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The Journal Gazette

Saturday, September 30, 2017 1:00 am

White mulberry tree is invasive

Ricky Kemery

Q. I have a mulberry tree in my backyard. My one neighbor says it is an invasive tree, and another says it is a native tree and good to have. Which neighbor is correct?

Answer: Your mulberry tree looks like a white mulberry. According to Sally S. Weeks, dendrologist at the Department of Forestry and Natural Resources at Purdue University, white mulberry is a prolific fruit producer and is often found in open sunny sites. Red mulberry is a rare native tree most often found in shady moist sites in mature woods.

White mulberry is native to China. The tree was introduced in the Long Island, New York, area in 1827 and was planted in many areas of the eastern United States as a potential food source for the silkworm. Unfortunately, the costs to produce silk in the U.S. were too high, and this get-rich scheme failed.

The white mulberry flourished in our temperate climate. Birds and other animals ate the mulberry fruit and quickly spread the seeds – and the tree  – to other areas. The saplings have a deep taproot and are very difficult to pull, even at a small size.

White mulberries are generally found in sunny areas and are found more in the northern half of Indiana. Many folks think white mulberries have white fruit. It is more common for white mulberry to have red to purple fruit that may turn white at maturity.

White mulberry can be invasive and can overtake areas such as fence rows. As always, one person's weed can be another person's treasure.

All of the mulberries have leaves that occur in three shapes – entire, mitten and three-lobed leaves.

Mulberry is a dioecious species, composed of male (creamy) and female (green) flowers borne on separate trees in mid-spring. Fruits mature quickly on female trees, maturing in early to mid-summer and are relished by birds, squirrels and other mammals.

White mulberry leaves are often shiny and bright green above, with larger more rounded teeth than red mulberry.

Red mulberry, our native tree, is primarily found in southern Indiana. The leaves are usually larger than white mulberry, and are quite rough on the upper surface. The tree is intolerant of sunny conditions.

Red mulberry fruit is delicious, but the fruit is produced in less quantity than white mulberry. The fruit is found along the twigs, unlike white mulberry whose fruit is found in clusters at the ends of the twigs. I always could identity white mulberry by the orange to reddish inner bark; compared to tan inner bark of red mulberry.

Red mulberry bark has fibers in it, which were made into cloaks by the Choctaws. They were also used to make ropes for the ships of the Spanish conquistadors.

Illinois Everbearing, Collier, Weeping, Beautiful Day and Geraldi Hybrid are hybrids between red and white mulberry and can be found at some specialty nurseries.

The Plant Medic, written by Ricky Kemery, appears every other Saturday. Kemery retired as the extension educator for horticulture at the Allen County branch of the Purdue Extension Service.