Cooler days will surely get here soon, and their arrival is a great time to think about planting trees and shrubs. With the exception of a few species, fall-planted trees and shrubs will have a jump-start as their root growth continues throughout much of the winter.
Just like any other time of year, look for healthy, high-quality plants when making selections at your favorite local garden center. Knowledgeable nurserymen can provide recommendations, or Kansas State University offers two guides: “Recommended Trees for Northeast Kansas” and “Shade and Ornamental Trees.” These guides are available through K-State Research and Extension-Douglas County or through the K-State Research and Extension website, www.ksre.ksu.edu.
The most common tree I get asked about is one that is medium-sized, has great fall color, few insect and disease problems, leaves that blow away, and lacks messy fruit or seeds. I suppose that tree might exist somewhere, but in northeast Kansas I recommend prioritizing which of those attributes are most important. The K-State guides can help you determine which species is best for your individual situation.
Gardeners should also remember to look up and think about mature size when selecting trees and shrubs. Trees planted too close to power lines can be a major hindrance later in their life.
Large shrubs can also be a problem with power lines. For smaller shrubs, make sure to plant them far enough away from each other and from buildings to allow them to reach their full size potential.
When planting, the old recommendation was to plant at a depth that kept the soil level the same as it was in the container in which the tree or shrub was growing.
With shrubs, this is generally acceptable, but with trees we now understand this may be too deep. Picture a mature tree in your mind, and the way the base widens out at ground level. Compare this image to one of a utility pole, which is straight up and down.
Newly planted trees should also widen at the base. This may require removal of some soil from the mass of roots and soil that come on the tree. Try to set the tree at a depth so that uppermost horizontal root is at ground level or slightly above.
For container-grown trees and shrubs, loosen the lower portions of the mass of roots by cutting into them with pruners or a shovel. The loosening will stimulate root growth and help the plants recognize that they have more room to grow than in their previous containment.
Water immediately after planting to help settle soil around the roots and to provide moisture. Deep and infrequent watering is best, and continue to water over the winter while the ground remains unfrozen.
Apply a 2- to 3-inch layer of mulch to trees and shrubs to reduce temperature and moisture fluctuations. Keep mulch pulled away from the trunk or base of the plant to form a mulch doughnut rather than a mulch volcano.
— Jennifer Smith is the Horticulture Extension Agent for K-State Research and Extension in Douglas County. Contact her or an Extension Master Gardener with your gardening questions at 843-7058 or firstname.lastname@example.org.