Although the conspicuous blossoms of the magnolias often conjure up images of the Old South, they are right at home in Highland Park. The blooming season begins in late April with the star magnolias followed in May by the saucer magnolias. Many of the American magnolias, including the sweet bay and bigleaf magnolias, flower during June and July. Thirty-five magnolias species, varieties or forms are represented in Highland Park, including two endangered species native to the southeastern United States: the Ashe & Fraser.

At Highland Park, the magnolias are located on the protected slope just south of the reservoir.