Cucumber Magnolia

Size, growth and what to expect

At maturity a cucumber magnolia stands 60 to 80 feet with a trunk about 2 feet through, and it can reach 100 feet on the deep soils of a mountain cove. It grows fast, nearly three feet a year in its youth on an average site, the rate our growth estimator uses for a fast tree.

A seedling may take 12 or more years to bloom, and seed bearing begins at about 30 years. The heaviest crops come after 50, with a good one every 4 to 5 years. The greenish-yellow flowers are 2 to 4 inches long. The knobby fruit is 2 to 3 inches long and holds 10 to 60 red seeds that grackles, blackbirds and small mammals clean out. The tree seldom lives more than 150 years, though the oldest known, dated by its rings, reached 520. It flowers between early April and early July, depending on location.

It grows wild on cool moist mountain sites from western New York and southern Ontario southwest to Indiana, Missouri and Louisiana, and east to northwest Florida and Georgia. In the mountains it runs north to Pennsylvania.

How to grow Cucumber Magnolia

Cucumber magnolia takes full sun or part shade and wants deep, average soil that drains but holds moisture through summer. This is a forest tree with a spreading crown, so plant it 40 feet from the house and clear of wires, where it will never need cutting back. Set trees 35 feet apart.

Saplings ship potted, with the root ball whole. Plant while dormant, and if you have the choice, plant at the end of winter rather than in fall, since the thick, fleshy roots heal slowly in cold ground. Dig wide and no deeper than the roots, keep the root flare at grade, use the soil you dug, and mulch a wide ring off the trunk. Clean the pulp from the red seed, sow it in fall, and never let it dry.

Water through the first two summers. Mulch instead of cultivating, because surface roots damage easily. Rabbits and deer browse young trees, so cage the stem for the first few years and prune as little as possible.

A lone cucumber magnolia sets less seed than trees that can cross with a neighbor, so plant two or more seedlings if you want seed. The greenish flowers sit high in the crown and are easy to miss, and a seedling takes many years to bloom. The knobby fruit reddens in late summer and birds clear the seeds quickly.