In contrast to other magnolia varieties, it grows as a single-stemmed tree, as its name suggests. If the location is advantageous, the tree magnolia can reach a height of up to 10 m and a width of around 6 m. This magnolia is particularly effective as a solitary tree. While it initially has a rather conical growth, over the years its crown spreads out into a broad, rounded shape.

The elegant flowers of the Magnolia kobus appear in large numbers from April to May. Its narrow, white petals are strongly reminiscent of those of the star magnolia (Magnolia stellata), to which it is also related. The approximately 10 cm large flowers exude a delicate scent. The foliage of this magnolia only develops after flowering. The obovate leaves have a fresh green color and are about 15 cm long. Before they are shed in autumn, they shine in a bright yellow.