Tree Pinus sylvestris [Scotch Pine] Effective as a screen with pruning. Tolerant of fairly dry soils, but not a good specimen in shade or on wet soils. Sphaeropsis, nematodes, and pine wilt fungus are serious problems; not recommended by Morton Arboretum.
Shrub/Tree Platycladus orientalis [Oriental Arborvitae] Best in at least fairly moist soils, and with fairly high humidity. Habit tends toward becoming thinner (open) with age. Subject to "winter-burn" near the edge of its useful range. Certain forms provide very positive accent, but can be over-used. Bagworms can also be a problem.
Tree Pseudolarix amabilis [Golden Larch] No serious diseases. Should be protected from too much wind.
Tree Pseudotsuga menziesii [Douglas Fir] A highly variable species, in cold and drought hardiness, color, and form. For use in the Midwest, select the hardiest available forms. Prefers atmospheric moisture. Historically, has been an important timber tree in the West.
Tree Pseudotsuga menziesii 'Fastigiata' [Columnar Douglas Fir] Pseudotsuga menziesii is a highly variable species, in cold and drought hardiness, color, and form. For use in the Midwest, select the hardiest available forms. Prefers atmospheric moisture. Historically, has been an important timber tree in the West. 'Fastigiata' is a dense, columnar cultivar with distinctly upright branches.
Tree Quercus × 'Crimschmidt' [sold as Crimson Spire™] [Crimson Spire Oak] The Crimson Spire Oak is notable for its powdery mildew resistance and reddish fall color that it gained from its White Oak parent, in addition to the dense, strong, vertical, columnar form, and tolerance to drought and urban conditions gained from its Fastigiate English Oak parent.
Tree Quercus robur 'Fastigiata' [Columnar English Oak] The tightly columnar 'Fastigiata' provides a strong vertical accent, and is far more popular in the Midwest than the straight species. Powdery mildew on the leaves can be a significant problem. Seed propagated 80-90% true to type, thus variation can also be a problem.
Tree Quercus × warei 'Long' [sold as Regal Prince®] [Regal Prince Oak] The Regal Prince Oak is notable for its resistance to powdery mildew and borers, strong vertical, columnar form, and tolerance to wind and ice. Holds its dense, fastigiate form into old age.
Shrub/Tree InvasiveThis plant is considered invasive Rhamnus cathartica [Common Buckthorn] Tolerates most sites. Dioecious. Very invasive, by the seeds that birds love to eat; probably best to refrain from planting this species in the landscape. Susceptible to rusts (Puccinia coronata), that also attacks oats (in oat growing areas, buckthorn eradication is recommended). The bark, leaves, and fruit were once used in purgatives, thus one of this plant's common names, "Purging Buckthorn".
Shrub Rhododendron catawbiense [Catawba Rhododendron] The Catawba Rhododendron is considered to be one of the hardiest rhododendron species. Beautiful plant when it is used in mass. Flower color of the species does not combine well with some other flower colors. Flower color bleaches out in high pH. Subject to winter burning of foliage in exposed sites near the limits of its range. Both flowers and foliage are of equal value in the landscape. Cultivars are usually less hardy than species.…
