Earth Notes: Mormon Mulberries

Mar 21, 2018

In springtime, the town of Saint George in southwest Utah is an island of green in a sea of rust-tinged rock. The verdant green is from shade trees planted by early Mormon settlers.  A sizable percentage of those are mulberry trees, according to professional arborist and former city forester Mark Hodges.

An old mulberry tree
Credit Thompson Mansion

Mormon pioneer Carolyn Jackson planted the first mulberry trees there in 1869 to feed silkmoth caterpillars, whose cocoons produced silk that was woven into cloth. Church leader Brigham Young promoted the industry to help create a self-sufficient Mormon society. He imported mulberry seeds and silkworm eggs from France, and some 100,000 mulberry trees were planted throughout Utah. 

Locals still make delicious jams from the fruit. But most consider them a nuisance because of the sticky, purple mess they leave. People often plant male mulberry trees that don’t produce fruit—but the downside is they leave clouds of allergy-producing pollen when they flower.

Mulberries, though not native, are important biologically too. Robins and other birds feed on the large fruit. In a fascinating turnabout, some mulberry trees can change sex in different years; they can even bear male and female flowers simultaneously. But the region’s hot climate and brilliant sunlight favor maleness.

Some grand old mulberries still survive in Saint George, including one at Brigham Young’s winter residence. In autumn, the trees shed all their leaves at once. On Leaf Drop Day children frolic in the mounds of fallen leaves and their elders remember a past industry.