G ardens
Plant Portrait
Tsuga canadensis: Hemlock
Some of the oldest plants in the Dixon's living collection are our hemlocks. Although native to Tennessee, Memphis is well beyond their natural range. In fact these plants are common in the more mountainous eastern part of the state and not well suited to our hot, dry summers and heavy clay soil. Beautiful and graceful plants with pendulous branches that hang like draperies, the hemlocks add to the unique feel of the Dixon landscape. The largest ones here have reached a height of thirty-five feet. The hemlock is a conifer, which means it reproduces through cones in lieu of flowers. This plant is shade tolerant, which is not true of many of the conifers, and might explain why it is successful under the hardwood-tree canopy here at the Dixon. We have records dating back to 1944, when many of the hemlocks were planted here. Hugo Dixon paid $1.50 each for the trees from Cartwright’s Nursery. I suspect that these plants were recommended by his New England-dwelling sister Hope Crutchfield, who probably thought these Tennessee-native plants would grow here. We have many letters from his sister full of design and plant ideas. Although these plants are not common in the Mid-South, we have over forty growing here on the property today. Many forms of hemlocks exist. Some cultivars are minuscule, dwarf, only growing a few centimeters per year. Some are creeping plants that hug the ground; others have rounded forms; some have pendulous weeping forms; and others are white-tipped variegated forms. We are always on the lookout for new ones to add to our living collection. Unfortunately, a small insect from Asia called the woolly adelgid is having a huge impact on the native stand of hemlocks in the Appalachian Mountains. The cottony evidence of the insect’s presence is indicative that, without treatment, the plant is not long for this world. To date we have not had any evidence of this insect pest at the Dixon, but we are closely monitoring these plants. I suspect that our geographic isolation from the native stands and the fact that they are not a common landscape plant here has helped us remain pest free. Over time, our living hemlock collection may become even more significant as the wild populations decline rapidly. Dale Skaggs Director of Horticulture
12â€
J anuary F ebruary M arch 2013