The Cucumber tree, Magnolia acuminata, often spelled as a single word "Cucumbertree", is one of the largest magnolias, and one of the cold-hardiest. It is a large forest tree of the northeastern United States and southeasternmost Canada. It is a tree that tends to occur singly as scattered specimens, rather than in groves.

The Cucumber tree is native primarily within the Appalachian belt, including the Allegheny Plateau and Cumberland Plateau, up to western Pennsylvania and New York. There are also numerous disconnected outlying populations through much of the southeastern U.S., and a few small populations in southernmost Ontario.

The leaves are deciduous simple and alternate, oval to oblong, 12-25 cm long and 6-12 cm wide, with smooth margins and downy on the underside. They come in two forms, acuminate at both ends, or moderately cordate at the base (these are usually only formed high in the tree).

Unlike most magnolias, the flowers are not showy. They are typically small, yellow-green, and borne high in the tree. The name Cucumber tree comes from the unripe fruit, which is green and often shaped like a small cucumber; they mature dark red, 6-8 cm long and 4 cm broad, with the individual carpels splitting open to release the bright red seeds.

Uses and cultivation

Cucumber trees make excellent shade trees for parks and gardens, though they are not recommended for use as street trees. In cultivation, they typically only grow 15-20m (50-75 feet) tall, although they reach over 30m (100 feet) in forest situations. However, they can become massive, with the national champion in Stark County, Ohio measuring more than ten feet in diameter (although only seventy-nine feet tall). They are tolerant of alkaline soils, but require it to be deep, moist, and well-drained. This tree needs protection from extreme wind and heat.

They are tricky to transplant due to their coarse, fleshy root system and should be planted shallow and moved in early spring with a good soil ball.

In the timber trade, this tree is interchangeable with that of the related Tulip tree (Liriodendron tulipifera).

References

• Sternberg, Guy, (2004) Native Trees for North American Landscapes pp. 264. Timber Press, Inc.