Dr. Michael Dirr’s Latest Findings: Magnolia Virginiana- Sweetbay Magnolia

In previous tree profiles, I discussed Magnolia acuminata and M. × soulangeana and herein highlight an increasingly important landscape species, M. viginiana. It is becoming

Read More

Dr. Dirr’s Tree Spotlight: Quercus Lyrata-Overcup Oak

The overcup oak, Quercus lyrata, languished in landscape obscurity until the 1990s when several Georgia nurserymen realized and developed its potential. The University of Georgia

Read More

Dr. Dirr Tree Spotlight: Magnolia x soulangeana- saucer magnolia

The hope of spring is tethered to this species and the many cultivars. Difficult to imagine a garden, park, campus, golf course, city street, commercial

Read More

Dr. Dirr’s Tree Spotlight: Liriodendron tulipifera (Tuliptree)

From the arborists’ point of view, the tuliptree has more than its share of liabilities including excessively fast growth, limb breakage, drought-induced premature leaf abscission,

Read More

Dr. Dirr’s Tree Spotlight: Acer triflorum – Three-flower Maple

A beautiful maple, resoundingly/photogenically magnificent in shades of orange and red in autumn. Colors long persistent, from initiation to the crescendo, easily 3 to 4

Read More

Dr. Dirr Tree Spotlight: Thuja occidentalis-Eastern Arborvitae

Dr. Dirr’s thoughts on the Eastern Arborvitae: Not quite sure why I never fully respected this soft-textured needle evergreen but an epiphany occurred during a

Read More

Styrax japonicus-Japanese snowbell

Beyond redbuds, Cercis, dogwoods, Cornus, flowering crabapples, Malus, and magnolias, Magnolia, there are precious few genera which offer significant cultivar diversity. Within eastern redbud, ~35

Read More

Dr. Dirr Spotlight: Pyrus calleryana- Callery pear and invasiveness

Touted as the biological savior for stressful environments since the introduction of ‘Bradford’ in January, 1960.  Profuse white flowers in spring, shining dark green summer

Read More

Dr. Dirr’s Tree Spotlight: Ulmus americana

Without equivocation, the American elm was the dominant street, shade and urban tree species in North America until the introduction of Dutch elm disease. Embedded

Read More

Dr. Dirr’s Tree Spotlight: Quercus bicolor

The North American deciduous forest is rich with oak diversity such as Quercus bicolor. Oaks are categorized as belonging to the White or Red /Black

Read More