Here are some attributes of three under-used landscape trees. All can be seen in the arboretum at the Department of Horticulture/Landscape Architecture Plant Environmental Research Center, located at the southwest corner of the Colorado State University campus, or at the Center Avenue woody plant research site located directly north of the gardens on Spring Creek, City of Fort Collins.
Lacebark Pine Pinus bungeana
Lacebark pine has attractive exfoliating bark in patches of green and brown which makes it a good single or multi-stem specimen tree.Needles are medium to dark green about 3 inches long. It tolerates moderately alkaline soils and is hardy to zone 4 to 5. This tree will reach a mature height of about 30, with a 15 foot width.
Harvest Gold® Linden Tilia x ‘Harvest Gold’
This hybrid of littleleaf and Mongolian linden develops reliable yellow/gold fall color and is more resistant to linden aphids. As a younger tree itis less prone 
to winter sunscald than other lindens. When mature, the bark becomes mottled. You can expect this linden to reach approximately 35 feet tall and 25 feet wide. It is hardy to zones 3-4.
Crimson SpireTM Oak Quercus x ‘Crimschmidt’
This hybrid of white oak and columnar English oak is a good choice where there is a need for a tall, narrow tree. Crimson Spire™ oak has attractive blue-green leaves that are resistant to powdery mildew. Leaves turn rust-red in October for 2 weeks. The leaves then turn brown and persist into early spring. Hardy to Zone 5, you can expect this oak to reach 35 to 40 feet tall and 12 to 15 feet wide. It has shown some intolerance to wet soils.
