Q. A tree company (not from Jefferson City) advised me to "top" my tree? Should this be done, and under what circumstances?
A. Topping of trees is strongly discouraged by reputable sources, such as the International Society of Arboriculture. For this answer, a publication from Indiana's Purdue University (Department of Forestry and Natural Resources) was used, titled "What's Wrong with Topping Trees?" It cites no circumstances in which topping is advised. It says this practice stems from homeowners' concerns for trees reaching heights they consider unsafe. They fear a strong wind might blow these large trees over - a fear largely unjustified, for the extensive root system of a healthy tree, left undisturbed, provides adequate support for the tree.
Topping is the drastic removal or cutting back of large branches in mature trees. The tree is sheared like a hedge, and the main branches are cut to stubs. Topping is also referred to as heading, stubbing or dehorning. The publication mentions eight reasons to not top. They are starvation (from leaf removal), shock, increased insect/disease pressure (large open wounds), weak limbs (that grow afterwards), rapid new growth (which may get even taller), ugliness and cost. For a tree service to promote this, they are acting unethically. The campaign against "topping" is a couple of decades old. This company should know better and is just promoting this to make money from unwary or fearful property owners. There are a number of companies in and around Jefferson City doing a quality job. If you have concerns, consider using one that retains a certified arborist.
Q. My various perennials like peonies, hostas and irises are starting to go dormant. Is there anything I should do?
A. In the fall, after freezing temperatures have killed annual flowers and turned perennial foliage brown, remove dead leaves, stems and spent flowers. These materials often harbor insects and disease-causing organisms. Plants such as ornamental grasses and perennials with sturdy stems that stand up well may be left in place to provide winter interest to the landscape. In late winter, cut such plants back to ground level to prepare for new growth.
Apply several inches of winter mulch to tender perennials after the soil temperature drops enough to develop a frozen crust. Winter mulch will insulate the soil to help prevent damage to tender roots. It also helps reduce damage from alternating freeze-thaw cycles that can heave roots out of the ground. The following perennials are advised to receive winter mulch: Bellflower, Geum (Avens), Poppy (Oriental), Red-hot Poker (Tritoma), Stoke's aster, and Thrift.
More detail can be found in two MU Extension publications: "Flowering Perennials: Characteristics and Culture" and "Establishment and Care of Herbaceous Ornamentals."
Q. When is the best time of the year to take a soil sample?
A. The fall. This is because the two amendments used to change the pH of the soil take about six months to take full effect. So if you are advised to apply lime (to raise the pH, which reduces acidity) or sulfur (to lower the pH) this change can occur when plants are relatively inactive, if not completely dormant. Our extension center receives hundreds of soil samples annually. We send the samples to University of Missouri's Columbia soil lab and get the results, or report, about a week later. We can help you to understand the report and its recommendations. The reports are retained on a database that we can access for several years afterward, in case you misplace it. Samples can be brought to our extension center on business days from 8 a.m. to 4:30 p.m., and the cost is $16 per sample. We have a special tool, or probe, which we can loan out to make it easier. It is a $16 deposit to borrow a soil-sampling probe, and we can give you a collection box at that time.