American Basswood (Linden)

Size, growth and what to expect

In a yard American basswood reaches 60 to 90 feet with a trunk 2 to 3 feet through and a crown 30 to 60 feet wide. Forest trees reach 130 feet. It gets there at a medium pace, roughly a foot and a half a year in its youth on an average site, which is the rate our growth estimator uses for it.

The first seed usually comes at 15 years or later, though trees have borne at 8, and one 26-year study found good crops in 62 percent of the years. Fragrant yellow-white flowers open for about two weeks in June and give an abundance of nectar for a choice honey, which is why beekeepers call it the bee tree. The fruit is a pea-sized nutlet hung from a strap-shaped bract, and mice, squirrels and chipmunks take the seed. Trees can live beyond 200 years, and the oldest known was ring-counted to 242. Most begin to decline at 90 to 140 years. The nutlets ripen in September and October and fall soon after.

It grows wild from New Brunswick west to Manitoba and south through the Dakotas and Kansas to Oklahoma, Arkansas, Tennessee and the North Carolina mountains.

How to grow American Basswood

American basswood wants deep, moist soil that drains, in full sun or part shade. It tolerates clay and does poorly on thin, droughty ground. This is a big shade tree with a wide crown, so plant it at least 30 feet from buildings and out from under wires. Set trees 30 feet apart.

Plant bare-root saplings while they are dormant. Dig a hole two to three times as wide as the root spread and only as deep, set the root flare at the soil line, and backfill with the same soil. Mulch a wide ring, kept clear of the trunk. Sow basswood seed outdoors in fall under hardware cloth against mice, but germination is slow and uneven, often waiting until the second or third spring.

Give a young linden a deep soak every week in its first summer and in dry spells for two more years. Deer browse it hard and rabbits girdle the bark, so keep a tube or wire guard on until the trunk is well above browse height.

Lindens do not set seed from their own pollen, and bees and flies carry pollen between trees, so plant two or more if you want seed. Basswood casts dense shade and drips aphid honeydew in some summers. Japanese beetles skeletonize the leaves without doing lasting harm. Leaves turn a soft yellow in fall.