABCs of trees
Probably the biggest mistake homeowners and landscapers make is planting a tree too deep.
A properly planted tree should have its root flares, the widened area between the trunk and the roots partially exposed above the surface of the soil. If the tree trunk looks like a lollipop stick stuck in the soil, the tree has been planted too deeply. Deep planting reduces the amount of oxygen available to the roots, which is needed for respiration need for new root growth and nutrient uptake.
Deep planting also encourages surface rooting and girdling roots that can shorten the life of the tree down the road. It’s estimated the average life of an urban tree today is 10 to 15 years. Google photos of root flares for pictures.
If you have inherited a tree that is planted too deep all is not lost. A trained tree doctor, a certified arborist can free those root flares without harming the tree by using an air spade to blow away the soil. If caught soon enough, girdling roots can also be removed by an arborist. To find a professional in your area go to www.tcia.org and enter your zip code.
According to Bert Craig, from the Michigan State University Department of Horticulture and Forestry, the first two years of care after planting are critical for a tree’s long-term survival and water stress is the No. 1 factor. If it doesn’t rain, Craig recommends a newly planted tree should be watered well every two weeks. In most cases in ground irrigation system are geared watering lawns and do not provide enough water for newly planted trees. In hot dry weather such as we have suffered this summer I would water a newly planted tree weekly.
Proper mulching is another key to success. A 3- to 4-inch layer of good organic mulch, such as tub ground tree trimmings, will help hold moisture in the soil and protect tender new roots. More is not better when it comes to mulching so take care not to overdue. Measure, don’t guesstimate. Too deep of a layer will encourage the tree roots to grow up into the mulch, and they are killed by heat and drought in summer and frost in winter. Also be sure the leave a 6-inch space between the mulch layer and the tree trunk to prevent damage from disease, pests and insects.
Fertilizing can be done a year after planting, in late winter or early spring. An organic product such as Espoma Tree Tone is a good choice.
Nancy Szerlag is a master gardener and a Metro Detroit freelance writer. Her column appears Fridays in Homestyle. To ask her a question go to Yardener.com and click on Ask Nancy. You can also read her previous columns at detroitnews.com/homestyle.